Influência do estresse causado pela tosquia e aumento de peso ao nascer de cordeiros

Abstract

Reproductive losses in the southern region of Brazil have been a major problem for sheep farmers and studies in the area report that the weight of lambs at birth when greater than 4Kg allows it to survive during the winter period in which they are born. Due to the need for greater weight at birth, to ensure greater survival, numerous procedures have been performed in an attempt to promote lower mortality. The purpose of this work was to verify the influence of shearing on transplacental glycogen transport and its supposed relationship with the increase in birth weight in lambs (Ovies aries). For the realization of the project 9 sheep of the Australian Merino breed were used which were raised at the Federal University of Rio Grande do Sul - Porto Alegre / RS) - UFRGS in collaboration with the Lutheran Brazilian University - ULBRA. The animals were divided into 2 groups: the first with 5 sheared animals (OVE) at 70 days of the perinatal period and the second with four animals that were kept as control (OVC). The fetuses were collected through a surgical cesarean section performed at the end of pregnancy. For comparative purposes, placental and fetal weight were initially measured; to characterize the placenta, the number of placentons and the length, width and thickness of the placentonium were quantified, with the aid of a caliper. The collected placental material was fixed, dehydrated, diaphanized and included in paraffin, for later making slides and quantifying glycogen. As a partial macroscopic result, the placentas of the sheep in the sheared group had a weight 13% greater than those in the control group, in the fetuses the difference was more expressive, the weight of the fetuses sampled in the sheared group was 25% greater than those in the second group. The differences between the measures of thickness, length and width were insignificant, but always with higher rates in the tested group.