Efecto del balance energético negativo sobre el desarrollo ovárico en vacas lecheras posparto.

Abstract

The objective of the present study was to evaluate the effect of the negative energy balance, on ovarian development; as well as the presentation of the first heat, in dairy cows in the postpartum period. The negative energy balance in dairy cows in the postpartum period can generate metabolic disorders, associated with diseases that affect the reproductive and productive condition of bovine females. For this, three groups were carried out, concerning the postpartum period of the experimental units; group one, early postnatal period; group two, middle postpartum period and group three of the late postpartum period; from which a blood sample was taken to determine plasma insulin levels, as well as the determination of the development of ovarian structures, through serial ultrasound checks, and the observation of the presentation time of the first heat after delivery. Dairy cows when they have plasma insulin levels in ranges below 3.3 Ul/ml are affected by the state of negative energy balance, which significantly influences the development of follicles and corpus luteum. The presence of Negative Energy Balance (NEB) found in dairy cows has a negative influence on the development of ovarian structures and the period for the presentation of the first postpartum heat, increasing the percentage of days in the herd. It is recommended to research the influence of the NEB on the parameters related to the dietary cation- anion equilibrium and its impact on reproductive performance, immunological quality of colostrum.