The objective of this study was to comparatively evaluate the effect of a glucogenic and lipogenic diets on milk production, milk composition and blood serum metabolites in high-producing dairy cows in early lactation. Cows (n = 12) were randomly assigned to 1 of 2 diets and were fed either a mainly lipogenic diet or a mainly glucogenic diet, from 3 week before the expected calving date until 4 week postpartum. Cows were fed a total mixed ration (TMR) twice a day at 0800 and 1800 h and had free access to water. Cows were individually housed in tie stalls during the entire dry period and lactation. There was no effect of diets on body weight and body condition score before and after calving. Dry matter intake (prepartum and postpartum), milk yield, milk fat, milk protein, milk lactose and milk solid non-fat percentage did not differ significantly between the diets, however the effect of time (week) was significant (P<0.01). In prepartum and postpartum, no difference was found in serum non-esterified fatty acids (NEFA), β-hydroxybutyrate acid (BHBA), aspartate aminotransferase (AST), glucose and blood urea nitrogen (BUN), but was found a significant difference in blood serum cholesterol in pre and postpartum (P<0.01). It was concluded that the glucogenic diet and the lipogenic diet did not influence significantly production efficiency and metabolic parameters of cows in transition period.

Keywords