Desempenho reprodutivo de novilhas de corte expostas a diferentes métodos de bioestimulação

Abstract

EnglishThe objective of this study was to evaluate the reproductive performance of beef heifers exposed or not to different sexual biostimulation treatments. Two hundred and twenty Aberdeen Angus heifers, 24 months old were used. Heifers were divided into three groups: group one, using teaser bull consisted of 73 heifers exposed, for 60 days previous to AI, to vasectomized males. The second group consisted of 73 heifers exposed during the same period to androgenized cows. The third group consisting of 74 heifers was the control group. After the treatments (60 days) started the breeding season. Variables analyzed were the weight at the beginning and the end of treatment, ADG, the pregnancy rate, and the interval between the start of breeding season and conception. Fixed factors considered were the three treatments. Heifers biostimulatated with androge- nized cows had a earlier conception, (p Biostimulation can not change rates of pregnancy in beef heifers. The use of biostimulation with cows androgenized anticipates the conception in beef heifers of two years old. portuguesO objetivo deste estudo foi avaliar o desempenho reprodutivo de novilhas de corte submetidas a diferentes metodos de bioestimu- lacao. Foram utilizadas 220 novilhas Aberdeen Angus de dois anos de idade. Setenta e tres novilhas foram mantidas com machos caudecto- mizados, 73 com vacas androgenizadas e 74 nao receberam tratamento bioestimulatorio. Os tratamentos tiveram duracao de 60 dias pre- acasalamento. Os fatores fixos analisados foram os tres tratamentos. As variaveis resposta foram os pesos ao inicio e fim dos tratamentos, ganho medio diario (GMD), o indice de prenhez e dias para a concepcao (medido atraves da data de parto ajustada a data de inseminacao). Nao houve diferenca (p>0,05) nos indices de prenhez obtidos entre os tratamentos. A concepcao foi antecipada (p