Feeding Dairy Cows: In Vitro NDF Digestibility


Introduction

This fact sheet has been developed to support the implementation of the Natural Resources Conservation Service Feed Management 592 Practice Standard. The Feed Management 592 Practice Standard was adopted by NRCS in 2003 as another tool to assist with addressing resource concerns on livestock and poultry operations. Feed management can assist with reducing the import of nutrients to the farm and reduce the excretion of nutrients in manure.

The Natural Resources Conservation Service has adopted a practice standard called Feed Management (592) and is defined as “managing the quantity of available nutrients fed to livestock and poultry for their intended purpose”. The national version of the practice standard can be found in a companion fact sheet entitled “An Introduction to Natural Resources Feed Management Practice Standard 592”. Please check in your own state for a state-specific version of the standard.

Conclusions reached regarding in vitro neutral fiber digestibility (IVNDFD) and its impact on lactation performance in a literature review for a symposium presentation at the 2006 ADSA/ASAS Annual Meeting (Shaver, 2006) were as follows:

  • IVNDFD has been related to > milk production across an array of different forages.
  • Milk production response to IVNDFD is thru DMI, and not energy density.
  • DMI and milk production responses to IVNDFD > in higher producing cows.
  • Benefits of brown midrib corn & sorghum silages for IVNDFD, DMI, and milk production have been observed consistently.
  • More IVNDFD/in vivo research is needed with legumes & other grasses.
  • Increased IVNDFD has not been fully exploited by researchers in trials attempting to maximize dietary forage or optimize forage mixtures, or by field nutritionists feeding higher forage diets with the aim of improving cow health.

Please check this link first if you are interested in organic or specialty dairy production

IVNDFD Analysis

Several commercial testing laboratories offer wet chemistry IVNDFD measurements. Ranges for IVNDFD of forages are presented in Table 1. The IVNDFD values are highly variable among and within forage types. Introduction of low-lignin, brown midrib hybrids for production of corn and sorghum silages has widened the variation in IVNDFD for these forage types (Oba and Allen, 1999b). NIRS calibrations for predicting IVNDFD on hay-crop forage and corn silage samples are available at some commercial forage testing laboratories. However, Lundberg et al. (2004) found poor prediction by NIRS of legume-grass silage and corn silage IVNDFD. It is hoped that NIRS calibration equations can be improved upon in the future.

The NRC (2001) recommended a 48-h IVNDFD for use in the NRC (2001) model, and for that reason we used 48-h IVNDFD measurements in MILK2000 (Schwab et al., 2003). However, debate continues within the industry about the appropriateness of 48-h vs. 30-h IVNDFD measurements. Some argue that the 30-h incubation better reflects ruminal retention time in dairy cows (Oba and Allen, 1999a) and that most of the in vivo trials that have evaluated effects of varying IVNDFD on animal performance also performed 30-h IVNDFD measurements (Oba and Allen, 2005). Labs and their customers also like the faster sample turn around that is afforded by the 30-h incubation time point. For that reason, and also for improved lab operation efficiency, a 24-h incubation time point is being employed by some labs. However, some argue that the 48-h incubation time-point is less influenced by lag time and rate of digestion, and thus is more repeatable in the laboratory (Hoffman et al., 2003). Hoffman et al. (2003) provided data on the relationship between 30- and 48-h IVNDFD measurements that showed a strong positive relationship (r-square = 0.84). But, the lab average at a specific incubation time point and the relationship between incubation time points within a lab can be highly variable among labs making the development of a universal incubation time point adjustment equation difficult. The average lignin-calculated corn silage NDF digestibility in the NRC (2001) is 59%. This reference point is important for adjustment of IVNDFD values from different labs and varying incubation time points so that the resultant TDN and NEL values are comparable to NRC (2001) values.

Average IVNDFD values for selected high-fiber by-product feeds (Peter Robinson, CA-Davis, personal communication) are presented in Table 2. The IVNDFD values are highly variable among these high-fiber by-product feeds. The IVNDFD values for these high-fiber by-product feeds were poorly related to lignin-calculated (NRC, 2001) NDF digestibility. High digestible NDF (dNDF; % of DM) for soy hulls and beet pulp relative to other high-fiber by-products suggest a high potential for using these ingredients at reasonable inclusion rates to partially replace forage with low fiber digestibility to increase diet dNDF. Monitoring and maintaining effective NDF in the diet is critical when employing this feeding strategy.

The distribution of 48-h IVNDFD for high-group TMR samples from commercial dairies analyzed at the University of Wisconsin Forage Testing Laboratory (Marshfield, WI; Hoffman, 2003) is presented in Figure 1 with an average IVNDFD of 57.2% of NDF. The IVNDFD range for these high-group TMR samples is wide and raises concern over intake limitations on the low end and lack of effective fiber on the high end. Analyzing for IVNDFD offers another tool for troubleshooting fiber status of dairy cattle diets.

Table 1. Variation within forages for neutral detergent fiber digestibility measured in situ or in vitro.
Forage IVNDFD (% of NDF)
Nocek and Russell, 1998 Legumes 31-63
Grasses 41-77
Corn Silage 32-68
Allan and Oba, 1996 Alfalfa 25-60
Whole-Plant Corn 30-60
Hoffman, 2003 (UWFTL) Legumes 35-65
Grasses 25-75
Corn Silage 40-75
Chase, 2003 (Dairy One) Legumes 34-57
Grasses 25-75
Corn Silage 45-64

 

Table 2. Content and digestibility of NDF for selected high-fiber by-product feeds.
Ingredient NDF, % DM1 IVNDFD, % NDF2 dNDF, % DM
Forages 40-60 30-60 10-35
Corn gluten feed 36 80(1)3 29
Distillers grains 39 75 (14) 29
Brewers grains 47 50(2) 24
Wheat midds 37 50(3) 19
Beet pulp 46 85(10) 39
Citrus pulp 24 85(2) 20
Soy hulls 60 90(2) 54
Whole cottonseed 50 50(36) 25
Cottonseed hulls 85 20(4) 17
Almond hulls 37 40(5) 15
1NRC, 2001.
230-h IVNDFD (% NDF) adapted from Dr. Peter Robinson, CA-Davis.
3(n).

 

Figure 1. Distribution of 48-h IVNDFD (% of NDF) in data set of 377 high-group TMR samples from commercial dairies analyzed at UW Soil & Forage Analysis Lab, Marshfield, WI (Hoffman, 2003).

 

References

  • Allen, M., and M. Oba. 1996. Fiber digestibility of forages. Pages 151-171 in Proc. MN Nutr. Conf. Bloomington, MN.
  • Arieli, A., and G. Adin. 1994. Effect of wheat silage maturity on digestion and milk yield in dairy cows. J. Dairy Sci. 77: 237-243.
  • Aydin, G., R. J. Grant, and J. O’Rear. 1999. Brown midrib sorghum in diets for lactating dairy cows. J. Dairy Sci. 82: 2127-2135.
  • Bal, M. A., R. D. Shaver, H. Al-Jobeile, J. G. Coors, and J. G. Lauer. 2000. Corn silage hybrid effects on intake, digestion, and milk production by dairy cows. J. Dairy Sci. 83: 2849-2858.
  • Chase, L. E. 2003. Update on forage digestibility. Page 25 in Proc. 2003 Dealer Seminars. Cornell Univ. Coop. Ext. Anim. Sci. Mimeo Series. No. 223.
  • Chow, L., M. Oba, V. Baron, and R. Corbett. 2006. Effects of advanced in vitro fiber digestibility of barley silage on dry matter intake and milk yield of dairy cows. J. Dairy Sci. 89(Suppl.1):263(Abstr.).
  • Dado, R. G., and M. S. Allen. 1996. Enhanced intake and production of cows offered ensiled alfalfa with higher neutral detergent fiber digestibility. J. Dairy Sci. 79: 418-428.
  • Dhiman, T. R., and L. D. Satter. 1997. Yield response of dairy cows fed different proportions of alfalfa silage and corn silage. J. Dairy Sci. 80: 2069-2082.
  • Grant, R. J., S. G. Haddad, K. J. Moore, and J. F. Pedersen. 1995. Brown midrib sorghum silage for midlactation dairy cows. J. Dairy Sci. 78: 1970-1980.
  • Hoffman, P. C. 2003. New developments in analytical evaluation of forages and total mixed rations. Proc. Symposium & Joint Mtg. Of WI Prof. Nutrient Applicators, WI Custom Operators, and WI Forage Council. WI Dells, WI.
  • Hoffman, P. C., Lundberg, K. L., L. M. Bauman, and R. Shaver. 2003. In vitro NDF digestibility of forages: The 30 vs. 48 hour debate. Univ. of WI Extension Focus on Forage Series. Vol. 5, No. 16. http://www.uwex.edu/ces/crops/uwforage/30vs48-FOF.htm.
  • Hoffman, P. C., S. J. Sievert, R. D. Shaver, D. A. Welch, and D. K. Combs. 1993. In situ dry matter, protein, and fiber degradation of perennial forages. J. Dairy Sci. 76: 2632-2643.
  • Kendall, C., and D. K. Combs. 2004. Intake and milk production of cows fed diets that differed in dietary NDF and NDF digestibility. J. Dairy Sci. 87(Suppl.1):340(Abstr.).
  • Ivan, S. K., R. J. Grant, D. Weakley, and J. Beck. 2005. Comparison of a Corn Silage Hybrid with High Cell-Wall Content and Digestibility with a Hybrid of Lower Cell-Wall Content on Performance of Holstein Cows. J. Dairy Sci. 2005 88:244-254.
  • Llamas-Lamas, G., and D. K. Combs. 1990. Effect of Alfalfa Maturity on Fiber Utilization by High Producing Dairy Cows. J. Dairy Sci. 73: 1069-1080.
  • Lundberg, K. L., P. C. Hoffman, L. M. Bauman, and P. Berzaghi. 2004. Prediction of forage energy content by near infrared reflectance spectroscopy and summative equations. Prof. Anim. Sci. 20:262-269.
  • Mertens, D. R., H. G. Jung, M. L. Raeth-Knight, and J. G. Linn. 2005. Impact of alfalfa hay neutral detergent fiber concentration and digestibility on Holstein dairy cow performance: I. Hay analyses and lactation performance – USDFRC. J. Dairy Sci. 88(Suppl.1):250(Abstr.).
  • National Research Council. 2001. Nutrient Requirements of Dairy Cattle. 7th rev. ed. Natl. Acad. Sci., Washington, DC.
  • Oba, M. and M. S. Allen. 2000. Effects of brown midrib 3 mutation in corn silage on productivity of dairy cows fed two concentrations of dietary neutral detergent fiber: 1. Feeding behavior and nutrient utilization. J. Dairy Sci. 83:1333-1341.
  • Oba, M. and M. S. Allen. 1999a. Effects of brown midrib 3 mutation in corn silage on dry matter intake and productivity of high yielding dairy cows. J. Dairy Sci. 82:135-142.
  • Oba, M. and M. S. Allen. 1999b. Evaluation of the importance of the digestibility of neutral detergent fiber from forage: effects on dry matter intake and milk yield of dairy cows. J. Dairy Sci. 82:589-596.
  • Oliver, A. L., R. J. Grant, J. F. Pedersen, and J. O’Rear. 2004. Comparison of brown midrib-6 and -18 forage sorghum with conventional sorghum and corn silage in diets of lactating dairy cows. J. Dairy Sci. 87: 637-644.
  • Raeth-Knight, M. L., J. G. Linn, H. G. Jung, D. R., Mertens, and P. R. Peterson. 2005. Impact of alfalfa hay neutral detergent fiber concentration and digestibility on Holstein dairy cow performance: II. Lactation performance – St. Paul. J. Dairy Sci. 88(Suppl.1):250(Abstr.).
  • Ruiz, T. M., E. Bernal, C. R. Staples, L. E. Sollenberger, and R. N. Gallaher. 1995. Effect of dietary neutral detergent fiber concentration and forage source on performance of lactating cows. J. Dairy Sci. 78: 305-319.
  • Schwab, E. C., R. D. Shaver. J. G. Lauer, and J. G. Coors. 2003. Estimating silage energy value and milk yield to rank corn hybrids. J. Anim. Feed Sci. Technol. 109:1-18.
  • Shaver, R. D. 2006. Forage intake, digestion and milk production by dairy cows. J. Dairy Sci. 89(Suppl.1):298(Abstr.).
  • Tessmann, N. J., H. D. Radloff, J. Kleinmans, T. R. Dhiman, and L. D. Satter. 1991. Milk production response to dietary forage:grain ratio. J. Dairy Sci. 74: 2696-2707.
  • Tine, M. A., K. R. Mcleod, R. A. Erdman, and R. L. Baldwin, VI. 2001. Effects of brown midrib corn silage on the energy balance of dairy cattle. J. Dairy Sci. 84: 885-895.

“Extension programs and policies are consistent with federal and state laws and regulations on nondiscrimination regarding race, sex, religion, age, color, creed, national or ethnic origin; physical, mental or sensory disability; marital status, sexual orientation, or status as a Vietnam-era or disabled veteran. Evidence of noncompliance may be reported through your local Extension office.”

Disclaimer

This fact sheet reflects the best available information on the topic as of the publication date. Date 5-25-2007

This Feed Management Education Project was funded by the USDA NRCS CIG program. Additional information can be found at Feed Management Publications.

Image:Feed mgt logo4.JPG This project is affiliated with the Livestock and Poultry Environmental Learning Center.

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Project Information

Detailed information about training and certification in Feed Management can be obtained from Joe Harrison, Project Leader, jhharrison@wsu.edu, or Becca White, Project Manager, rawhite@wsu.edu.

Author Information

Randy Shaver
Professor and Extension Dairy Nutritionist
Department of Dairy Science
College of Agricultural and Life Sciences
University of Wisconsin – Madison
University of Wisconsin – Extension

Reviewer Information

Jim Barmore – Nutrition Consultant
Pat Hoffman – University of Wisconsin

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Use of the Dairy Opportunity Checklist in Feed Management Plan Development

Introduction

This fact sheet has been developed to support the implementation of the Natural Resources Conservation Service Feed Management 592 Practice Standard. The Feed Management 592 Practice Standard was adopted by NRCS in 2003 as another tool to assist with addressing resource concerns on livestock and poultry operations. Feed management can assist with reducing the import of nutrients to the farm and reduce the excretion of nutrients in manure.

Please check this link first if you are interested in organic or specialty dairy production

The Natural Resources Conservation Service has adopted a practice standard called Feed Management (592) and is defined as “managing the quantity of available nutrients fed to livestock and poultry for their intended purpose”. The national version of the practice standard can be found in a companion fact sheet entitled “An Introduction to Natural Resources Feed Management Practice Standard 592”. Please check in your own state for a state-specific version of the standard.

The national Feed Management Education team has developed a systematic 5-step development and implementation process for the Feed Management Practice Standard. A complete description of the 5-steps can be found in a companion fact sheet entitled “Five Steps to the Development and Implementation of a Feed Management Plan”.

The second step of this process focuses on identifying the conditions where the practice applies and making an initial assessment of the opportunity for the full development of a Feed Management Plan. Key participants at step 2 would be the producer, the nutrient management planner, and NRCS staff.

The conditions where the practice applies as noted the in NRCS 592 standard include:

  1. Whole farm imbalance
  2. Soil nutrient build-up
  3. Land base not large enough, or
  4. Seeking to enhance nutrient efficiencies.

After defining the condition(s) for use of the 592 standard, an opportunity checklist (see pages 3-6) is then used make an initial assessment of developing a complete feed management plan.

The Opportunity Checklist is organized to first identify the resource concerns of:

  • Soil Condition – Animal Waste and other organics
  • Water Quality – Excessive Nutrients and Organics in Groundwater
  • Water Quality – Excessive Nutrients and Organics in Surface Water

If one or more of these conditions exist on an operation, then a FMP should be considered by completing the Opportunity Checklist.

The Opportunity Checklist is designed to determine the relative opportunity for feed management to impact Whole Farm Nutrient Management. The Opportunity Checklist is the first step in making a decision on whether to complete a FMP.

The checklist is meant to be used as an initial, quick, on-farm assessment tool. If the decision is made to complete a FMP, numerous additional feed management practices will be assessed in more detail with the use of the Feed management Plan Checklist.

The items shown in the Opportunity Checklist are the management practices which have the greatest opportunity for feed management to impact Whole Farm Nutrient Management. The ‘Benefit to the Environment’ column provides the possible impact the practice could have on whole farm nutrient management. It is meant to be informative and should not be answered for each farm.

If one or more of the Opportunity Checklist items are noted in the category of “moderate or lots of opportunity for improvement”, then the next evaluation step should be completed: Economic Evaluation (manure transport vs feed management change) or FMP Checklist.

Following on this fact sheet you will find a completed Opportunity Checklist as an example.

Dairy Opportunity Checklist:

Identify resource concerns and/ or conditions where practice applies and assess the Opportunities

Feeding management is one of six components of a Comprehensive Nutrient Management Plan (CNMP) as defined by the Natural Resource Conservation Service. Feeding management as part of a CNMP should be viewed as a “consideration” but not a “requirement” as some practices will not be economical on some dairies.

Resource concerns and the conditions where practice applies

Field specific resource concerns that may be impacted by feed management (but not limited too) are soil and water quality. For example, nutrients may build-up in the soil or leach into ground water due to manure application. Feed management practices with or without several other practices may reduce the volume and nutrient content of manure. If one or both of these resource concerns exist on an operation, then a Feed Management Plan (FMP) should be considered by completing the Opportunity Checklist.

Conditions where practice applies are whole farm imbalance, soil build-up of nutrients, land base not large enough, or operation seeking to enhance nutrient efficiencies. Feed management practices with or without several other practices may reduce the volume and nutrient content of manure and may be an effective approach to minimizing the import of nutrients to the farm. If one or more of these conditions exist on an operation, then a FMP should be considered by completing the Opportunity Checklist.

Opportunity Checklist

The Opportunity Checklist is designed to determine the relative opportunity for feed management to impact Whole Farm Nutrient Management. The Opportunity Checklist is the first step in making a decision on whether to complete a FMP. The checklist is meant to be used as an initial, quick, on-farm assessment tool. If the decision is made to complete a FMP, numerous additional feed management practices will be assessed in more detail.

The items shown in the Opportunity Checklist are the management practices which have the greatest opportunity for feed management to impact Whole Farm Nutrient Management. The ‘Benefit to the Environment’ column provides the possible impact the practice could have on whole farm nutrient management. It is meant to be informative and should not be answered for each farm. If one or more of the Opportunity Checklist items are noted in the category of “moderate or lots of opportunity for improvement”, then the next evaluation step should be completed: Economic Evaluation (manure transport vs feed management change) or FMP Checklist.

Dairy Information
Dairy Name
Date Completed
Producer Signature
Adviser Signature
Identify resource concern(s) and/ or the condition(s) where practice applies:
Resource Concern(s)
Soil Condition: Contaminants – Animal Waste and Other Organics

  • Nutrient levels from applied animal waste and other organics restrict desired use of the land.
Water Quality: Excessive Nutrients and Organics in Groundwater

  • Pollution from natural or human induced nutrients such as N, P, and organics (including animal and other wastes) degrades groundwater quality.
Water Quality: Excessive Nutrients and Organics in Surface Water

  • Pollution from natural or human induced nutrients such as N, P, and organics (including animal and other wastes) degrades surface water quality.
Conditions Where Practice Applies
Whole Farm Imbalance: Confined Dairy operations with a whole farm nutrient imbalance, with more nutrients imported to the farm than are exported and/or utilized by cropping programs.
Soil nutrient build-up: Confined Dairy operations that have a significant build up of nutrients in the soil due to land application of manure.
Land base not large enough: Confined Dairy operations that land apply manure and do not have a land base large enough to allow nutrients to be applied at rates recommended by soil test and utilized by crops in the rotation.
Dairy operations seeking to enhance nutrient efficiencies

Determine the Feed Management opportunities for addressing Resource Concerns:

On the following pages is a list of feeding management practices that can affect nutrient balance. Please read through each feeding management consideration and record your answer. If one or more of the Opportunity Checklist items are noted in the category of “moderate or lots of opportunity for improvement”, then the next evaluation step should be completed; economic evaluation or FMP Checklist.

Dairy Opportunity Checklist

Click here to view the Dairy Opportunity Checklist, example of the Dairy Information worksheet and an example Dairy Opportunity Checklist (PDF).

“Extension programs and policies are consistent with federal and state laws and regulations on nondiscrimination regarding race, sex, religion, age, color, creed, national or ethnic origin; physical, mental or sensory disability; marital status, sexual orientation, or status as a Vietnam-era or disabled veteran. Evidence of noncompliance may be reported through your local Extension office.”

Disclaimer

This fact sheet reflects the best available information on the topic as of the publication date. Date 5-25-2007

This Feed Management Education Project was funded by the USDA NRCS CIG program. Additional information can be found at Feed Management Publications.

Image:Feed mgt logo4.JPG

This project is affiliated with the LPELC.

Image:usda,nrcs,feed_mgt_logo.JPG

Project Information

Detailed information about training and certification in Feed Management can be obtained from Joe Harrison, Project Leader, jhharrison@wsu.edu, or Becca White, Project Manager, rawhite@wsu.edu.

Author Information

J. H. Harrison jhharrison@wsu.edu, and
R. A. White, Washington State University
A Sutton and Todd Applegate, Purdue University
Galen Erickson and Rick Koelsch, University of Nebraska
R. Burns, Iowa State University
D Wilks – Standard Nutrition

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Silage and Dry Hay Management

Introduction

This fact sheet has been developed to support the implementation of the Natural Resources Conservation Service Feed Management 592 Practice Standard. The Feed Management 592 Practice Standard was adopted by NRCS in 2003 as another tool to assist with addressing resource concerns on livestock and poultry operations. Feed management can assist with reducing the import of nutrients to the farm and reduce the excretion of nutrients in manure.

Forages stored as silage and dry hay crops can be in excess of 50% of the total dry-matter in a ration, and must have maximum nutrient availability in the tightly balanced rations fed to high-production dairy cows. Feeding high quality forages minimizes nutrient loss of the livestock enterprise through nutrient conservation either in the hay bale or in the silo, and by how well the animal utilizes nutrients from preserved forages during digestion.

Please check this link first if you are interested in organic or specialty dairy production

Ensiled Forages

Oxygen consuming aerobic and non-oxygen consuming anaerobic bacteria are involved in silage fermentation. Aerobic activity occurs while the silo is being filled and at feedout and are the primary times when dry matter losses occur in the silo. Good silo management minimizes aerobic activity, thus reducing dry-matter losses and maximizes the anaerobic conversion of water-soluble carbohydrate to silage acids, reducing pH to a range that is inhospitable to spoilage organisms. Silage fermentation can be divided into six phases.

Forage Quality Fig 1.jpg

Phase 1

The first phase begins when the plant is harvested. During this phase, aerobic micro-organisms coming in with the crop cause nutrient loss by converting water-soluble carbohydrates to carbon dioxide, water, and heat. In addition, other gases are produced, due to the enzymatic proteolysis of protein, that have environmental concerns such as ammonia nitrogen and various forms of nitrogen oxides. Phase 1 fermentation continues until either oxygen is depleted or water-soluble carbohydrate is exhausted. Aerobic activity should last only a few hours if ideal ensiling moisture, chop length, compaction, and covering management guidelines are practiced by the silage management team.

Phase 2

Depletion of trapped oxygen during the initial aerobic phase triggers the second anaerobic phase of fermentation with the production of several fermentation end-products. These bacteria produce short-chain volatile fatty acids (acetate, lactate, propionate, and butyrate), ethanol, and carbon dioxide. In addition, more nitrogenous end-products can be generated due to continued enzymatic proteolysis of protein as described during the aerobic phase. The phase 2 bacteria tend to be inefficient fermenters, contributing to dry matter losses of forages stored in silos. The proportions of fermentation end-products produced depend on crop maturity, moisture, and epiphytic bacterial populations of the harvested forage.

The 2nd phase bacteria create an environment for another more efficient class of anaerobic bacteria, commonly known as lactic acid bacteria (LAB). An initial drop in pH signals the end of the early anaerobic phase, which generally lasts no longer than 24 to 72 hours.

Phases 3-4

Phases three and four of fermentation occur when LAB convert water-soluble carbohydrate to lactic acid. As the heat generated in phase 1 starts to dissipate and pH becomes lower, other LAB will become active in the production of lactic acid. This acid is the strongest and most efficient volatile fatty acid for rapidly reducing pH. Lactic acid generally predominates in the best-quality silage (more than 60% of the total volatile fatty acids) and can be present at levels as high as 3% to 6% of dry matter. A predominance of LAB relative to other silage acid producing bacteria creates a faster fermentation, conserving more nutrients in the form of water-soluble carbohydrate, peptides, and amino acids. Anaerobic phases continue until forage pH is sufficiently low to inhibit, but not destroy, the growth potential of all organisms. Natural fermentation accomplished solely by epiphytic organisms and unassisted by any type of silage additive takes 3-7 days in corn silage and 7-14 days with legume silages. This time span depends on the buffering capacity, moisture, and maturity of the crop to be ensiled. The rate and end-point of the final pH drop in the ensiled crop depends largely on the type and moisture of forage being ensiled. Corn silage pH terminates at or below pH 4. Legumes, which have less water-soluble carbohydrate content and a higher buffering capacity, generally reach a terminal pH of approximately 4.5. When terminal pH is reached, the forage is in a preserved state.

Phase 5

The fifth stage of fermentation, the stable phase, lasts throughout storage. This phase is not static because other anaerobic bacteria become active during this period producing end-products that: 1) are anti-mycotic and will be conducive to bunklife stability and 2) will enhance starch and fiber digestibility of silages during feedout. Silage management practices resulting in high silage densities, maintaining silo structure integrity, and face management dictates the efficiency of phase 5 fermentation.

Phase 6

The final fermentation phase, occurs when silage is fed from the storage structure. This phase is as important as the others but is often neglected. Up to 50% of dry-matter losses result from secondary aerobic spoilage on the surface of the silage in storage and in the feedbunk. Aerobic microbial activity is stimulated because oxygen is introduced into the silo. The aerobic activity produces heat and reduces the palatability and nutrient availability of silage. Bunklife challenges increase with high application of manure that may have inoculated the crop with mold and yeast spores. Forages wilting in swaths and windrows can become contaminated with soil-borne organisms through raking or by rain splashing soil onto the swaths. Aerobic stability of silage is more of a problem if the crops had been exposed to environmental stresses.

Harvesting, Ensiling, and Feedout

There are nine rules for successful fermentation. First, the storage structure must be of the correct size so that silage removal rates can be maintained at least 6 inches per day for bunker and piled silos. The feedout rate for upright silos is 4 to 6 inches/day in summer and 2 to 4 inches/day in the winter.

The second and third management rules are to harvest at proper maturity and moisture level. Table one lists recommendations based on crop and type of storage structure. Proper maturity and moisture provides optimal nutrition for dairy production, more water-soluble carbohydrates, and promotes the elimination of oxygen to maximize anaerobic fermentation.

Forages ensiled at moisture levels greater than 70% may undergo undesirable secondary clostridial fermentation. Wet forages have a low concentration of water-soluble carbohydrate. Thus, anaerobic bacteria may not have enough sugar to produce sufficient volatile fatty acids to achieve a pH below 5. A pH over 5 creates an environment suitable for secondary fermentation by clostridia. These anaerobes degrade lactate and amino acids and produce butyric acid (which is a weaker acid). They also consume lactate (thus causing terminal pH to rise) and yield an unpalatable, rancid silage.

Clostrial fermentation can produce silage with extended aerobic stability, it is nevertheless undesirable because it can break down amino acids and reduce palatability, which can reduce intake. Unwilted silages may require a pH near 4.0 to completely inhibit clostridial fermentation. Alfalfa and grasses are swathed at 80% to 85% moisture and require wilting to less than 70% before ensiling. Corn forage, in contrast, is chopped at the proper moisture and requires no wilt time.

Legumes and grasses must have proper wilt time between cutting and harvesting to permit evaporation of moisture. Wilting concentrates plant sugars essential for fermentation. Creating wide swaths during harvest permit a faster wilt time and conserves valuable plant sugars and protein nutrients. The following table from University of Wisconsin research shows that wide swaths conserves non-fiber carbohydrates (NFC) and results in higher relative forage quality (RFQ). Merging equipment is then used to build windrows just before chopping the crop.

Difference in composition of alfalfa haylage made from narrow and wide swaths, UW Arlington, 2005
Undersander, University of Wisconsin
Factor Wide Narrow Difference
NDF, % 37.8 40.1 -2.3
NFC, % 38.4 36.5 1.8
Ash, % 9.3 9.9 -0.6
TDN, 1x 63.5 62.6 0.9
Lactic acid, % 5.6 4.6 1.0
Acetic acid, % 2.4 1.9 0.5
RFQ 166 151 15

The fourth rule is that chopper knives must be sharp and the shearbar properly adjusted for desired theoretical length of cut (TLC). Sharp knives ensure a clean chop and prevent shredding, decreasing chances of effluent production. Table one suggests lengths of cut for various forages. This adjustment is critical to maximize forage compaction for efficient fermentation while providing sufficient particle length for proper rumination. If corn forage crops are kernel processed, the roller mill settings must be adjusted so that all corn kernels are fractured during harvest. The shearbar TLC is usually longer with processed corn silage compared to non-processed for providing better source of effective fiber to the dairy or beef animal.

The fifth rule is that the structure must be filled as rapidly as possible to diminish phase 1 losses. Bunker silos and piles should not have more than a 3:1 slope on sides and ends so that proper packing is achieved during silo filling.

The sixth rule is to pack silage bunkers and piles so that at least 800 lbs of tractor weight is used per hour per ton. For example, if 100 tons of forage is delivered to the silo/hr, then a tractor with 80,000 lbs (100 X 800) of pack weight or 40 tons needed to meet packing needs. No more than 6 inches of forage should ever be packed at any given time. Tractor weight delivered to forage is drastically lessened when silage depths are in excess of 6 inches. The person on the pack tractor has the most important role in filling bunker silos. Packing ensures the elimination of oxygen, thus minimizing aerobic activity and maximizing anaerobic fermentation.

The seventh rule is to seal the silo properly. A plastic tarp is usually used to cover the entire bunker surface, and a net of tires holds the tarp in place. Double sheets of tarp and lining the bunker walls with tarp will further reduce dry matter losses during fermentation. A new “saran wrap” cling type plastic known as Silo-Stop® is available for placement between the silage surface and tarp, which will further mitigate surface spoilage losses. Kansas State research shows that dry matter losses in the top four feet of uncovered horizontal silos can be in excess of 33% while normal dry matter losses are about 15%. A favorable return on investment for covering exists by minimizing the amount of surface dry-matter losses.

The eighth rule is to maintain a proper feedout rate. Losses resulting from slow removal account for up to 50% of dry-matter losses, which will be in the form of plant sugars, not fiber. Aerobic organisms consume water-soluble carbohydrate, thus reducing the energy content of the forage.

Silages should be removed from bunker and pile faces by shaving the silage face from top to bottom with the loader bucket rather than by lifting the bucket from the bottom to the top. Lifting creates fracture lines in the stored mass, thus allowing oxygen to enter and sustain aerobic activity. Even if farmers remove a desirable 6 inches from the silo face every day, oxygen may penetrate several feet into the stored mass allowing aerobes to generate heat. Consequently, farmers cannot get ahead of aerobic instability.

Silage additives should only be used as the ninth rule if the other conditions for producing high-quality silage can be met. The most common additives are bacterial inoculants, enzymes, acids, and nutrients. Good silage can be made better through the proper use of effective silage additives.

Dry Haycrop Forages

Haycrop preservation is a result of moisture reduction, which creates an environment unsuitable to spoilage from microbial activity. Haycrops dry in 3 phases. Phase 1 is very rapid loss of moisture down to 60-65% moisture. Phase 2 is a slower process down to about 40% moisture. Phase 3 is the longest phase reaching moistures levels that can be safe for storing dry hay. Hay does not become static until it reaches about 12% moisture and the equilibrium humidity is below 65% at which time most fungi will not grow.

If hay is baled at higher moistures and not protected by a preservative or inoculant, several peaks of heating may occur. The first temperature peak will generally occur within a few days and can be the result of aerobic bacterial growth, fungal growth and/or plant respiration. If oxygen and a favorable moisture level are available, microorganisms begin to multiply, generating heat up to 130 to 140 F. The rise in temperature tends to kill most microorganisms resulting in the gradual decline in internal bale temperatures. The initial heating in hay baled at lower moistures typically drives off moisture. However, in higher moisture bales, the hay moisture combines with water generated in the respiration process, allowing for unusually prolonged conditions that prove optimum for bacterial and fungal growth. The magnitude of peak temperatures will usually be lower each time. Eventually the temperature will stabilize near ambient temperature. These secondary temperature peaks are generally the result of fungal growth. Aerobic fungi are the primary microbes responsible for the breakdown of complex carbohydrates and subsequent generation of heat.

Harvest and Storage Losses

Storage losses are directly related to microbial growth and to subsequent heating. The extent of heating depends largely on: (1) the moisture of the hay, (2) the density and size of the bale, (3) the rate of bale dry-down and (4) the microbial populations that came in with the crop. Microbial activity in hay does not terminate at baling, especially when baling at higher moistures (20-30%) to reduce leaf shatter losses.

Respiration Losses

Cells of cut forages are alive and functioning until the moisture content reaches about 47-48%, below which the cells die. If drying conditions are poor and the cells live a relatively long time, carbohydrates will be depleted and forage quality is diminished. Under good drying conditions, respiration accounts for 2-8% loss in dry matter with losses up to 16% under slow drying conditions.

Management practices that shorten drying time resulting in reduced respiration and harvest losses include: 1) cutting early in the day to maximize solar drying (although plant sugars are lower during morning hours), 2) cutting when anticipated weather will allow for relative humidity of the air to be below the equilibrium humidity of the forage, 3) mechanical or chemical conditioning to crush stems for water escape and 4) maximizing hay exposure to wind and sunlight by creating wide and thin windrows.

Weather Losses

Rain lowers the quality of hay through leaching of water-soluble carbohydrates and prolonging respiration losses. The extent of leaching loss is influenced by several factors including type of forage, stage of maturity, moisture content at the time of rainfall, amount of rainfall, frequency of rain and mowing/conditioning treatments. Alfalfa harvested in the bud stage undergoes more extensive leaching loss than hay harvested in full bloom presumably because the amount of soluble nutrient decrease as the alfalfa plant matures.

Mechanical Losses

Mechanical losses can range from 8-45% and is due to “leaf shatter”. Alfalfa leaves dry down 2-1/2 to 5 times faster than stems and as plant moisture decreases to below 30%, leaves become extremely brittle. Leaf loss is nutritionally important because alfalfa leaves comprise approximately 50% of the crop dry matter and contain over 70% of the plant protein, and 65% of the digestible energy. The extent of mechanical leaf loss is dependent upon crop maturity, moisture content, and rake or baler design. Nearly 50% of the total mechanical losses occur during mowing-conditioning and raking. The final field operation also causes reduction in dry matter yields. Losses from conventional, small rectangular balers range from 3-8% while large baler losses may be as high as 15 percent.

Storage Losses

Hay stored at less than 15% moisture and stored under cover will have up to 10% dry matter losses. When baling moisture exceeds 20%, excessive heating due to spoilage microorganisms result in a browning reaction which reduces the nutritive value of the hay. Excessive heat damage can reduce protein and energy digestibility of the hay.

Mold growth in improperly cured hay can adversely affect palatability and feed intake, although less than 5% of the molds commonly found in hay produce any mycotoxin. Feeding moldy alfalfa hay results in significantly lower dry matter intake, reduced weight gains and poorer feed conversion compared to feeding mold-free hay.

Table 1. Harvest and Moisture Recommendation Table
—–Silo Type—–
Crop Maturity Horizontal Stave Sealed Length of Cut
Silage Crops ……..% moisture…….. inches
Corn Silage Milk line 1/2 – 3/4 Down the kernel (Verify with whole plant DM determination)
Non-Processed 65-72 63-68 50-60 3/8 – 1/2
Processed 62-70 62-68 50-60 3/8 – 3/4
Alfalfa Mid-bud 1/10 bloom and wilt to –> 60-70 63-68 40-60 1/4 – 1/2
Cereal silage Milk or soft dough and wilt to –> 67-72 63-68 55-60 1/4 – 1/2
Grasses When first stems head out 60-70 63-68 40-60 1/4 – 1/2
Forage sorghum Grain medium to hard dough or as leaves begin to lose color 62-72 63-70 60-70 3/8 – 1/2
Dry Hay Crop Bale Type Moisture Range
Alfalfa Mid-bud 1/10 bloom Large Round/
Mid-Square
Preser-
ative
No Treatment
Grass When first stems head out Large, Square Bales 13 – 20% <13%
Cereal Milk or soft dough Small, Square Bales 13 – 18% <13%

Selected References

Mahanna, W.C. 1994. Hay Additive Review: Where We’ve Been, Where We’re Going. 24th National Alfalfa Symposium. Feb. 24-25, 1994, Springfield , IL.

Seglar, W.J. 1997. Dairy Production Management-Silage Management. Veterinary Compendium-Food Animal Medicine and Management, Feb. 97.

“Extension programs and policies are consistent with federal and state laws and regulations on nondiscrimination regarding race, sex, religion, age, color, creed, national or ethnic origin; physical, mental or sensory disability; marital status, sexual orientation, or status as a Vietnam-era or disabled veteran. Evidence of noncompliance may be reported through your local Extension office.”

Disclaimer

This fact sheet reflects the best available information on the topic as of the publication date. Date 2-2007

This Feed Management Education Project was funded by the USDA NRCS CIG program. Additional information can be found at Feed Management Publications.

Image:Feed mgt logo4.JPG

This project is affiliated with the LPELC.

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Project Information

Detailed information about training and certification in Feed Management can be obtained from Joe Harrison, Project Leader, jhharrison@wsu.edu, or Becca White, Project Manager, rawhite@wsu.edu.

Author Information

William J. Seglar DVM, PAS
Nutritional Sciences
Pioneer Hi-Bred International, Inc.
7100 NW 62nd Ave, PO Box 1100
Johnston, Iowa 50131-1100
Bill.Seglar@pioneer.com

Reviewer Information

Brad Harman – Pioneer Hi-Bred International

Greg Zuver – Nutrition Consultant

Partners

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Use of the Dairy Feed Management Plan Checklist in Feed Management Plan Development

Introduction

This fact sheet has been developed to support the implementation of the Natural Resources Conservation Service Feed Management 592 Practice Standard. The Feed Management 592 Practice Standard was adopted by NRCS in 2003 as another tool to assist with addressing resource concerns on livestock and poultry operations. Feed management can assist with reducing the import of nutrients to the farm and reduce the excretion of nutrients in manure.

The Natural Resources Conservation Service has adopted a practice standard called Feed Management (592) and is defined as “managing the quantity of available nutrients fed to livestock and poultry for their intended purpose”. The national version of the practice standard can be found in a companion fact sheet entitled An Introduction to Natural Resources Conservation Service (NRCS) Feed Management Practice Standard 592. Please check in your own state for a state-specific version of the standard.

The national Feed Management Education team has developed a systematic 5-step development and implementation process for the Feed Management Practice Standard. A complete description of the 5-steps can be found in a companion fact sheet entitled Five Steps to the Development and Implementation of a Feed Management Plan.

The fourth step of this systematic process focuses on the development of the Feed Management Plan. Key participants at step four are the producer and their nutritionist. The key tools to be used at step four are the Feed Management Plan (FMP) Checklistand the Feed Management Plan Template. This fact sheet will concentrate on using the checklist. The next fact sheet in this series A National Template for Preparing a Dairy Feed Management Plan will discuss the template.

Please check this link first if you are interested in organic or specialty dairy production

Using the Feed Management Plan Checklist

The FMP checklist is designed to assist dairy operators and their nutrient management advisor to determine feeding management factors that affect nutrient management. The checklist is meant to be used as an on-farm assessment tool. The factors contained in this assessment can be used as a guide to document and identify feeding management practices that will impact whole farm nutrient management.

The FMP checklist is designed to assist dairy operators and their nutrient management advisor to determine feeding management factors that affect nutrient management. The checklist is meant to be used as an on-farm assessment tool. The factors contained in this assessment can be used as a guide to document and identify feeding management practices that will impact whole farm nutrient management.

The FMP checklist is designed to systematically gather information that can be used to develop the feed management plan. The organization of the checklist is divided into six management categories of:

  • targeting nutrient requirements
  • ration balancing
  • ration management practices
  • production aids/enhancers
  • monitoring tools
  • forage management practices

To use this checklist, each practice should be discussed with the operator: Are they already implementing the practice? If Yes, indicate so and skip to the next question. If No, discuss whether or not the practice could be implemented and consider the economic implications. In many cases the economic implications will be a “best professional” judgment by the consulting nutritionist or producer.

It is important to address the question “Will it be considered in the future?” as this can provide guidance for reviewing and updating the FMP in the future.

The ‘Benefit to the Environment’ column provides the possible impact the practice could have on whole farm nutrient management. It is meant to be informative and should not be answered for each farm.

By following this link you will find a blank copy of the Feed Management Plan Checklist (PDF file). Additionally, a Completed Feed Management Plan Checklist(PDF file)is available as an example.

The next step in the process is to write the Feed Management Plan. A fact sheet on developing the FMP is available at A National Template for Preparing a Dairy Feed Management Plan.

Related Files

To follow the references in this article, it is recommended that you print these PDF files and refer to them at the appropriate places in the article.
Feed Management Plan Checklist
Example Feed Management Plan Checklist(Dairy).

Disclaimer

This fact sheet reflects the best available information on the topic as of the publication date. Date 5-25-2007

This Feed Management Education Project was funded by the USDA NRCS CIG program. Additional information can be found at Feed Management Publications.

Image:Feed mgt logo4.JPG

This project is affiliated with the Livestock and Poultry Environmental Learning Center.

Image:usda,nrcs,feed_mgt_logo.JPG

Project Information

Detailed information about training and certification in Feed Management can be obtained from Joe Harrison, Project Leader, jhharrison@wsu.edu, or Becca White, Project Manager, rawhite@wsu.edu.

Author Information

Joe Harrison jhharrison@wsu.edu, and Becca White, Lynn Johnson-VanWieringen, and Ron Kincaid, Washington State University. Mike Gamroth, Oregon State University Tamilee Nennich, Texas A&M University.

Partners

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Acknowledgments

This Feed Management Education Project was funded by the USDA NRCS CIG program. Additional information can be found at Feed Management Publications.
This project is affiliated with the Livestock and Poultry Environmental Learning Center

usda,nrcs,feed_mgt_logo.JPG

 

“Extension programs and policies are consistent with federal and state laws and regulations on nondiscrimination regarding race, sex, religion, age, color, creed, national or ethnic origin; physical, mental or sensory disability; marital status, sexual orientation, or status as a Vietnam-era or disabled veteran. Evidence of noncompliance may be reported through your local Extension office.”

Whole Farm Nutrient Management – A Dairy Example

Introduction

This fact sheet has been developed to support the implementation of the Natural Resources Conservation Service Feed Management 592 Practice Standard. The Feed Management 592 Practice Standard was adopted by NRCS in 2003 as another tool to assist with addressing resource concerns on livestock and poultry operations. Feed management can assist with reducing the import of nutrients to the farm and reduce the excretion of nutrients in manure.

Please check this link first if you are interested in organic or specialty dairy production

Introduction to Whole Farm Nutrient Management

Whole farm nutrient management (WFNM) includes the consideration of import of nutrients to the farm, movement and transformation (including losses) of nutrients within the farm operation, and export of milk, meat, crops, or manure.

In order to understand WFNM, it is necessary to consider all sources of nutrients, their movement within the farm, and how they might move to the environment. On most dairies, feed represents the largest import of nutrients, with fertilizer as the second largest import of nutrients. Feed Management practices currently exist to reduce imports of nutrients (particularly nitrogen and phosphorus) or decrease their excretion. Many of these specific practices and management considerations will be outlined in two assessment tools (see fact sheets- Opportunity Checklist and Feed Management Plan Checklist) as part of the implementation process of the Feed Management 592 Practice Standard.

Nutrient Utilization by the Dairy Cow

Nitrogen (N) is used for milk production in the dairy cow with an efficiency of ~ 25 to 35%. The remaining 65 to 75% of nitrogen consumed by the dairy cow remains in the initial manure (feces and urine). However, N is lost to the atmosphere via volatilization.

Phosphorus utilization by species varies from approximately 20 to 50%. The 50 to 80% not utilized is excreted in manure. A dairy cow uses approximately 27% of dietary P for milk production and thus approximately 73% of dietary P is not exported as milk from the farm.

“A dairy cow uses approximately 27% of dietary P for milk production and thus approximately 73% of dietary P is not exported as milk from the farm.”

Whole Farm Nutrient Balance

The goal of whole farm nutrient management is to achieve “zero farm balance” through the adoption of a variety of management practices, including Feed Management (see Figure 1). The practices and the relative positive or negative balance (balance = anything that remains or is left over) will be unique to each farm.

It is important to acknowledge that due to biological processes, there will be losses to the environment even when all the best management practices are adopted. Therefore, “zero balance” is difficult to achieve while maintaining high crop productivity.

The concept of Whole Farm Nutrient Balance has been described in different ways progressing from simple to more complex approaches. First, consider various approaches using nitrogen as the nutrient of interest.

1st Approach -The first approach is to estimate Mass-Balance uses the concepts of import and export of managed resources (see figure 2) at the farm boundary. This approach measures only those nutrients that cross the boundary of the farm and does not directly track nutrients flows within the farm or nutrient losses from the farm. The difference between inputs and managed outputs can be used to calculate a positive or negative balance. This positive balance represents nutrients that will be lost to the environment by both air and water pathways as well as those nutrients that accumulate on the farm (e.g. increased soil nitrogen levels). The positive balance provides an estimate of environmental risk.

2nd Approach – The second approach takes into consideration the import-export of nutrients as well as losses due to volatilization of nitrogen from manure during collection, handling, storage, and application (see figure 3). This approach would include the Mass-Balance approach, plus estimates of volatile nitrogen losses. This approach is commonly used for development of Nutrient Management Plans (NMP) and Comprehensive Nutrient Management Plans (CNMP) in many states.

3rd Approach – The third approach takes into consideration the losses of volatile nitrogen as well as leached nitrogen (see figure 4). This approach is also common to NMPs and CNMPs when leaching index tools and soil nitrogen indices are utilized in NM planning.

In contrast to nitrogen, phosphorus (P) is not lost to the atmosphere and therefore, what is not exported from the farm remains within the farmstead or possibly lost due to transport. Thus, the 1st approach (mass-balance) and 3rd approach (mass-balance plus surface and leaching loss) are the approaches that are more common for P based nutrient management planning.

Checklist Tools

The “Opportunity Checklist and Feed Management Plan Checklist” summarize the common Feed Management practices that can be adopted to assist with reducing the import of nutrients to the farm in the form of feedstuffs or reduce the excretion of nutrients in manure (see Figure 4). The opportunity checklist includes Feed Management practices or concepts that usually have the greatest initial impact. These include but are not limited to:

  1. formulation of diets to meet animal requirements,
  2. grouping animals according to nutrient needs,
  3. determining dry matter routinely and adjusting rations accordingly, and
  4. analyzing diet ingredients routinely.

Additional Feed Management practices and strategies that can further assist with reducing the importation of nutrients to the farm are outlined in the Feed Management Plan Checklist.

Spreadsheet Based Whole Farm Nutrient Management Tools

Several spreadsheet based tools are available to estimate the nutrient balance at the whole farm level. The name of these tools and where a copy can be obtained are:

  1. Whole Farm Balance Nutrient Education Tool – Washington State University
  2. Whole Farm Nutrient Balance – University of Nebraska
  3. Cornell Whole Farm Nutrient Balance Assessment Program

Summary

Whole farm nutrient management should include the consideration of import of nutrients to the farm, movement and transformation (including losses) of nutrients within the farm operation, and export of milk, meat, crops, or manure.

Whole Farm Fig 1.jpg

 

Whole Farm Fig 2.jpg

 

Whole Farm Fig 3.jpg

 

Whole Farm Fig 4.jpg

 

“Extension programs and policies are consistent with federal and state laws and regulations on nondiscrimination regarding race, sex, religion, age, color, creed, national or ethnic origin; physical, mental or sensory disability; marital status, sexual orientation, or status as a Vietnam-era or disabled veteran. Evidence of noncompliance may be reported through your local Extension office.”

Disclaimer

This fact sheet reflects the best available information on the topic as of the publication date. Date 5-30-2007

This Feed Management Education Project was funded by the USDA NRCS CIG program. Additional information can be found at Feed Management Publications.

Image:Feed mgt logo4.JPG

This project is affiliated with the Livestock and Poultry Environmental Learning Center.

Image:usda,nrcs,feed_mgt_logo.JPG

Project Information

Detailed information about training and certification in Feed Management can be obtained from Joe Harrison, Project Leader, jhharrison@wsu.edu, or Becca White, Project Manager, rawhite@wsu.edu.

Author Information

Joe Harrison
Nutrient Management Specialist
WSU-Puyallup
jhharrison@wsu.edu
253-445-4638

Rebecca White
Feed Management Educator
rawhite@wsu.edu

Partners

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A National Template for Preparing a Dairy Feed Management Plan

Printer friendly version

Introduction

This factsheet has been developed to support the implementation of the Natural Resources Conservation Service (NRCS) Feed Management 592 Practice Standard. The Feed Management 592 Practice Standard was adopted by NRCS in 2003 as another tool to assist with addressing resource concerns on livestock and poultry operations. Feed management can assist with reducing the import of nutrients to the farm and reduce the excretion of nutrients in manure.

The Feed Management 592 Practice Standard adopted by NRCS is defined as “managing the quantity of available nutrients fed to livestock and poultry for their intended purpose.” The national version of the practice standard can be found in a companion factsheet entitled An Introduction to Natural Resources Conservation Service (NRCS) Feed Management Practice Standard 592. Please check your state-specific version of the standard.

The national Feed Management Education Team has developed a systematic five-step development and implementation process for the Feed Management Practice Standard. A complete description of the five steps can be found in a companion factsheet entitled Five Steps to the Development and Implementation of a Feed Management Plan.

The fourth step of this process focuses on the development of the Feed Management Plan. Key participants at Step 4 are the producer and his nutritionist. The key tools to be used at Step 4 are the Feed Management Plan (FMP)Checklist and the Feed Management Plan Template.

Please check this link first if you are interested in organic or specialty dairy production

Using the Feed Management Plan Template

The Feed Management Plan, or FMP, is intended to assist the producer with documentation of those practices that affect whole-farm nutrient management and contribute toward achieving nutrient balance at a whole-farm level. Nitrogen and phosphorus are the two nutrients that are required to be managed as part of the FMP in a Comprehensive Nutrient Management Plan.

When nitrogen and phosphorus imports exceed nitrogen and phosphorus exports, there is an imbalance at a whole-farm level. These imbalances can lead to impaired water quality in nearby water bodies due to both surface runoff and leaching of nutrients to groundwater. Excess nitrogen can also be volatilized and contribute to impaired air quality. Potassium is a nutrient that can lead to production and health problems if it is not monitored in dairy rations, therefore, it is also included as a nutrient to monitor.

The FMP template is designed to provide a common format to address all areas noted in the Feed Management 592 Practice Standard. It is organized with the following sections:

  • Contact information
  • General purpose and background information about the 592 standard
  • Specific purpose selection for the operation
  • When the plan was written
  • When the plan will be reviewed
  • Specific farm information for use with the electronic manure excretion estimator tool
  • Summary of feeding practices and equipment/technologies utilized on the farm
  • Record keeping
  • Recommendations

Estimate of Manure Nutrient Excretion

As part of the FMP, the impact that feed management will have on manure volume and nutrient content is estimated. The specific farm information section has been included to collect farm-specific descriptive information for use with the electronic manure excretion estimator tool. This tool is described in a companion factsheet entitled Estimating Manure Nutrient Excretion.

Feed Management Practices

This section should include a list and narrative of those practices that have been adopted. One way to document practices is to insert a copy of the completed Feed Management Plan Checklist. Proprietary information or specific ration formulations need not be included.

Guidance Sections

There are two important sections of the FMP that should contain specific guidance about sampling and analysis procedures, these are:

  • Record of feed sampling and feed analysis
  • Final recommendations

By following this link you will find a blank copy of the Feed Management Plan Template (PDF file). Additionally, a Completed Feed Management Plan (PDF file) is available as an example.

Related Files

To follow the references in this article, it is recommended that you print these PDF files and refer to them at the appropriate places.
Feed Management Plan Template
Example Feed Management Plan (Dairy).

Disclaimer

This factsheet reflects the best available information on the topic as of the publication date. Date 5-25-2007

This Feed Management Education Project was funded by the USDA NRCS CIG program. Additional information can be found at Feed Management Publications.

Image:Feed mgt logo4.JPG

This project is affiliated with the Livestock and Poultry Environmental Learning Center.

Image:usda,nrcs,feed_mgt_logo.JPG

Project Information

Detailed information about training and certification in Feed Management can be obtained from Joe Harrison, project leader, jhharrison@wsu.edu, or Becca White, project manager, rawhite@wsu.edu.

Author Information

Joe Harrison, Becca White, Lynn Johnson-VanWieringen, and Ron Kincaid, Washington State University
Mike Gamroth, Oregon State University
Tamilee Nennich, Texas A&M University
Deb Wilks, Standard Nutrition

Partners

Logos2.JPG

 

Acknowledgments

This Feed Management Education Project was funded by the USDA NRCS CIG program. Additional information can be found at Feed Management Publications.
This project is affiliated with the Livestock and Poultry Environmental Learning Center

usda,nrcs,feed_mgt_logo.JPG

 

“Extension programs and policies are consistent with federal and state laws and regulations on nondiscrimination regarding race, sex, religion, age, color, creed, national or ethnic origin; physical, mental or sensory disability; marital status, sexual orientation, or status as a Vietnam-era or disabled veteran. Evidence of noncompliance may be reported through your local Extension office.”

Estimating Manure Nutrient Excretion

Printer friendly version

Introduction

This fact sheet has been developed to support the implementation of the Natural Resources Conservation Service Feed Management 592 Practice Standard. The Feed Management 592 Practice Standard was adopted by NRCS in 2003 as another tool to assist with addressing resource concerns on livestock and poultry operations. Feed management can assist with reducing the import of nutrients to the farm and reduce the excretion of nutrients in manure.

The Natural Resources Conservation Service has adopted a practice standard called Feed Management (592) and is defined as “managing the quantity of available nutrients fed to livestock and poultry for their intended purpose”. The national version of the practice standard can be found in a companion fact sheet entitled “An Introduction to Natural Resources Feed Management Practice Standard 592”. Please check in your own state for a state-specific version of the standard.

Please check this link first if you are interested in organic or specialty dairy production

Estimating Manure Nutrient Excretion

The front and back end of an animal is connected. While this principle seems obvious, it has historically been ignored in nutrient planning procedures. This fact sheet describes tools that allow integration of feed management and animal performance into nutrient planning processes for animal feeding operations.

A new standard published by the American Society of Agricultural and Biological Engineers (D384.2, Manure Production and Characteristics) is a tool for developing farm specific Comprehensive Nutrient Management Plans (CNMP). This standard allows accurate estimates of nutrient and solids excretion reflective of feed programs and animal performance. Accurate estimates of manure excretion are critical to estimating land requirements and land application costs, sizing manure storage, and planning treatment technologies. This fact sheet will introduce the new manure excretion standard and its application.

Contents of the Manure Production Standard

An ASABE committee of animal scientists and agricultural engineers developed predictive equations for estimating manure excretion for five species (beef, dairy, horse, poultry, and swine) and “typical” characteristics for excreted and as-removed manure. The standard is found at ASABEfollowed by a search of “Standards” and “Title” options for “Manure Production”. The ASABE standard includes seven sections.

Section 1 lists a new “typical” characteristics tabular summary for individual species and groupings of animals. See Tables 1 and 2.(PDF file) These values should provide a reasonable estimate of excretion for animals in the year 2000. As time passes, published typical values become less accurate and should be used with caution for individual herds or flocks. Differences in genetics, feed program, and animal performance between individual farms create a potential for errors when typical values are applied. They may have value for preliminary nutrient planning estimates but should NOT be used in final farm-specific nutrient management plans.

Sections 2 through 7 define the equations for cattle, dairy cattle, horses, poultry (separate sections for meat birds and layers), and swine, respectively. Equation based estimates are provided for all species groups for dry matter, N and P excretion. Equations for estimating additional characteristics are available for some species.

Section 8 of the new standard summarizes As-Removed manure characteristics. The work group summarized a wide range of data sets for inclusion in this section. These values can be beneficial for estimating storage volumes and manure application rates when no other farm-specific information is available. However, when farm specific manure samples are available, they are preferred.

Two Approaches for Estimating Excretion

Two distinctly different approaches were used equation based estimates of excretion. The beef, swine, and poultry work groups used an animal mass balance approach (Figure 1). Excretion is estimated as a difference between feed nutrient intake and retention in body mass or animal products (eggs or milk). intake and retention in body mass or animal products (eggs or milk). The dairy and horse work groups used existing data sets as a basis for multi-variable regression analysis. The dairy work group proposed equations for lactating cows, dry cows and heifers. The horse work group chose to publish separate equations for exercised and sedentary horses. See Table 1. Estimated typical manure (urine and feces combined) characteristics as excreted by meat-producing livestock and poultry.(PDF file) Diet based numbers are in BOLD. Source ASAE D384.2 March 2005, Manure Production and Characteristics.

Figure 1. Mass balance approach was used for estimating excretion haracteristics for beef cattle, swine and poultry.

Factors Affecting Nutrient Excretion

The new standard defines the relationship between feed inputs and animal performance and manure excretion characteristics. For example, the quantity of solids excreted is directly tied to the dry matter digestibility of the diet. Since dry matter digestibility for many species is often 80 to 85% (15 to 20% of solids in feed excreted in feces), small changes in dry matter digestibility produce large differences in solids excreted. A dietary modification that changes dry matter digestibility change from 85% to 80% results in 33% more solids in the feces. Similarly, dietary intake of protein and phosphorus is directly related to excreted N and P.

Historically, manure excretion estimates have been based upon standards published by the ASABE, USDA Natural Resources Conservation Service, and Midwest Plan Service. These previous standards varied excretion estimates with species and animal weight only. A linear relationship was assumed between excretion and body weight. However, this approach provides a poor explanation of important biological factors that influence manure excretion. In addition, these standards become dated with time because they do not recognize changes in genetics, animal performance, and feeding options. Current and past excretion estimates based upon species and body weight alone often produce inaccurate estimates of manure excretion for individual farms.

The standard for manure excretion released by ASABE in 2005 was designed to provide farm-specific estimates of excretion reflective of individual farm feed programs and animal performance. In addition, this standard will better adapt to changes in excretion that occur over time due to factors such as improved animal genetics. Thus, the equation based standard for manure excretion released in 2005 should remain accurate well into the future.

Is This Important?

Tables 3, 4, and 5(PDF file) illustrate excretion estimates for beef, swine, and dairy calculated from the new equations. Some of the more dramatic differences between the current ASABE and other standards are associated with P and total solids excretion. These differences tend to become larger as emerging feed technologies reduce nutrient excretion and as feeding of by-products of corn processing and other food processing industries become increasingly popular. To illustrate the importance of the new ASABE standard for farm specific estimates, comparisons are illustrated below for three species.

Beef

A comparison of excretion characteristics estimated by the new ASABE standard with past standards (Table 3, Rows A-C) suggests that previous estimates are in reasonable agreement for N excretion but in poor agreement with P excretion. A significant effort to better match beef cattle rations with phosphorus requirements has reduced P excretion substantially.

Considerable variation exists between individual cattle feedlots relative to performance and feed program strategies. Substantial variation in N and P excretion is anticipated when comparing a corn based ration (Table 3, Row C) and a ration with 40% distillers grains (Table 3, Row D). Combining feed program variation with typical ranges in animal performance can produce a 2-fold range in N excretion and a 3-fold range in P excretion (Table 3, Rows F and G). Large errors in beef cattle excretion estimates are common unless performance and feed program are considered in estimating excretion.

Swine

Typical nitrogen excretion estimates for swine for the new standard have changed little from the past ASAE standard (Table 4, Rows A-B). However, phosphorus excretion is substantially lower than other standards. Total solids excretion is also generally lower than previously accepted values.

Table 4 illustrates the importance of a standard that responds to emerging feeding strategies (Table 4, Row C). Diets based on use of crystalline amino acids and phytase have the potential for lowering dietary CP and P levels and N and P excretion. A low CP diet would produce N excretion levels up to 40% less than new standard typical value. Low P diets would reduce P excretions levels by 33 to 40% from new typical values.

Dairy Cattle

Generally the new ASABE standard predicts greater excretion of nutrients and solids as compared to the past ASAE standard and other existing accepted values for lactating cattle (Table 5, Rows A and B. Steadily increasing milk production will create an even larger disparity between predicted excretion by the new ASABE standard and other past values.

Tools for Applying ASABE Standard

The proposed ASABE equations complicate the process of estimating nutrient and solid excretion. Software tools based upon these equations provides one option for improving the utility of equations and their application to farm specific CNMPs. Two spreadsheet tools use the ASABE estimate of excreted nutrients as a basis for estimating land requirements for managing manure nutrients. A Nutrient Inventory comes with instructions and a one-hour video discussing its application (available at University of Nebraska). A second tool nearing completion (FNMP$) will estimate land requirements, cost and time required for land applying manure, and potential economic benefits of manure nutrients (will be available at the same web site).

A simplified hand calculator of nutrient excretion was introduced in a MWPS publication, Manure Characteristics (Table 6). It uses a mass nutrient balance procedure for estimating excretion for beef, dairy, poultry and swine. It provides a simplified approach that produces similar answers to procedures used in the ASABE standard.

Information Requirements for Using New Standard

The information requirements of the new standard are greater than with past standards. Farm specific information is needed for animal performance ( e.g. weight gain or milk production) and feed program (dry matter intake and nutrient concentration). Those input requirements are summarized in [media:Table7excretion.pdf | Table 7]].

Applications of New ASABE Standard

Most nutrient planning processes follow a step-wise procedure similar to that illustrated in Figure 2. At this time, the equation-based estimates of solids and nutrients will have their greatest utility in the strategic or long-term planning. These strategic plans are of greatest value to a new or expanded facility or when a regulatory permit is being assembled.

Figure 2 illustrates a second critical planning phase, the Tactical or Annual Plan. For decisions such as manure application rates, timing, and location, constantly changing conditions such as weather and residual soil nutrients must be considered. On-farm data such as manure samples will likely be of greater value to annual planning processes than the predictions made by the new ASABE equations

Figure 2. Common planning procedure used for nutrient management planning.

Improvements in nutrient excretion estimates offered by the new equations should improve the accuracy of farm-specific planning for:

  • Land requirements for managing N and P. The equations provide a more accurate estimate of nutrient driven land requirements for manure application when on-farm data on manure production is not available. Nitrogen volatilization and availability estimates remain a weak point for this planning process.
  • Cost of manure application. The ASABE equations are being used to estimate manure nutrient value as well as time, equipment, and labor requirements for handling manure (Kissinger et al., 2005).
  • Ammonia emissions. Ammonia emissions from animal facilities are of increasingly interest to the regulatory community. The equations should provide a mechanism for adjusting farm emission estimates based upon several farm-specific factors.

The equations also allow a prediction of dry matter excretion and possibly volatile solids excretion if feed digestibility values are known. This approach will allow farm specific estimates of solids excretion that will benefit planning estimates of:

  • Anaerobic and aerobic lagoon sizing,
  • Anaerobic digester sizing and gas production,
  • Storage sizing if solids estimates are combined with known moisture contents resulting from specific manure handling systems

Summary

The new ASABE standard for manure excretion provides an important tool for key strategic planning activities important to a comprehensive nutrient management plans. In addition, the new standard provides an important tool for integrating feed management decisions into CNMPs and deciding the environmental and economic benefits and costs of feed program options.

Related Files

To follow the references in this article, it is recommended that you print these four PDF files and refer to them at the appropriate places in the article.
Tables 1 and 2
Tables 3, 4 and 5
Table 6
Table 7

Disclaimer

This fact sheet reflects the best available information on the topic as of the publication date. Date 5-25-2007

Acknowledgements

This Feed Management Education Project was funded by the USDA NRCS CIG program. Additional information can be found at Feed Management Publications.

Image:Feed mgt logo4.JPG This project is affiliated with the Livestock and Poultry Environmental Learning Center.

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Project Information

Detailed information about training and certification in Feed Management can be obtained from Joe Harrison, Project Leader, jhharrison@wsu.edu, or Becca White, Project Manager, rawhite@wsu.edu.

Author Information

R.K. Koelsch, University of Nebraska-Lincoln

Images: CC 2.5 Rick Koelsch

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“Extension programs and policies are consistent with federal and state laws and regulations on nondiscrimination regarding race, sex, religion, age, color, creed, national or ethnic origin; physical, mental or sensory disability; marital status, sexual orientation, or status as a Vietnam-era or disabled veteran. Evidence of noncompliance may be reported through your local Extension office.”

NRC Recommendations for Dairy Cows

Introduction

This fact sheet has been developed to support the implementation of the Natural Resources Conservation Service Feed Management 592 Practice Standard. The Feed Management 592 Practice Standard was adopted by NRCS in 2003 as another tool to assist with addressing resource concerns on livestock and poultry operations. Feed management can assist with reducing the import of nutrients to the farm and reduce the excretion of nutrients in manure.

Please check this link first if you are interested in organic or specialty dairy production

Feed Management

Feed Management is one of six components in a Comprehensive Nutrient Management Plan (CNMP). Feeds represent a costly fraction on a dairy farm budget and feed inputs are among the largest sources of nutrients imported to the operation. Feed management depends on adequate feed acquisition and allocation, in quantity and quality sufficient to supply the herd’s nutrient demands for a given period of time. Knowledge of animal nutrient requirements is paramount for a successful Feed Management.

Nutrient requirement standards for most economically important farm animal species have been reported by the National Research Council (NRC) since the early 20th century . NRC’s seventh revised edition of the Nutrient Requirements of Dairy Cattle, issued in 2001, included significant alterations over its previous edition (1989). Calculations of nutrient requirements and their interactions are integrated by the 2001 Dairy NRC in a computer model that allows for estimates of nutrient requirements and dynamic ration evaluation.

Better comprehension of the processes used to determine a dairy cow’s nutrient requirements in the NRC (2001) model is essential for the success of the nutrient management plan. A few aspects of nutrients that are relevant to Nutrient Management (nitrogen, phosphorus, and potassium) are discussed below. For more detailed information, please refer to the publication indicated above.

Nutrients

Nitrogen (Protein)

Two aspects must be considered to evaluate a ration’s adequacy: the nutrients supplied by the diet (nutrients contained in feeds) and the cows’ nutrient demand for body maintenance, reproduction, production and growth in cows that have not reached mature body weight.

Protein content in feedstuffs is usually referred to as crude protein (CP). In the laboratory, feed samples are actually analyzed for nitrogen (N) content, and CP is calculated as:

CP = N × 6.25

This equation is based on the assumption that dietary protein contains an average of 16% N.

“Nitrogen is of primary environmental concern because of losses of ammonia in the air and because of nitrate contamination of surface water and groundwater.” NRC (2001)

In the 2001 dairy NRC, feed protein supply is divided into two fractions: rumen degraded protein (RDP) and rumen undegraded protein (RUP). Rumen degraded protein supplies microbial needs. However, rumen microbes require non-protein N (ammonia, amino acids, peptides,) as “building blocks” of microbial protein (MCP). The extent of MCP synthesis in the rumen depends on a number of factors including level of feed intake, digestion rate (Kd) of diet components in the rumen, and passage rate (Kp) of digesta from the rumen. In the absence of a more reliable analytical method, the NRC subcommittee chose to use three fractions (A, B, C) derived indirectly from rumen incubation of in situ bags to derive RDP and RUP supplied by feed ingredients (kg/d):

RDP = A + B × [Kd/(Kd + Kp)]

RUP = B × [Kp/(Kd + Kp)] + C

Where A is the amount (kg/d) of N presumably readily available to microbes, B is the amount of N that is available by degradation (at a rate = Kd) and C is the amount of N unavailable for microbial growth.

Ruminants also recycle N to the rumen as salivary urea that can be used by rumen microbes, especially when dietary N is below optimal. That N source, along with enzymes and sloughed cells released in the gut are called endogenous CP because they come from within the body of the cow.

Finally, three sources of protein leave the cow’s stomachs and reach the small intestine:
MCP;
RUP; and
Endogenous CP.

Digestible protein will be hydrolyzed in the small intestine essentially into amino acids, which can be absorbed and used for body maintenance, growth, reproduction, and lactation. The absorbable amino acids, defined in NRC (2001) as metabolizable protein (MP), can be converted into milk protein with an average efficiency of 67%. Considering an average intestinal digestibility of 0.65, one can estimate the theoretical maximum milk N efficiency of utilization as:

0.67 × 0.65 = 0.44 or 44 %

After more than half a decade of its publication, the NRC (2001) protein requirement model withstood a number of comparisons and validations against measured data and other models. Some criticism has been observed. Those include the need for accurate feedstuff characterization, extent and complexity of inputs required by the model, overestimation of RDP requirements because nitrogen recycling is not taken into consideration, over-prediction of milk response to RUP supplementation, and over-evaluated energy value of proteins. However, if default values are replaced by more accurate feed and animal characterization, the NRC (2001) model has accurately predicted milk and protein production.

Finally, because the NRC (2001) is a dynamic model that incorporates animal-feed interactions, and feed-feed interactions. Thus, the computer model should be used rather than the tabulated values. In general, the NRC (2001) predicts that dietary CP contents between 16.5 and 17.5 % of the DM supply the protein requirements of early-lactation dairy cows under most conditions. Dietary CP should be equal to or below 16.5% as cows advance into the second half of the lactation.

Phosphorus

In the NRC (2001), phosphorus (P) in feed and microbes were given absorption coefficients (AC).

“Of all dietary essential mineral elements for dairy animals, phosphorus represents the greatest potential risk if excess is released into the environment contaminating surface waters and causing eutrophication.” NRC (2001)

Phosphorus AC is the efficiency with which P from a source is absorbed in the cow’s small intestine. The AC is variable, depending on a number of animal and feed characteristics. For instance, decreasing P content of the diet increases the AC and P efficiency of utilization from feed to milk. The NRC (2001) adopted fixed absorption coefficients for forages (0.64) and concentrates (0.70). Only mineral sources were given specific ACs. For instance, dicalcium phosphate AC is 0.75, while higher ACs were applied to monosodium phosphate and phosphoric acid (0.90). Those AC values were higher than the 0.50 value used previously (NRC, 1989). Endogenous P sources, a major recycling route in ruminants, have an AC above 0.70.

Phosphorus available for absorption is defined as absorbable P and is calculated as feed P (in grams) multiplied by its AC and summed for all feeds in the diet:

Absorbable P = ∑(feed P × feed P AC)

The NRC (2001) estimates dairy cows’ demand for absorbed P based on a factorial approach. The factorial determination of requirements accounts for the absorbed P necessary for maintenance, growth, reproduction and lactation.

Milk P averages at 0.090%, but may range from 0.083% to 0.100%. Given the milk volume produced by modern dairy cows, milk P makes up for the largest proportion of the requirements for a lactating dairy cow, followed by body maintenance, and only a small fraction needed for growth and reproduction. Phosphorus demand for fetal growth is relevant only in the last third of gestation.

Phosphorus supply adequacy is estimated as dietary absorbable P minus the sum of requirements (maintenance + growth + reproduction + lactation).

Current NRC P recommendations for lactating dairy cows range from 0.30 to 0.40 % of the diet DM, depending particularly on milk production. A number of studies have shown no production or reproduction benefits from feeding P above NRC dietary recommendations, and that most excess P is excreted in feces.

Using dicalcium phosphate ($400/ton = $0.82/lb P, discounted Ca value), one can estimate that it costs $1.50/cow/year for every one hundredth of a percentage unit (0.01) P increased above NRC recommended level for a cow eating 50 lb/d of dry matter. Overfeeding P to lactating dairy cows is uneconomical, wasteful and may harm the environment.

Potassium

The NRC subcommittee adopted a single AC of 0.90 for potassium (K) in all feeds. Potassium requirements are calculated similarly to P requirements.

Lactating dairy cows have high demand for K. As much as an ounce of K will be secreted with every 42 lbs of milk, but even larger quantities are lost with sweat, feces and particularly in urine. Those requirements must be supplied on a daily basis because K is not stored in the body.

Despite recognition that the requirement increases with higher temperatures (sweating), NRC (2001) K model does not take into consideration ambient temperature to calculate K requirements. Furthermore, K is an important element influencing the DCAD (Dietary Cation-Anion Difference) of a ration (in addition to sodium (Na) and chloride (Cl)). There has been increased interest in how DCAD affects acid-base balance of dairy cows. Whereas a low DCAD (in general lower dietary K and Na, high Cl) has been recommended for periparturient cows to prevent milk fever, higher postpartum DCAD (~+200 meq/kg) is suggested to maximize milk production. This dichotomy raises concerns and complicates K balance in a nutrient management plan.

NRC (2001) recommended dietary K levels ranging from 1.0 to 1.2% of the dry matter.

“Application of manures of fertilizers rich in potassium to crop land can result in excess potassium in the environment and very high potassium content of forages. This can cause problems with calcium and magnesium metabolism particularly for periparturient cows, and may cause udder edema.” NRC (2001)

Table 1. Nutrient requirements of lactating dairy cows estimated with the NRC (2001) model using sample diets varying feeds, stages of the lactation and milk production levels.1
Scenario 1 Scenario 2 Scenario 3 Scenario 4 Scenario 5
Animal description:
Age, months 52 55 53 55 59
Parity 3 3 3 3 3
Body weight, lb 1432 1432 1432 1432 1432
Body weight change, lb/d -0.88 0.00 -1.10 -1.10 1.50
Days in milk 45 120 60 120 250
Days pregnant 0 50 0 50 170
Body condition score 2.75 2.75 2.75 2.75 3.50
Production inputs:
Milk production, lb/d 98.0 98.0 130 130 45.0
Milk fat, % 3.50 3.50 3.50 3.50 3.70
Milk true protein, % 3.00 3.00 3.00 3.00 3.00
Milk lactose, % 4.78 4.78 4.78 4.78 4.78
Intake estimated by NRC (2001) model:
Dry matter intake, lb/d 51.8 59.5 64.7 70.3 42.7
Sample diet used in the NRC (2001) model, lb dry matter/d:
Corn silage, normal 23.50 28.20 24.07 32.00 19.40
Legume forage hay, mid-mat. 4.25 7.25 8.41 5.48 6.60
Bermudagrass hay, Tifton-85 2.38 4.40
Grass hay, C-3, mid-mat. 1.98 2.69 6.60
Whole cottonseed 4.54
Soybean, meal, solv. 48% CP 6.72 6.41 3.68 9.49 0.46
Soybean, meal, expellers 2.33 1.01 1.83
Corn gluten meal 4.21
Urea 0.18
Corn grain, steam-flaked 4.10
Corn grain, ground, hi moist. 10.37 17.80 15.46
Corn grain, ground, dry 12.78
Tallow 0.99 1.37
Calcium soaps of fatty acids 0.26 0.26 0.35
Calcium carbonate 0.20 0.20 0.29 0.22 0.10
Monosodium phosphate (1 H2O) 0.11 0.09 0.18 0.15 0.04
Salt 0.30 0.29 0.32 0.25 0.20
Vitamin and mineral premix 0.77 0.90 0.95 1.00 0.62
Diet nutrient contents:
% RDP 10.2 9.7 9.7 9.6 9.6
% RUP 6.9 6.1 7.8 7 3.8
% CP(%RDP + %RUP) 17.1 15.8 17.5 16.6 13.4
% phosphorus (P) 0.38 0.36 0.40 0.38 0.29
% potassium (K) 1.32 1.31 1.13 1.29 1.46
1Feeds were chosen from NRC (2001) feed library for example purposes. For accurate diet evaluation, the NRC (2001) model requires animal description and feed analyses for every specific situation.

References

National Research Council. 1989. Nutrient Requirements of Dairy Cattle. 6th rev. ed. Natl. Acad. Sci., Washington, D.C.

National Research Council. 2001. Nutrient Requirements of Dairy Cattle. 7th rev. ed. Natl. Acad. Sci., Washington, D.C.

“Extension programs and policies are consistent with federal and state laws and regulations on nondiscrimination regarding race, sex, religion, age, color, creed, national or ethnic origin; physical, mental or sensory disability; marital status, sexual orientation, or status as a Vietnam-era or disabled veteran. Evidence of noncompliance may be reported through your local Extension office.”

Disclaimer

This fact sheet reflects the best available information on the topic as of the publication date. Date 10-15-2006

This Feed Management Education Project was funded by the USDA NRCS CIG program. Additional information can be found at Feed Management Publications.

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This project is affiliated with the LPE Learning Center.

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Project Information

Detailed information about training and certification in Feed Management can be obtained from Joe Harrison, Project Leader, jhharrison@wsu.edu, or Becca White, Project Manager, rawhite@wsu.edu.

Author Information

Vinicius Moreira
LSU AgCenter Southeast Research Station
VMoreira@agcenter.lsu.edu

Reviewer Information

Fred Moore – EPA Region 6 Liason
Michael Wattiaux – University of Wisconsin

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