ACCURATELY ESTIMATING COW-LEVEL DIGESTION: WHERE DO DIGESTION RATES FIT AND WHAT DO THEY MEAN?

Transcription

1 ACCURATELY ESTIMATING COW-LEVEL DIGESTION: WHERE DO DIGESTION RATES FIT AND WHAT DO THEY MEAN? 2014 Formuleite Conference Dr. John Goeser, PAS Animal Nutrition and R&I Director Rock River Lab, Inc. Adjunct Asst. Professor University of WI Madison, Dairy Science

2 Agenda: 90 Min. Brazil Industry Outlook? Nutrition/Ration program aim & utility Where do digestion measures fit? Practical digestion measure background How can we improve performance? What do the cows have to say? The next 15 years

3 Brazil Dairy Industry Outlook? Quickly growing industry Demand for knowledge and performance Adopting technology and guidance with rapid pace Education level rapidly increasing Profit Margin Focus Image Source: catracalivre.com.br

4 Nutrients and Nutrition Nutrients are those that furnish nourishment (Miriam-Webster, 2014 accessed online) CP, carbohydrates and fat are nutrients 9.4, 4.2 and 5.6 calories per g, respectively (NRC, 2001) Calories make milk NDF = Starch???? Image source: crossfitrebels.com

5 Nutrition Program Aim Energy (calories) can be considered a nutrient How do we get there? Nutrient % (CP, NDF, etc) Nutrient Digestibilities (NDFD, etc) Total Digestible Nutrients, TDN ME or NE L Weiss, 1998 Weiss, 1998

6 Assessing feedstuff digestion: Evolution Practical approaches Late 1800 s Proximate Feed Analysis system Later the Detergent System for analyses (Goering & Van Soest, 1970) NDF, ADF and lignin Rumen and intestinal digestion estimates Long term aim Improve rumen, intestine and ultimately total tract digestion and program ME/MP predictions

7 CHO Digestion impact on milk New Crop corn silage and HMSC? 10 unit less diet rumen starch digestion 5 kg. less milk (e.g vs kg/cow) 150 g less microbial CP Substantial change in new crop CS/Hlg NDFD? 10 unit change in diet TTNDFD 5 kg. less milk (e.g vs kg/cow) 127 g less microbial CP Estimated with modified NRC (1989; 2001) equations to incorporate nutrient k d and pool sizes How do we better forecast these responses? Milk image source:

8 Nutritional composition of corn silage produced in Parana Mínimo Média Máximo EUA MS CNF Amido FDN kd do FDN, %/hr 2,7 3,2 3,8 3,7 TTNDFD, % Dig FDN 24 hrs, % Dig FDN 30 hrs, % Dig FDN 48 hrs, %

9 Nutritional composition of corn silage produced in Minas Gerais Mínimo Média Máximo EUA MS CNF Amido FDN kd do FDN, %/hr 2,2 3,4 4,5 3,9 TTNDFD, % Dig FDN 24 hrs, % Dig FDN 30 hrs, % Dig FDN 48 hrs, %

10 Digestion Coefficients Challenging aspect to ruminant nutrition Which NDFD or Starch D rumen time point?!?

11 Factors Affecting Digestion Seed / genetics Crop management Growing environment Fermentation / preservation Crop / feed processing Rumen dynamics Interactions with other ingredients Passage rate Dry matter intake Production level / stage Body size Forage to Concentrate ratio Etc

12 Using digestion measures Dictionary First Terminology Digestion coefficient (e.g. NDFD or StarchD) = % of nutrient that is digested This is the end result value used within ration programs to calculate TDN1x, microbial CP and energy available for performance There are two basic ways to determine digestion coefficients Direct measurement (e.g. in vitro, in situ or in vivo measures) Calculate using pool size, digestion and passage rates k = rate coefficient Corresponding to a nutrient or passage disappearing at a certain % per h k d = digestion rate coefficient (e.g. NDF k d or Starch k d ) k d rate is often used in the field to describe digestion rate; however this is redundant, and incorrect terminology k p = passage rate coefficient (e.g. liquid or forage) Pool size = nutrient amount (% total nutrient) available to the specified degradation and passage rate

13 Where does nutrient k d fit? Nutrient % (CP, NDF, etc) Nutrient Digestibilities (NDFD, etc) Total Digestible Nutrients, TDN ME or NE L

14 Think of k d & dig. Nutrient Pool size like fuel economy (Combs, pers. comm.)

15 Rumen Works the Same! Same NDF k d (fuel economy) Different digestible Pool sizes (tank).3 liters performance! Different NDF k d (fuel economy) Same digestible Pool sizes (tank) Also 3 liters performance!

16 How can we practically estimate k d and pool size? 1. Lab bench rumen and intestinal in vitro Meaning outside the body (Miriam-Webster, 2014) 2. Rumen or intestinal incubation rumen/intestinal in situ Meaning in the natural or original position (Miriam- Webster, 2014) 3. Through the animal in vivo Meaning in the living body (Miriam-Webster, 2014)

17 Diet forecast starts with a practical digestion measure

18 Rumen or intestinal in vitro digestion

19 Rumen/Intestinal in vitro digestion Advantages Fast and flexible Many measures over time Sample completely contained Cost effective Assess individual feedstuffs & nutrients Challenges Inaccuracy due to complete removal from animal Isolated from real rumen interactions Inoculum consistency Poor repeatability Reduced particle size (1 to 4 mm)

20 Rumen in situ digestion

21 Rumen/Intestinal in situ digestion Advantages Flexible Many measures over time, k d Feeds exposed to real lactating cow rumen environment Assess multiple nutrients per sample Challenges Increased cost Need for lactating, cannulated animals Samples not subject to true passage rates Poor repeatability across labs Sample disappearance from bag

22 Cow level in vivo digestion

23 Cow level in vivo digestion Advantages Assess true diet performance Total tract measures for practical purposes Paramount accuracy without substantial assumptions Challenges Only the TMR can be assessed Costly and time consuming Sample both TMR and feces Complex interpretation

24 Now what? How do we use digestion results within ration models? Can we improve ration performance? What do the cows have to say?

25 Formulating with CHO Digestion results Two core theories Empirical: NRC (2001) Biology or similar Old Book values Recent - 48 h in vitro digestion and other regression values Future??? Mechanistic: CPM, CNCPS Biology or similar Old Book CHO k d and pool size values More recent Lab measured CHO k d and pool sizes Future??? The next 15 years?

26 What do Cows have to say? Meta-Analyses summary from those reporting in vivo digestion results for lactating cattle (Goeser, 2014) Description Nutrient Animal Type Digestion Site Author(s) Treatment Digestion means Coefficient, % SD Mixed TMRs NDF Lactating Dairy Cow Rumen Firkins et al. (2001) Mixed TMRs NDF Mixed Rumen Hannigan et al. (2013) Corn silage based TMRs NDF Lactating Dairy Cow Rumen Ferraretto and Shaver (2012) NA TMRs containing barley based grain NDF Lactating Dairy Cow Rumen Ferraretto et al. (2013) NA TMRs containing corn based grain NDF Lactating Dairy Cow Rumen Ferraretto et al. (2013) NA n or Weighted means NDF Rumen Alfalfa and Grass Forage based TMRs NDF Lactating Dairy Cow Total Tract Goeser (2008) Corn and Sorghum Forage based TMRs NDF Lactating Dairy Cow Total Tract Goeser and Combs (unpublished) Mixed TMRs NDF Lactating Dairy Cow Total Tract Firkins et al. (2001) Mixed TMRs NDF Mixed Total Tract Hannigan et al. (2013) TMRs NDF Mixed Total Tract Krizsan et al. (2010) Corn silage based TMRs NDF Lactating Dairy Cow Total Tract Ferraretto and Shaver (2012) NA TMRs containing barley based grain NDF Lactating Dairy Cow Total Tract Ferraretto et al. (2013) NA TMRs containing corn based grain NDF Lactating Dairy Cow Total Tract Ferraretto et al. (2013) NA n or Weighted means NDF Total Tract Mixed TMRs Starch Lactating Dairy Cow Rumen Firkins et al. (2001) Mixed TMRs Starch Mixed Rumen Hannigan et al. (2013) Corn silage based TMRs Starch Lactating Dairy Cow Rumen Ferraretto and Shaver (2012) NA TMRs containing corn based grain Starch Lactating Dairy Cow Rumen Ferraretto et al. (2013) NA TMRs containing barley based grain Starch Lactating Dairy Cow Rumen Ferraretto et al. (2013) NA n or Weighted means Starch Rumen Mixed TMRs Starch Lactating Dairy Cow Total Tract Firkins et al. (2001) Mixed TMRs Starch Mixed Total Tract Hannigan et al. (2013) Corn silage based TMRs Starch Lactating Dairy Cow Total Tract Ferraretto and Shaver (2012) NA TMRs containing barley based grain Starch Lactating Dairy Cow Total Tract Ferraretto et al. (2013) NA TMRs containing corn based grain Starch Lactating Dairy Cow Total Tract Ferraretto et al. (2013) NA n or Weighted means Starch Total Tract

27 What do Cows have to say? TMR - Fiber - Starch Rumen in vivo NDF = 42.0 ± 24 Starch = 59.3 ± 31 Total Tract in vivo NDF = 48.5 ± 22 Starch = 92.4 ± 6.5

28 How accurate are we NDFD? Rumen NDFD (30 h) = TMR reality based on in vivo meta-analysis = Legume traditional in vitro = Corn silage traditional in vitro Rumen NDF Digestion, % of Nutrient

29 More Accurate NDFD Approach? TTNDFD (Combs, 2013) Feed Type Preservation TTNDFD (% of NDF) Legume Hay 39.3 Legume Silage 41.5 Mixed Forage Hay 40.5 Mixed Forage Silage 43.0 Grass Hay 42.5 Grass Silage 45.9 Corn Silage Silage 43.6 Sorghum/Sudan Silage 48.1 Small Grains Hay 42.7 Small Grains Silage 43.3 Realistic Min and Max 25 to 65

30 TTNDFD further Validated TTNDFD and associated model inputs are related to dairy cattle digestion measures Lopes et al. (2014) and Goeser et al. (2014) separately validated TTNDFD measures against total tract in vivo measures Lopes et al.: in vivo TTNDFD = *in vitro TTNDFD Slope P < 0.001, R 2 = 0.61 Goeser et al.: in vivo TTNDFD = *in vitro TTNDFD Slope P < 0.01, R 2 = 0.30 Adapted from Goeser et al. (2014)

31 How accurate are we Starch D? Rumen Starch D results summary = TMR reality based on in vivo meta-analysis = predicted using k d from 7 h in situ data = predicted using k d from 7 h in vitro data Rumen Starch Digestion, % of Nutrient

32 What Are Real Rumen 7 h Starch D Values? Opportunities? Estimates based on rumen potentially digestible starch values from meta-analysis dataset and assuming 5%, 20% and 35% / h Starch k d for Low, Avg and Max scenarios, respectively.

33 Capturing Starch D Opportunities Rock River Laboratory, unpublished data

34 Formulating with CHO Digestion results Two core theories Empirical: NRC (2001) Biology or similar Old Book values Recent - 48 h in vitro digestion and other regression values Future Cow-level validated digestion coefficients TTNDFD (Combs, 2013) Rumen and T.T. starch digestion Mechanistic: CPM, CNCPS Biology or similar Old Book CHO k d and pool size values More recent Lab measured CHO k d and pool sizes Future More robust pool size, k d and k p measures NDF, Starch, protein fractions The next 15 years? Better agree with what cows say

35 Mechanistic model opportunities?

36 Empirical model opportunities?

37 Contact John Goeser, PhD PAS Office: on Twitter

38 References Combs, D.K TTNDFD: A new approach to evaluate forages. Proc Cornell Nutrition Conference for Feed Manufacturers. Syracuse, NY. Goering, H. K., and P. J. Van Soest Forage fiber analyses. Apparatus, Reagents, Procedures and Some Applications. In U. S. G. P. Office Agricultural Handbook No Agricultural Research Services, U.S. Dep. Agric. Washington, DC. Goeser, J.P Comparing new crop corn silage to old crop What might cause the new crop slump? Proc California Animal Nutr. Conf., Fresno, CA. Goeser, J.P What do the cows have to say about NDF and starch digestion? Proc Four State Dairy Nutrition and Management Conference. Dubuque, IA. pg Goeser, J.P, and C.R. Heuer Total tract NDF digestion predicted using rumen in vitro measures is related to commercial dairy in vivo total tract nutrient digestion. J. Dairy Sci. Vol. 97, E-Suppl. 1. Pg 775 Lopes, F. K. Ruh, D.K. Combs, L.F. Ferraretto, S.M. Fredin, C. Arndt, R.D. Shaver and L.E. Armentano Validation of a new approach to estimate total tract fiber digestibility from in vitro NDFD values. J. Dairy Sci. Vol. 97, E-Suppl. 1 pg National Research Council Nutrient Requirements of Dairy Cattle, 6th Revised Ed. National Academy Press, Washington, D.C. National Research Council Nutrient Requirements of Dairy Cattle. 7th Revised ed. National Academy Press, Washington, D.C. Tylutki, T.P., D.G. Fox, V.M. Durbal, L.O. Tedeschi, J.B. Russell, M.E. Van Amburgh, T.R. Overton, L.E. Chase and A.N. Pell Cornell net carbohydrate and protein system: A model for precision feeding of dairy cattle. Anim. Feed Sci. Tech. 143: Weiss, W.P Estimating the available energy content of feeds for dairy cattle. J Dairy Sci. 81:

39 Meta-analysis references Ferraretto, L.F. and R.D. Shaver Meta-analysis: effect of corn silage harvest practices on intake, digestion and milk production by dairy cows. Prof. Anim. Sci. 28: Ferraretto, L.F., P.M. Crump, and R.D. Shaver Effect of cereal grain type and corn grain harvesting and processing methods on intake, digestion, and milk production by dairy cows through a meta-analysis. J. Dairy Sci. 96: Firkins, J.L., M.L. Eastridge, N.R. St-Pierre, and S.M. Noftsger Effects of grain variability and processing on starch utilization by dairy cattle. J. Anim. Sci. 79(E. Suppl.):E Goeser, J.P Improvement of rumen in vitro NDF digestibility techniques and data analysis. PhD thesis. University of Wisconsin Madison, Madison, WI. Hannigan, M.D., J.A.D.R.N. Appuhamy, and P. Gregorini Revised digestion parameter estimates for the Molly cow model. J. Dairy Sci. 96: Krizsan, S. J., S. Ahvenjärvi, and P. Huhtanen A meta-analysis of passage rate estimated by rumen evacuation with cattle and evaluation of passage rate prediction models. J. Dairy Sci. 93: