INFLUENCE OF PREPARTUM PROTEIN AND ENERGY CONCENTRATIONS FOR DAIRY GOATS DURING PREGNANCY AND EARLY LACTATION

Sixty-three multiparous Alpine does were blocked by pregnancy type (si ngle vs. multiple) on d 90 of pregnancy and assigned to one of nine di ets to evaluate the interaction of prepartum protein and energy intake on BW change, kidding, and subsequent production and composition of m ilk. Treatments were factorial with three percentages of CP (8.5, 11.5 , and 14.5% of DM) and three concentrations of metabolizable energy (1 .80, 2.16, and 2.53 Mcal/kg of DM). Does were fed for ad libitum intak e during pregnancy and switched to a lactation diet (16% CP and 2.35 M eal of metabolizable energy/kg of DM) after parturition. Milk producti on and composition were recorded for the first 15 wk of lactation. Pre partum BW gain increased quadratically as protein amount increased but was unaffected by energy. Kidding rate, litter weight, and gestation length were unaffected by protein or energy amounts. Milk production i n the subsequent lactation increased quadratically in response to prep artum CP (2.59, 3.26, and 3.07 kg/d for 8.5, 11.5, and 14.5% CP, respe ctively). Milk production increased linearly in response to prepartum metabolizable energy concentration (2.63, 3.05, and 3.26 kg/d for 1.80 , 2.16, and 2.53 Mcal/kg of DM, respectively). Milk fat percentage inc reased linearly in response to increased prepartum energy. Production of milk fat, protein, SNF, FCM, and SCM were affected quadratically by increased prepartum CP and linearly by prepartum energy, following th e pattern for milk production. The present recommendations for prepart um CP and energy appear to be adequate for gestation and subsequent la ctation performance of dairy goats.