How to Meet the MP & AA Needs of Most Cows

Transcription

1 How to Meet the MP & AA Needs of Most Cows 2012 RP Feed Components, LLC MP, Met, & Lys Needs of Prefresh Cows What do the Models and Experts Say? MP, g/d Met, g/d Lys, g/d Nutrition Models (4) 820 1, Expert 1 1,100 1, Model/Expert Avg 1, % MP 6.9% MP 1,600 lb Mature Holstein 275 Days Preg 25 lbs DMI 95 lb Calf 1

2 Why be Concerned about MP and AA Prefresh? During the first 7 10 d of lactation dairy cows may need to mobilize as much as 1000 g tissue protein/d to satisfy the mammary gland s demand for amino acids and glucose. (Bell et al., 2000) Depletion/Mobilization of labile protein reserves prior to calving reduces the amount available after parturition. Results are Mixed when Increasing CP Prefresh 6/15 2/15 7/15 Bell et al. (2000) 2

3 Why are Results Mixed when Increasing CP Prefresh? In pregnant dry cows the relationship between CP intake and MP and AA supply is variable and dependent on: 1.Feed Intake 2.AA Composition and Level of Dietary Protein 3.Fermentable OM for Rumen Microbial Protein Synthesis Bell et al. (2000) Number or Percentage Prepartum DMI Varies (A Lot) in Prefresh Pens 1. 50% Eat Less Than Avg 2. 16% Eat 80% of Avg % of Cows % of Cows Avg = 27 lbs SD = 5.5 lbs % of Cows Phillips et al. (2003) 3

4 Number or Percentage Prepartum DMI Varies (A Lot) in Prefresh Pens % % Avg = 27 lbs SD = 5.5 lbs % Phillips et al. (2003) 21 d Postpartum DMI, lbs Relationship Between Pre and Postpartum Intake Postpartum DMI (lbs) = 1.13 x Prepartum DMI R² = 0.59 Pre DMI = 23 lbs Post DMI = 26 lbs SD = 4.4 lbs Pre DMI = 30 lbs Post DMI = 35 lbs SD = 5.5 lbs High R 2 2. Slope 20 Holstein 3. Variation At risk Cows Jersey d Prepartum DMI, lbs French (unpublished) 4

5 Prefresh DMI Variability Has To Be Considered! What does all this Mean? 15% of Cows consume at least 5 lbs less DM than Pen Avg or ~25 lbs DM This same 15% consume ~20 lbs DM the week before calving If you re balancing the ration for 30 lbs DMI and 15% of the cows are consuming less than 20 lbs DM, then it is reasonable to assume that these cows are in negative nutrient balance How to Account for Variability in Prefresh Cows Not all cows consume the average (½ more and ½ less) We can account for most of those eating less than average Std Dev of transition intake is 4.8 lbs, as a ref SD in a one group herd is 6.8 lb 5

6 Development of Adjustment Factors to Meet the MP & AA Needs of Prefresh Cows MP, g/d Met, g/d Lys, g/d Benchmark 1, To meet the requirement of 50% of the cows 1,080 g MP/d, 25 g Met/d and 75 g Lys/d To meet the requirement of 83% of the cows, multiply by g MP/d, 30 g Met/d and 90 g Lys/d To meet the requirement of 95% of the cows, multiply by g MP/d, 32 g Met/d and 97 g Lys/d Prefresh MP Database Study Trt N Caldari Torres et al., 2011 (FL) 2 20 DeFrain et al (SD) 4 40 Doepel., et al 2002 (CAN) 4 28 Janovick and Drackley, 2010 (IL) 3 24 Ji et al., 2012 (IL) 2 14 Morey et al., 2011 (KA) 1 7 Peterson et al., 2005 (MI) 3 42 Sadri et al., 2009 (IRA) 4 32 Smith et al (NY) 2 72 Stone et al., 2012 (NY) 2 70 Winkelman et al., 2008 (OH) 2 18 Yuan et al., 2012 (WI) 1 15 Total

7 Database Requirements Multiparous Holstein Cows d Prefresh to d Postfresh DMI Milk Fat & Protein Rations and Cows Adequately Described to Model in CNCPS Prefresh Ration Summary Item Mean Min Max DMI, lbs (SD) 28.5 (4.7) ME, Mcal/d ME Bal, Mcal MP, g/d 1, ,687 MP Bal, g gmp/kg DM CP, % NDF, % Starch, % Met, g/d Lys, g/d

8 Postfresh Ration Summary Item Mean Min Max DMI ME, Mcal/d ME Bal, Mcal MP, g/d 1,890 1,355 2,356 MP Bal, g gmp/kg DM CP, % NDF, % Starch, % Met, g/d Lys, g/d BW, BCS, & Production Item Mean Min Max Pre BW, lbs 1,634 1,490 1,787 Pre BCS Post BW, lbs 1,447 1,322 1,541 Post BCS Milk, lbs/d Fat, % Fat, lbs/d Protein, % Protein, lbs/d FCM:DMI

9 Prefresh PostfreshDMI Plot Postfresh DMI, lbs/d y = 0.72x + 17 R² = Prefresh DMI, lbs/d Effect of Prefresh MP on Protein Yield y = x R² = 0.12 Milk Protein, kg/d What about Experiments where Postfresh MP severely deficient? Prefresh MP, g/d 9

10 Effect of Prefresh MP on Protein Yield y = x R² = ,369 g MP Milk Protein, kg/d Removed Experiments where Postfresh MP <75% of Requirement 0.80 Every 1 g MP Prefresh = 0.6 g Milk Protein Postfresh Prefresh MP, g/d Amino Acid Mobilization Begins Prefresh Muscle mobilized prior to fat Cows with higher 3 MH concentrations had lower BHBA conc Higher mobilization of protein around calving may restrict ketones van der Drift et al. (2012) 10

11 Effect of Prefresh Met on Protein Yield y = x R² = g Met Milk Protein, kg/d Prefresh MP Met, g/d Effect of Prefresh Lys on Protein Yield y = x R² = g Lys Milk Protein, kg/d Prefresh MP Lys, g/d 11

12 Xu et al. (1998) 1. NC (86% of MP Lys and 90% of MP Met Req) 2. PC (112% of MP Lys and 103% of MP Met Req by supplementing blood, fish and meat & bone meal) 3. NC + RPAA (Post 27 g/d of MP Lys and 8 g/d of MP Met; Pre 13.5 g/d of MP Lys and 4 g/d of MP Met) 4. NC + Hi RPAA (Post 40 g/d of MP Lys and 13 g/d of MP Met; Pre 13.5 g/d of MP Lys and 4 g/d of MP Met) Prefresh Ration NC PC NC+RPAA NC+Hi RPAA DMI 20.5 a 24.5 b 20.7 a 23.8 b CP, % NDF, % Starch, % ME, Mcal MP Met Lys

13 Postfresh Ration NC PC NC+RPAA NC+Hi RPAA DMI 35.6 a 37.7 a 38.3 a 46.3 b CP, % NDF, % Starch, % MP Met Lys Milk, lbs/d 74.5 a 86.8 b 82.7 b 86.0 b Milk Fat, lbs/d 2.67 a 2.98 b 3.15 bc 3.31 c Milk Prot, lbs/d 2.27 a 2.62 bc 2.51 c 2.80 b Three Strategies 6 phases 13

14 Conclusions Published Study Database As prefresh MP, Met, and Lys intake increase, so does milk protein yield; with maximal yield at ~1,300 g MP, 30 g Met, and 90 g Lys Postfresh MP supply must be reasonable (>75% requirement) Xu et al. (1998) Study Confirm that prefresh and postfresh AA supply is coupled and need to focus on both! RPFC s Goals for a Close up Diet DMI, lbs/d NE L, Mcal/lb MP, g/d 1300 Met, g/d 30 Lys, g/d 90 Starch, % NDF, %

15 Thank You for Attending the Penn State Dairy Nutrition Workshop Post Conference Seminar!