Desempenho, características de carcaça e composição óssea de suínos alimentados com diferentes níveis de ractopamina e fitase

Abstract

RESUMO -O experimento foi conduzido com objetivo de avaliar o efeito da utilização de ractopamina e fitase em dietas para suínos no período final de terminação sobre o desempenho, as características de carcaça e a composição mineral no osso terceiro metacarpo. Foram utilizados 240 suínos machos castrados com peso inicial de 100,7 ± 3,9 kg, em delineamento de blocos ao acaso, em arranjo fatorial 2 × 3, com dois níveis de ractopamina (5 ppm e 10 ppm) e três de fitase (0, 500 e 750 uf), totalizando seis dietas, avaliadas em cinco repetições de oito animais por unidade experimental. O experimento teve duração de três semanas e, ao final, os animais foram abatidos para avaliação de carcaça. Não houve interação entre os níveis de ractopamina e fitase para nenhuma das variáveis. O peso corporal, o consumo diário de ração, a perda de peso durante o transporte, o percentual de carne magra e os teores de cinzas, fósforo e flúor no osso não foram influenciados pelas dietas. O nível de 10 ppm de ractopamina foi o que promoveu melhores resultados de ganho de peso, conversão alimentar, peso de carcaça quente, carne magra total, índice de bonificação e teor de cálcio no osso. Os níveis de fitase avaliados não influenciaram o desempenho nem as características de carcaça, exceto o rendimento, que foi maior nos animais alimentados com a dieta contendo 500 uf em comparação àqueles que não receberam fitase. Dietas com 10 ppm de ractopamina proporcionam melhor desempenho e características de carcaça em comparação a dietas com 5 ppm. A substituição de fonte inorgânica por fitase (500 ou 750 uf) na dieta não influencia o desempenho, as características de carcaça nem a composição mineral no osso de suínos alimentados com dietas contendo ractopamina.Palavras-chave: aditivos, β-adrenérgico, carcaça, enzima, fitato, osso Performance, carcass characteristics and bone composition of swines fed different levels of ractopamine and phytase ABSTRACT -The experiment was carried out aiming at evaluate the effect of using ractopamine and phytase in diets for swines at the end of the finishing period on performance, carcass characteristics and mineral composition on the third metacarpus bone. It was used 240 barrows with initial weight 100.7 ± 3.9 kg in a random block design, in a 2 × 3 factorial arrangement, with two levels of ractopamine (5 ppm and 10 ppm) and three levels of phytase (0, 500, and 750 FTU) totalizing six diets evaluated in five replications of eight animals per experimental unit. The experiment was conducted for three weeks and, at the end, the animals were slaughtered for carcass evaluation. There was no interaction among the levels of ractopamine and phytase for any of the variables. Body weight, ration daily intake, farm to slaughter shrink, percentage of fat-free lean and contents of ash, phosphorus and fluoride in the bone were not influenced by the diets. The level 10 ppm ractopamine promoted the best results of weight gain, feed conversion, hot carcass weight, total fat-free lean, payment index, and content of calcium in th...

Ractopamine for Pigs: A Review about Nutritional Requirements

“…However, it should be noted that according to the theory that supports the use of ractopamine; various nutrients are integrated in process of nutrient distribution in muscle and adipose tissues. Perhaps for this reason, researchers observed effects of phytase on the availability of phosphorus, but observed no effect of ractopamine in the diets of finishing pigs [2,22,[27][28][29]. Some of these researchers worked with animals weighing less than ideal and others with insufficient amounts of ractopamine, and they did not notice the need for supplementation of the diets with lysine and other amino acids, or the need for corrections of energy values.…”

“…Slaughterhouses, in order to increase industrial output, have preferred to process heavier pigs (between 115.0 and 130.0 kg). To match end user demand with supply of meat from the slaughterhouses, it has been proposed to use ractopamine in pig diets in the finishing phase (from 95.0 to 120.0 kg) while removing it from the diets at least ten days prior to slaughter [1][2][3].…”

“…Use of ractopamine to improve animal performance also demands larger quantities of other nutrients in the diet that participate in protein metabolism [9]. There is evidence that this ß-adrenergic has resulted in greater muscle tissue deposits but with lower bone mass deposits and this may be due to lack of calcium and especially phosphorus to increase muscle growth without bone loss [10], but little attention has been paid to this fact [2].…”

Ractopamine concentration on the lipid profile of swine fat and meat

“…The meat processing industry has sought lowerfat and higher-meat carcasses, rewarding producers with the most suitable carcasses, and consequently stimulating new nutritional strategies in the field (CORASSA et al, 2010). One way to improve production efficiency and pig carcass quality has been the use of different additives (CANTARELLI et al, 2009).…”

“…Ractopamine has been shown to effectively reduce carcass fat amount (APPLE et al, 2007;CANTARELLI et al, 2009;CORASSA et al, 2010), which has provided economic benefits (BRUMATTI & KIEFER, 2010). However, its qualitative effect on fat has not been extensively investigated; although, the fatty acid profile of swine fat is known to be modified through different diets (DURAN-MONTGÉ et al, 2010).…”