ENERGY AND PROTEIN NUTRITION OF TRANSITION DAIRY COWS José Eduardo P ENERGY AND PROTEIN NUTRITION OF TRANSITION DAIRY COWS José Eduardo P. Santos Veterinary Medicine Teaching and Research Center School of Veterinary Medicine University of California - Davis

Grouping Dry Cows Dry period: Far off Close up Several metabolic and endocrine changes taking place associated with different nutrient requirements Parity Primiparous Multiparous Social interaction, competition, and different nutrient requirements

24 % 76 %

Four Major Tasks Must be Achieved During the Transition Period: Adapt the rumen to a high energy diet Rumen papillae and microflora Minimize the degree of negative EB Maintain normocalcemia Reduce the degree of immunosuppression around parturition

Dietary Energy Concentration, Papillae Surface Area and Rate of VFA Absorption (Dirksen et al., 1985)

Adapted from Hayirili, 1998

Energy for Prepartum Cows

Correlation between individual week prepartum DMI and postpartum DMI Putnam et al., (1997), Dann et al, 1999

Manipulation of Energy Content of the Diet Utilize better quality forages Ratio forage:concentrate Increase the level of NFC in the diet Supply a CHO source with greater rumen digestibility Add fat to the diet

Interaction Between Parity and Prepartum Dietary Fat on DMI (Hayirli et al., 1999)

Interaction Between Concentration of Dietary Fat and NDF on Prepartum DMI (Hayirli et al., 1999)

Prepartum DMI 13.6 vs 14.6 kg DMI; P<0.12 x = 1.88% SE = 0.06

Prepartum Treatment Effect on Milk Production +1.90 kg milk Pre P = 0.08

What about twin pregnancy and nutrient requirements?

Protein for Prepartum Cows NRC (1989) may underestimate protein requirements of close-up cows (Goff and Horst, 1998; Van Saun and Sniffen, 1996; Van Saun et al., 1993). Curtis et al. (1985) concluded that close-up cows receiving diets with more than 11% CP had less RFM and ketosis

Amino acid requirements for fetal growth and for synthesis of colostrum may deplete maternal protein reserves Amino acids can be used as gluconeogenic precursors Enhance complete oxidation of FA by the hepatic tissue Reduce TG infiltration into the liver Reduce ketogenesis

Nitrogen balance

Effect of Prepartum Dietary Protein Content on Lactation Performance of Dairy Cows (Santos et al., 2001) TRT x Parity: P < 0.05

Recommendations 2 groups of dry cows: far off and a close up Group primiparous separated from multiparous cows Social interaction Different nutrient requirements Feed a more nutrient dense diet during the close up period High quality forage (low K for close ups) High NFC diet Grain source of high rumen digestibility Fat ?

12% CP (35% RUP) prepartum seems adequate to multiparous cows Primiparous cows should be fed diets with 14 to 15% CP Consider using a high RUP source to increase CP and to raise RUP to 38 to 40% of the total CP Avoid extreme nutritional changes during transition Maximize DMI

Minerals and Vitamins Macro minerals*: Trace minerals*: Ca, P, Mg, K, S, Na, and Cl Trace minerals*: Fe, Zn, Cu, Mn, Se, Co, and I Fat Soluble Vitamins* A, D, and E Water Soluble Vitamins (?) Vitamins B (thiamin, biotin, niacin, etc) Vitamin C