Ciência e Agrotecnologia (Jun 2009)
Crescimento e desempenho de linhagens de aves pescoço pelado criadas em sistema semi-confinado Growth and performance of naked neck broiler reared in free-range system
Abstract
Este trabalho foi realizado para avaliar o crescimento e desempenho de duas linhagens de aves pescoço pelado. Foram utilizadas 400 aves, distribuídas em um delineamento inteiramente casualizado, os tratamentos consistiram de um esquema fatorial 2 x 2 (linhagens x sexo), com cinco repetições de 20 aves cada. Foram utilizadas aves Pescoço Pelado das linhagens Sasso e ISA Label. As aves receberam rações formuladas à base de milho e de farelo de soja para atender às exigências nutricionais. Foi determinado o ganho de peso (GP), o consumo de ração (CR) e a conversão alimentar (CA) aos 28, 56 e 84 dias de idade e o rendimento de carcaça e de partes aos 84 dias de idade. Não foi observada interação entre sexo e linhagem (P>0,05) para nenhuma das variáveis de desempenho analisadas. Para CR e GP houve diferenças significativas (PA trial was carried out to evaluate the growth and performance of naked neck birds. Four hundred birds were distributed into four treatments in factorial arrangement (2 strains x 2 genders), with five replicates of 20 birds each. The naked neck strains evaluated were Sasso and ISA Label. The birds were fed a diet formulated with corn and soybean meal according to the nutritional requirements. Food intake, body weight gain and food conversion were determined at 28, 56, and 84 days as well as the yield of carcass and cuts at 84 days. No interaction was observed between gender and strain (P>0.05). Food intake and body weight gain were different (P <0.05) between the strains and between the genders. Sasso strain presented higher performance than ISA Label. The parameters estimated for Gompertz equation, the weigh at maturity (Wm) and time that the growth rate is maximum (t*) were higher and maturity rate (b) was lower for Sasso strain than those of Isa Label strain. These results indicated that the Isa Label was more precocious than Sasso strain. The females showed better breast yield while the males showed better thigh and drumstick yield.
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