Productive performance and economic viability of beef cattle subjected to different castration methods in the Western Amazon

Abstract

This study aimed to assess the productive performance and economic viability of intact, surgically castrated, and immunocastrated cattle. The experiment was completely randomized with 102 animals divided into three treatments: intact (control group), surgically castrated (group I), and immunocastrated (group II). Animal production indices, circulating testosterone levels, carcass yield and finishing, and profit generated by each method after slaughter were determined. Control group and immunocastrated animals showed a higher (p<0.05) total weight gain (TWG) than surgically castrated animals, with means of 181.85, 170.34, and 148.88 kg, respectively. Average daily weight gain (ADG) in immunocastrated was higher (p<0.05) than that obtained by surgically castrated, not differing (p<0.05) from intact animals, with means of 0.534, 0.466, and 0.570 kg/animal, respectively. The assessment of the degree of finishing showed that surgically castrated animals had an adequate fat deposition (three to six millimeters) and maturity. On the other hand, immunocastrated animals presented 50.0% of carcasses with tolerable classification, 36.11% desirable, and 13.89% undesirable. Control animals had a higher testosterone concentration than the other groups (p<0.05), with a mean of 128.56 ng/dL. Immunocastrated animals had a 60.91% reduction in testosterone concentration compared to control animals. However, these were significantly higher (p<0.05) than surgically castrated animals, which had a mean concentration of 12.34 ng/dL, representing a reduction of 90.4% in comparison with control animals. Therefore, immunocastration reduced the damages caused by surgical castration and qualitatively improved the carcass of Nellore animals, thus joining animal welfare and production. However, intact animals showed higher profitability.