Efeitos da nutrição no desenvolvimento ovariano fetal durante o início da gestação em vacas Nelore

Abstract

Environmental influences such as nutritional restriction during early gestation may impair fetal development and compromise functions in adulthood. Ovarian development occurs during early gestation. We hypothesized that restriction or excess of nutrients ingested by cows during the first 60 days of pregnancy affects fetal body weight and ovarian development. Fifty uniparous Nelore cows were subjected to Timed Artificial Insemination with sexed semen (female) of a single bull and individually allocated on different diets. The diet used for the control group met the maintenance requirements and the groups with high and low either 180% or 60% of maintenance, respectively. Venous blood samples were collected for plasma progesterone, LH, insulin and leptin quantification. At 60 days of gestation, eight fetuses were removed by colpotomy (accessed through the vagina), weighed, ovaries were dissected and weighed. One fetal ovary (of each pair) was used for transcriptional analysis by RNA-seq. It was observed that maternal nutritional status during the first 60 days of gestation: 1) progesterone, insulin and leptin levels which were lower in the group with low; 2) the relative ovarian weight / body weight of fetuses in the high intake group was higher compared to the others groups; 3) ovarian gene expression patterns differedbetween control, high and low groups. Thus, we conclude that changing maternal nutrition during the first 60 days of gestation affects the development and transcriptomic profile of fetal ovaries