Período de suplementação de ractopamina em dietas para fêmeas suínas pesadas: características de carcaça e viabilidade econômica

Abstract

This study aimed to evaluate the effects of ractopamine supplementation in diets administered at two different periods on the carcass characteristics of finishing pigs, as well as the economic feasibility of its use. Twenty-four gilts at 100 days of age were used, distributed in a randomized block experimental design with 3 treatments and 8 repetitions, with the experimental unit being a pen with one animal. The treatments consisted of: T1 - Control diet without ractopamine supplementation; T2 - Diet containing 10ppm of ractopamine administered from day 142 to 170; T3 - Diet containing 10ppm of ractopamine administered in two periods, from day 128 to 142 and from day 156 to 170. There was no effect of ractopamine supplementation in the diet of gilts on feed intake, slaughter weight, animal price, average cost per kg of live weight, economic efficiency index, cost index, and net income without bonus. However, it was observed that dietary supplementation of ractopamine, regardless of the administration period, resulted in higher hot carcass weight, loin depth, bonus index, and net income with bonus. Gilts supplemented with ractopamine in two periods had lower fat depth and a higher amount of lean meat compared to non-supplemented females, not differing from those receiving 10ppm of ractopamine only from day 142 to 170. In conclusion, dietary supplementation of 10ppm ractopamine during the finishing phase for female pigs, regardless of the supply period, improves carcass characteristics. However, when provided in 2 periods (day 128 to 142 and day 156 to 170), it reduces fat depth and increases the amount of lean meat. In the evaluated economic scenario, ractopamine supplementation increases the net income with bonus for gilts carcasses.