Comportamento de fêmeas suínas imunocastradas

Abstract

The market weight is crucial to the pork supply chain efficiency. As the animals’ growth pattern is altered with sexual maturity, the estrus in the female is one of the factors that must be considered in the establishment of the harvest weight. This study aimed to compare the behaviour of entire gilts with gilts immunocastrated at different ages. Seventy-two animals from industrial crossing (Agroceres x Topigs), 105 days old were used. The female pigs were distributed in 3 treatments according to a randomized design. The immunocastration vaccine was applied in two groups, six weeks before slaughter (I6) and four weeks before slaughter (I4). The non-immunized group (NI) was used for comparison. Social behaviour was analysed through the collection of images by a monitoring camera positioned in each of the six pens. The analysis period was from 6 am to 6 pm, with data taken at every ten minutes. Eating behaviour data was collected by the automated FIRE® system. Due to the divergence in the time of immunization in the two groups, an individual comparison of each immunocastrated group with the control group (NI vs. I6 and NI vs. I4) was performed. Anti-GnRH immunization did not influence most of the variables analysed. However, there was a variation in the eating behaviour of group I6, with a reduction in the number of visits to the feeder and an increase in food consumption per visit. These findings suggest the immunocastration vaccine suppresses the effects of the estrus period, while it does not directly affect social aspects of behaviour.