Parâmetros metabólicos e produtivos de vacas leiteiras no período de transição

Abstract

The transition period has been described as a critical and determinant for the productivity and health of modern dairy cows. The objective of this study was to monitor the health and metabolism of dairy cows through the use of metabolic and productive parameters during the transition period. The study had been conducted at the Experimental Gloria’s Farm of Federal University of Uberlandia, in Uberlândia - MG. Metabolic and productive parameters were monitored from 102 crossbred dairy cows (47 primiparous and 55 multiparous) during 2016 February to 2017 May. These cows were evaluated on days -28, -21, -14, -7, day of delivery, 6, 12 and 24 hours, 2, 5, 7, 14, 21 and 28 days in relation to delivery. A completely randomized design was used, in a 4x14 factorial scheme (season and diet) and 2x14 (prepartum mineral nucleus, calving order, mastitis occurrence in the first 30 days in milk, and occurrence of ketosis and hypocalcemia in the pre and postpartum period). It was evaluated parameters such as body condition score, live weight, urinary pH, serum levels of β-hydroxybutyrate and calcium, and milk fat:protein ratio. The lowest mean serum calcium value obtained in the present study was 7.2 ± 1.7 mg/dL at 12 hours postpartum, with a mean subclinical hypocalcemia incidence of 56%. The mean values of β-hydroxybutyrate found were 0.72 mmol/L for the prepartum period and 1.03 mmol/L for the postpartum period, and the highest value obtained during the evaluation period was 1.23 ± 0.52 mmol/L on the 5th postpartum day. The mean percentage value for ketosis incidence was 47%. The use of metabolic and productive parameters to monitor dairy cows allowed to conclude that these animals are susceptible to the occurrence of metabolic disorders in the transition period.