Effects of energy and protein status on reproductive parameters and presence of subclinical ketosis in Brown Swiss cows postpartum

This study aimed to determine protein and energy metabolites in postpartum Brown Swiss cows and their effect on the presence of subclinical ketosis and reproductive parameters. One hundred cows from four farms in the Mantaro Valley (Junín, Perú) were grouped according to parity (1, 2, 3 and 4). The variables of the metabolic profile (total proteins, blood urea nitrogen [BUN], glucose, βhydroxybutyrate [B-HB]), milk production and body condition were estimated between 7 to 60 days postpartum in 7-day intervals. Likewise, the calving-first heat interval and the pregnancy rate at first service were recorded. The determination of subclinical ketosis was based on a semi-quantitative analysis by levels of B-HB in milk (µmol/l) using a commercial kit. BUN levels ranged between 11.74 and 15.92 mg/dl, being higher in fourth parity cows (p<0.05). The averages of total protein (6.54-7.90 g/dl) were homogeneous between calvings. The glucose values presented an inverse response, being lower in cows of third and fourth parity compared to cows of first and second parity (p<0.05). Similarly, the highest levels of milk production were observed in third parity cows (14.41 ± 5.42 l/d) and fourth parity (15.43 ± 4.36 l/d) with respect to first and second calvers (p<0.05). Body condition was lower in cows with subclinical ketosis. The calving - first heat interval and the pregnancy rate at first service were lower in cows with subclinical ketosis (p<0.05).