Milk yield and mammary metabolism in response to increasing amino acids and protein supplies - INRAE - Institut national de recherche pour l’agriculture, l’alimentation et l’environnement
Conference Poster Year : 2023

Milk yield and mammary metabolism in response to increasing amino acids and protein supplies

Abstract

The aim of this study was to understand milk yield variations in response to a balanced profile of 10 essential amino acids (EAA) at 2 levels of metabolizable protein (MP) supplies. Diets and infusions provided 14.5 vs 16.8 g/MJ for MP∙NEL-1 in INRA 2007 system and 128 vs 145 g/kg DM of CP, respectively in Low vs high MP. Four lactating dairy cows received 2 dietary treatments (low vs high MP) and 2 different duodenal infusions of 10 EAA (AA- and AA+), according to a 2×2 factorial design. The AA- and AA+ treatments provided (in % of MP) 1.7 vs 2.4% of Met, 5.8 vs 7.0% of Lys, 7.9 vs 9.0% of Leu and 1.9 vs 3.0% of His, respectively. Six blood samples were collected from carotid artery and mammary vein to calculate the uptakes of all the energetic nutrients using the Fick principle on Phe + Tyr for mammary plasma flow. Results were analysed using the MIXED procedure of SAS (2009) taking the effect of cows as random. Milk yield increased in AA+ vs AA- treatments (9.1 vs 8.6 kg/12 h∙per half udder, P=0.04), with no significant difference in lactose yield between the 2 treatments (442 vs 422 g/12 h∙per half udder). However, the water content in milk was higher in the AA+ vs AA- treatments (7.90 vs 7.45 kg/12 h∙per half udder, P=0.05) and explained by a parallel increase in minerals yield (69 vs 64 g/12 h∙per half udder, P=0.05). Mammary net uptake of glucose (GLC) tended to increase in AA+ vs AA- treatments (1,729 vs 1,562 mmol/h of C, P=0.06) as the difference between GLC minus lactose (504 vs. 391 mmol/h of C, P<0.1). This indicates that there was a shift in GLC partition towards ATP furnishing to support the increased milk protein yield (MPY; from 262 to 290 g/12 h∙per half udder; P=0.01). In conclusion, milk volume could vary differently than lactose yield and MPY contrary to the meta-analysis of Daniel and Sauvant and the predictions of INRA (2018) model as it depends on minerals in response to EAA supplies.
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Dates and versions

hal-04284061 , version 1 (14-11-2023)

Identifiers

  • HAL Id : hal-04284061 , version 1

Cite

Sophie Lemosquet, Christelle Loncke, Jean-Charles Anger, Auxane Hamon, Jocelyne Guinard-Flament, et al.. Milk yield and mammary metabolism in response to increasing amino acids and protein supplies. 74. Annual meeting of the european federation of animal science (EAAP), Aug 2023, Lyon, France. Wageningen Academic Publishers, Book of abstracts, 29, pp.334, 2023, Book of abstracts of the 74th annual meeting of the european federation of animal science. ⟨hal-04284061⟩
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