Growth curves, body nutrients deposition and determination of protein requirement for light and semi heavy hen pullets

Growth curves of pullets were adjusted to describe the deposition rates of body components and estimate the requirements in protein. Altogether 1500 poultry were randomly distributed in 30 repetitions of 25 birds. The experimental period was divided into four stages (1 to 4 weeks 5 to 11 weeks and 12 to 16 weeks old). The rations formulated based on corn and soybean meal were offered the will. Weekly, pullets were heavy and two birds separates by lineage to be in determining chemical composition of body nutrients. The informations was used to obtain the parameters of the Gompertz model. Allometric relationships were used to describe the changes in body composition in protein, lipid, ash and water in the body gutted and without feathers. The data of body weight growth of the strains pullets Dekalb White and Bovans Goldlina fit to the Gompertz function. The allometric coefficients of fat, water and mineral matter on the basis in proteic weight of the lines Dekalb and Bovans lines were respectively: 0.114 vs 1.160; 0.811 vs 0.429; 0.930 vs 0.189. There are differences among genotypes for growth rates and deposition of body nutrients and fearther. The light-line is earlier. The total protein requirements (maintenance and gain) for pullets of 1 to 4, 5 to 11 and 12 to 16 weeks of age were respectively 4,41; 9,814; 12,612 g / d for Dekalb White and 4.82; 8,859; 7,673g / d to Bovans Goldline. The aim of this work was to determine growth curves and body nutrients deposition by using Gompertz equation, and to estimate protein requirement in light and semi heavy hen pullets. In total, 1,500 hen pullets were distributed at random into 30 repetitions of 25 birds each. Experimental period was divided into three steps (1st to 4th, 5th to 11th and 12th to 16th weeks of age). Rations were formulated based on corn and soybean meal and offered ad libitum. Birds were weighed weekly. Two birds per repetition were used to determine chemical body composition and data were used to obtain Gompertz model parameters. Allometric ratios were used to describe changes in the body composition in protein, lipid, mineral matter and water in the eviscerated and featherless body. Weight-age data of Dekalb White and Bovans Goldline pullets were well described by Gompertz function. Allometric coefficients of fat, water and mineral matter in function of the protein body weight were, respectively: 0.114, 0.811 and 0.930 for Dekalb line and 1.160, 0.429 and 0.189 for Bovans line. There are differences between lines for growth rates and body nutrients and feathers deposition, with Dekalb line being the most precocious. Total protein requirements (maintenance and growth) for pullets from 1st to 4th, 5th to 11th and 12th to 16th weeks of age were 4.41; 9.814 and 12.612 g˙d-1 for Dekalb White and 4.82; 8.859 and 7.673 g˙d-1 for Bovans Goldline, respectively

NÍVEIS DE PROTEÍNA PARA FRANGAS SEMIPESADAS NO PERÍODO DE UMA A DEZOITO SEMANAS DE IDADE

Desenvolveram-se dois experimentos com o objetivo de avaliar diferentes níveis dietéticos de proteína bruta para frangas semipesadas. No primeiro experimento, as aves com dois dias de idade foram alimentadas até seis semanas com dietas contendo sete níveis de proteína (14%, 15%, 16%,17%, 18%, 19% e 20%) e com 3,0 Mcal de EM. No segundo experimento, a alimentação das aves constitui de dietas contendo quatro níveis de proteína (14%, 15%, 16% e 17%) e 2,9 Mcal de energia metabolizável da sétima a décima oitava semana. Após esse período, avaliou-se o desempenho produtivo dessas aves, no período de vinte e seis a trinta e oito semanas de idade. De uma a seis semanas de idade, o nível de 20% de PB proporcionou melhor desempenho. No segundo experimento, houve efeito significativo para o consumo de proteína e ganho de peso (efeito linear crescente) e efeito linear decrescente para conversão alimentar e eficiência protéica. Os níveis de proteína na fase de recria não influenciaram as variáveis avaliadas na fase de produção. Apenas houve efeito linear crescente para peso da casca. Com isso pode-se concluir que, para o período de sete a dezoito semanas de idade, a utilização de um nível de 14% de proteína bruta não afeta o desempenho das aves na fase de produção. PALAVRAS-CHAVES: Aves, cria, produção de ovos, recria e qualidade do ovo