Fatores que afetam perda embrionária tardia em vacas leiteiras mestiças

Abstract

In order to extract the maximum productive potential from the dairy activity, it is necessary to have good control of the reproductive efficiency of the herd. However, there are many obstacles to achieving good reproductive rates, and one of the factors that most influence the low reproductive efficiency of properties and, consequently, generate economic losses are pregnancy losses, which can be classified as early embryonic losses, which occur until the twenty-fifth day of pregnancy; late embryonic losses, which occur from the twenty-fifth to the forty-fifth day; and the fetal losses that occur subsequently until the moment of calving. The objective of the study was evaluate the embryonic losses of 2021 and 2022 in the dairy herd from the Experimental Farm of Glória, from the Federal University of Uberlândia, located in Uberlândia- MG. For the execution of the project, data were compiled from field worksheets on the reproductive management of the herd, composed by crossbred cows, underwent a fixed-time artificial insemination (FTAI) protocol. Pregnancy diagnosis was performed by ultrasound examination 31 days after TAI and confirmed at 52 days. Embryonic loss was considered when the cow was pregnant in the first exam and non-pregnant in the confirmation exam. A descriptive analysis of the embryonic loss data in relation to animal category and season of the year was carried out. During the period of analysis, a low occurrence of embryonic losses was detected on the farm, where it was 5.6% in heifers and 5.7% in cows. As for the season, during spring/summer, a rate of 4.6% was recorded and autumn/winter 8.6%. Based on the results, it is suggested that the low incidence of embryonic losses on the farm was due to the fact that the animals do not have a high milk production, in addition to the accuracy of the pregnancy diagnoses and low health challenge in the herd.