Abstract #124
Section: Ruminant Nutrition (orals)
Session: Ruminant Nutrition 1: Protein and Amino Acid I
Format: Oral
Day/Time: Monday 12:00 PM–12:15 PM
Location: Junior Ballroom D
Session: Ruminant Nutrition 1: Protein and Amino Acid I
Format: Oral
Day/Time: Monday 12:00 PM–12:15 PM
Location: Junior Ballroom D
# 124
Histidine dose-response effects on lactational performance and plasma amino acid concentrations in lactating dairy cows.
S. E. Räisänen*1, C. F. A. Lage1,2, J. Oh1, A. Melgar1, K. Nedelkov1,3, X. Chen1,4, M. Miura5, C. Parys6, A. N. Hristov1, 1The Pennsylvania State University, University Park, PA, 2Universidade federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil, 3Trakia University, Stara Zagora, Bulgaria, 4University of Ulster, Belfast, UK, 5Ajinomoto Co, Inc, Kawasaki, Japan, 6Evonik Nutrition & Care GmbH, Hanau-Wolfgang, Germany.
Key Words: histidine, milk production, plasma amino acid
Histidine dose-response effects on lactational performance and plasma amino acid concentrations in lactating dairy cows.
S. E. Räisänen*1, C. F. A. Lage1,2, J. Oh1, A. Melgar1, K. Nedelkov1,3, X. Chen1,4, M. Miura5, C. Parys6, A. N. Hristov1, 1The Pennsylvania State University, University Park, PA, 2Universidade federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil, 3Trakia University, Stara Zagora, Bulgaria, 4University of Ulster, Belfast, UK, 5Ajinomoto Co, Inc, Kawasaki, Japan, 6Evonik Nutrition & Care GmbH, Hanau-Wolfgang, Germany.
The objective of this experiment was to determine the effect of increasing histidine (His) doses on milk production, milk composition and plasma amino acid (AA) concentrations in lactating dairy cows fed a diet that meets or exceeds their energy and metabolizable protein (MP) requirements. Sixteen Holstein cows [72 ± 15 d in milk, 46.7 ± 7.8 kg milk yield (MY)] were used in a replicated 4 × 4 Latin square design experiment with 4, 28-d periods. The targeted treatments were: (1) total mixed ration (TMR) with 1.8% digestible (d)His of MP, (2) TMR with 2.2% dHis (His2.2), (3) His2.2 supplemented with rumen-protected (RP)His to supply 2.6% dHis, and (4) His2.2 supplemented with RPHis to supply 3.0% dHis of MP. The actual dHis intakes were 1.83, 2.27, 2.95, and 3.2% dHis of MP, respectively. The diets supplied similar MP (2,695 ± 422 g/cow/d) and other nutrients, except dHis. Dry matter intake (DMI) and MY were recorded daily, and milk and blood sampling was performed on the last wk of each period. All data were analyzed using PROC MIXED of SAS with treatment, period and period × treatment in the model. Square and cow within square were random effects and DMI and MY were analyzed as repeated measures with ar(1) covariance structure. Linear and quadratic effects of His inclusion rate were tested. DMI was not affected by His dose (P = 0.52; averaging 23.4 kg/d; SEM = 1.42). There was a quadratic tendency for increased MY (P = 0.08; 41.5, 42.7, 43.3, and 42.3 kg/d, respectively). Lactose concentration (P < 0.01; quadratic effect) and yield (P < 0.001; linear effect) were increased by His. Milk true protein concentration was lower (P = 0.02) for His2.2 compared with all other treatments. True protein yield and milk fat concentration and yield were not affected (P ≥ 0.10) by treatment. Plasma concentration of His increased quadratically (P < 0.001) by His supplementation, as did Lys (P < 0.01) and the branched-chain AA (P < 0.02). In the conditions of this experiment, lactational performance of dairy cows fed a MP-adequate diet was optimized at dHis supply of 80 g/d, or 2.95% of MP.
Key Words: histidine, milk production, plasma amino acid
