Arquivo Brasileiro de Medicina Veterinária e Zootecnia (Aug 2007)
Efeitos da forma física da ração sobre a digestibilidade dos nutrientes e desempenho de frangos de corte Effects of physical form of ration on feed digestibility and performance of broiler chickens
Abstract
Compararam-se os efeitos da forma física da ração sobre a digestibilidade de nutrientes e o desempenho de frangos de corte. No primeiro experimento foram utilizadas 480 aves (machos) da linhagem Ross-308, de 1 a 42 dias de idade. O delineamento experimental foi inteiramente ao acaso com três tratamentos (farelada, granulada e expandida-granulada), com oito repetições de 20 aves. No segundo, utilizaram-se 900 aves da mesma linhagem, sexo e período de criação segundo o mesmo delineamento experimental, mas com 10 repetições de 30 aves cada. O coeficiente de metabolização da matéria seca não foi afetado pelos tratamentos. A proteína metabolizável foi maior na ração expandida granulada do que a farelada (PTwo experiments were carried out in order to compare the effects of physical form of ration on feed digestibility and performance of broiler chickens. In the first experiment 480 day-old male Ross broiler chicks were used during the 42 days of trial, following a completely randomized design of three treatments: three physical forms of ration (mash, pellet and expanded-pellet) with eight replicates of twenty birds each. In the second experiment 900 day-old male Ross broiler chicks were used during the 42 day of trial, following the same design, but with 10 replications of 30 birds each. No significant difference in the coefficient of dry matter metabolization was observed. The metabolizable protein was higher in pellet-expanded ration and lower in mash ration (P<0.05). The processing of diet significantly increased the metabolizable ether extract (P<0.05) and values of 68.87, 74.64 and 74.44% were observed for mash, pellet and expanded-pellet rations, respectively. Body weight of broilers increased as the intensity of processing of ration reaching 2.597, 2.828 and 2.874kg for mash, pellet and expanded-pellet rations, respectively (P<0.05). Birds fed processed rations showed higher feed consumption and lower feed conversion (P<0.05). The physical form of ration did not affect viability of birds.
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