Effects of milk production in liver lipid metabolism of dairy cattle during the transition period

ORTEGA, HUGO H; TRIONFINI, VALENTINA; SALVETTI, NATALIA; HEIN, GUSTAVO J; GAREIS, NATALIA C; REY, FLORENCIA; ANGELI, EMMANUEL

Buenos Aires

Congreso; LX Reunión Científica Anual de la Sociedad Argentina de Investigación Clínica.; 2017

The transition period (TP) is the most critical in the lactation of a dairy cow, characterized by a negative energy balance leading to an important lipid mobilization, where liver plays a key role in the metabolism. The aim of this study was to evaluate some pathways of hepatic lipid metabolism during the TP in the in cows with diferent milk production. Blood samples and liver biopsies from cows (n = 18) were taken at 28 and 14 days prepartum, and also at 4, 14, 28 and 60 days postpartum. Milk production were computed and cows were divided in high production (HP) a low production (LP) groups. Systemic non-esterified fatty acids (NEFA) and beta-hydroxybutyric (BHB), Aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), glucose, triglycerides, insulin concentrations and liver triglycerides were measured. Besides, the liver expressions of fatty acids oxidation enzymes, carnitine palmitoyltransferase-1 (CPT1), acyl-Coa oxidase-1 (ACOX1); and re-esterification enzyme, diacylglycerol acyltransferase-1 (DGAT1) and nuclear receptor PPAR-alpha were evaluated by Real Time-PCR and western blot. BHB, NEFA and LT concentrations were higher (p < 0.05) in HP, with the main different in days 4 and 14 postpartum. While glycemia and triglyceridemia were higher LP. The protein expressions PPAR-alpha were higher HP on days 60, while, genic expression of CPT1 were upper during all de postpartum period evaluated, with similar results of ACOX (p < 0.05). No differences in AST, GGT and mRNA expression of ACOX1 were observed (p > 0.05). These results show significant different in hepatic lipid metabolism of HC, maybe this group have major capacity of fatty acids oxidation. These knowledge could represent a useful tool to understand the metabolic behavior in animals with different milk production and to optimize the health of dairy cattle during this period.