Anestrus recovering time in cross bred milk cows thin

Abstract

The aim of this experiment was to determine the time required for the reestablishment of the ovarian luteal cyclic activity (OLCA) in dry crossbred Holstein-Zebu (HZ) cows, thin and in anestrus with inactive ovaries. Twelve animals with an average weight of 315.0  29.4 kg, were fed with forage and concentrate, in order to gain weight until reestablishment of OLCA. Blood samples for Progesterone analysis and weight measures of the animals were taken weekly. Estrous cycles onset was determined by plasma P4 level > 1.0 ng/ml, by ovarian rectal palpation and visual estrus detection. The OLCA recovery time was 114.0  37.9 days, after an overall weight gain of 77.7  11.2 kg/animal, which is equivalent a 0.68 kg/day gain. The six control animals received a maintenance diet for the low weight and remained in anestrus during the experiment. The delay in the OLCA recovery time in crossbred HZ cows, thin and in anestrus shows how is undesirable to allow the animal to get in anestrus by sub nutrition. There is increase on the service time as well as on the parturition interval, with a negative impact on the economic performance of the dairy activity.