Combined supplementation of chromium-yeast and selenium-yeast on finishing barrows/Suplementagao associada de cromo-levedura e selenio-levedura na dieta de suinos machos castrados em terminacao

The present study was performed to evaluate the association of chromium-yeast and selenium-yeast as nutritional additives to enhance performance and quantitative characteristics in the carcass of finishing barrows. A total of 48 barrows, commercial hybrid, with initial weight of 68.3[+ or -]3.5 kg andfinal weight of 99.6[+ or -]3.6 kg, were utilizedfor the study. The animals were distributed in a randomized complete block design, consisting of three levels of chromium-yeast and selenium-yeast (i.e., without supplementation of chromium-yeast and selenium-yeast, supplementation of 0.4 mg [kg.sup.-1] chromium-yeast and 0.3 mg [kg.sup.-1] selenium-yeast, and supplementation of 0.8 mg [kg.sup.-1] chromium-yeast and 0.6 mg [kg.sup.-1] selenium-yeast) with eight replicates and two animals per experimental unit. The supplementation of chromium and selenium-yeast did not significantly affect (P>0.05) the average daily feed intake, digestible lysine, crude protein and metabolizable energy intake, average daily weight gain, feed conversion, weight and carcass length, back fat thickness, muscle depth, percentage and amount of lean meat, and carcass allowance. These findings suggest that supplementation of chromium and selenium-yeast does not affect the performance or quantitative characteristics in the carcass of finishing barrows. Key words: feed additives, carcass characteristics, organic minerals, performance, swine. Realizou-se este estudo com o objetivo de avaliar a associacao de cromo-levedura e selenio-levedura como aditivos nutricionais melhoradores de desempenho e das caracteristicas quantitativas de carcaca de suinos machos castrados em terminacao. Foram utilizados 48 suinos machos castrados, hibridos comerciais, com peso inicial de 68,3[+ or -]3,5 kg e peso final de 99,6[+ or -]3,6 kg. Os animais foram distribuidos em delineamento experimental de blocos casualizados, compostopor tres niveis de cromo-levedura e selenio-levedura (controle sem suplementacao de cromo-levedura e selenio-levedura; suplementagao de 0,4 mg [kg.sup.-1] de cromo-levedura e 0,3 mg [kg.sup.-1] de selenio-levedura; e 0,8 mg [kg.sup.-1] de cromo-levedura e 0,6 mg [kg.sup.-1] de selenio-levedura), com oito repeticoes e dois animais por unidade experimental. A suplementagao de cromo-levedura e selenio-levedura nao influenciou (P>0,05) o consumo de racao didrio, os consumos de lisina digestivel, de proteina bruta e de energia metabolizdvel, o ganho de peso didrio, a conversao alimentar, o p