Ractopamine hydrochloride in formulated rations for barrows or gilts from 94 to 130 kg

摘要

An experiment was carried out to evaluate the performance, carcass composition, cutting yields and economic viability of 5 or 10 ppm of ractopamine hydrochloride (RAC) in diets for barrows and gilts from 94 to 130 kg. Sixty commercial hybrid pigs within a gender, were individually kept in pens and assigned a randomized experimental block design, in a 3 × 2 factorial arrangement, with three levels of RAC (0; 5 and 10 ppm) and two sexs (barrows and gilts). There were no RAC × sex interactions for all evaluated parameters. There were significant improvements for the groups of RAC-treated on final weight, average daily gain (ADG) and feed:gain (F:G). The RAC, independent from the level (5 or 10 ppm), improved the F:G, but did not influence the average feed intake. The gilts had smaller final weight, smaller average feed intake and better F:G. The supplementation with 10 ppm of RAC provided better carcass yield, better longissimus muscle area and better meat percentage. The pigs supplemented with RAC showed better tenderloin yield, better ham weight and better meat percentage of ham. The gilts had better meat percentage, better back fat thickness, bigger belly flexibility and smaller fat thickness of the belly than barrows. On economic viability, the RAC-treated pigs increased the allowance index, gross earnings and net earnings. Compared to the barrows, gilts showed lower total cost, better allowance index and higher net earnings. The supplementation with 5 ppm of RAC was enough to improve performance, carcass composition and cutting yields in the heavy pigs. Furthermore, 5 or 10 ppm of RAC was economically viable and the heavy gilts were more profitable than heavy barrows.