Early lactation dairy cows undergo metabolic adaptations at the time of parturition and onset of lactation, increasing their risk of hepatic lipidosis. Effects of branched chain amino acids and branched chain keto-acids in early lactation were determined in 2 experiments. In experiment 1, primary bovine liver cells enriched with hepatocytes (PLEH) were exposed to media mimicking the circulating environment of early lactation cows without (FA) and with (BCKA) branched chin keto acid for 72h. The BCKA effectively decreased intracellular triglyceride accumulation in PLEH compared to FA. Expression of genes controlling lipid metabolism, such as decreased lipid uptake, increased Îø oxidation, increased antioxidant response, decreased apoptosis, and a recorded decrease in mitochondrial membrane potential was identified in the BCKA treatment. In the 2nd experiment, 36 multiparous dairy cows were enrolled on a randomized block design and were treated from 1 -21 days postpartum, with 1 of 3 abomasally infused treatments; 1) saline (CON); 2) BCAA, including 67 g valine, 50 g leucine, and 34 g isoleucine; and 3) BCKA, including 77 g ketovaline, 57 g ketoleucine, and 39 g ketoisoleucine. No alterations to body weight, body condition and dry matter intake were recorded between treatments. The BCAA infused cows produced increased milk, fat, and lactose yield relative to the CON. Abomasal infusion of BCKA decreased liver triglyceride compared to CON. In conclusion, branched chain keto-acids alter hepatic lipid metabolism and decreased hepatic triglyceride accumulation while branched chain amino acids alter milk production.
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