Caponization is associated with some morbidity and mortality, which contributes to important economic losses. This practice is executed without any pain relief (neither anesthesia nor analgesia) and can be painful and without consideration of animal welfare. On the other hand, immunocastration accomplished by Improvac and Bovipriva in pigs and cattle represents a noninvasive procedure, and for that reason is regarded as an alternative with improved animal welfare. This study includes 4 experimental groups consisting of capons, slips, roosters, and birds submitted to the Improvac treatment. The administration of Improvac was associated with a considerable reduction in serum testosterone concentration (reduced by 79% compared to average serum testosterone of roosters). Regarding significant differences among experimental groups, birds from the Improvac group were intermediate between capons and slips with respect to abdominal fat pad weight and yield, breast meat water and protein contents, and femur length. Conversely, color parameters such as lightness, redness, and hue angle for Improvac birds were intermediate between roosters and capons. Thus, immunocastration with Improvac could represent an alternative solution to caponization, with considerable improvements in animal welfare.