Blood testosterone level and growth of castrated, uncastrated, and cryptorchid lambs

Abstract

The objective of this study was to evaluate the effects of sexual status on blood testosterone levels and its influence on lamb growth. A total of 49 Texel x Corriedale males, originating of single births, were divided into three groups: uncastrated (n = 16), castrated (n = 17) and cryptorchid (n = 16), in the State of Rio Grande do Sul, in extensive natural pasture, with feed supplementation after weaning. The effect of the sexual status was examined by analysis of variance. Uncastrated and castrated lambs showed higher body weight, thoracic perimeter, and body compactness between the 35th and 203th day of age. Uncastrated lambs had mean weight higher than cryptorchid lambs over the whole period. Cryptorchid lambs had an average weight gain greater than castrated lambs between the 203rd and 259th days. Castrated lambs had a higher body condition score on the 147th day than the cryptorchid lambs, and on the 175th and 203rd days than uncastrated and cryptorchid lambs. Blood testosterone concentrations were higher in the uncastrated and cryptorchid lambs on the 203rd and 231st days and in the overall mean. The findings of this study showed that, with advancing age, the sexual status affects the testosterone production, not showing differences regarding growth at young ages.

Keywords

• Castração
• Criptorquidismo
• Hormônio masculino
• Ovis aries.