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Responses to methionine, lysine plus histidine and energy supply on mammary metabolism in dairy cows
- Source :
- Book of abstracts, 71. Annual Meeting of the European Federation of Animal Science (EAAP), 71. Annual Meeting of the European Federation of Animal Science (EAAP), EAAP, Dec 2020, Virtual meeting, Portugal
- Publication Year :
- 2020
- Publisher :
- HAL CCSD, 2020.
-
Abstract
- International audience; Our objective was to study how balancing Lys, Met and His (LMH) at 2 supplies of net energy of lactation (NEL) affect milk yield and composition. Four Holstein cows received duodenal infusion of 2 amino acids (AA) mixtures and 2 dietary levels of NEL (E-: 31.5 vs E+: 35.9 Mcal/d), combined in factorial arrangement, distributed in a 4×4 Latin square, with 3-wk periods. The 2 AA mixtures, both providing 92±2 g/d of PDI (metabolisable protein in INRA, 2018), contained (g/d) Lys (28), Met (9), His (9) and non-essential AA (NEAA) in LMH+ or only NEAA in LMH-. Diets plus infusions provided 5.8, 2.0 and 2.0% of PDI of Lys, Met and His respectively in LMH- compared to 7.1, 2.4 and 2.4% PDI in LMH+; LMH+ met INRA (2018) requirements of 7.0, 2.4 and 2.4% PDI for these 3 AA, respectively. The mammary uptake (MU) of metabolites were measured on day 20 (6 samples at 2-h intervals) of each period, mammary plasma flow being estimated using the Fick principle (Phe+Tyr). Analyses of variance of these data included the effects of LMH, NEL and interaction using a MIXED procedure (SAS) with cow as random effect. No interaction was observed on milk composition (P>0.22). Balancing LMH tended to increase (P=0.07) and increasing NEL supply increased (P≤0.02) milk and fat yields averaging respectively 28.2, 29.6, 30.1 and 31.2±1.33 kg/d and 1,289, 1,317, 1,363 and 1,410±55.1 g/d for E-LMH-, E-LMH+, E+LMH- and E+LMH+. Both treatments increased (P
Details
- Language :
- English
- Database :
- OpenAIRE
- Journal :
- Book of abstracts, 71. Annual Meeting of the European Federation of Animal Science (EAAP), 71. Annual Meeting of the European Federation of Animal Science (EAAP), EAAP, Dec 2020, Virtual meeting, Portugal
- Accession number :
- edsair.dedup.wf.001..bf196cae41ccb60476812c6e5f2e1021