<b>Digestible lysine for broilers from different commercial strains in the final phase

Abstract

ABSTRACT. This study aimed to evaluate different digestible lysine levels in diets for broilers chickens from different commercial strains, from 49 to 56 days of age, on performance and carcass characteristics. A total of 432 male broilers from 49 days old were used, with an average weight of 3560±250 g. It was used a completely randomized design in a factorial arrangement 3x4, and the birds, from three strains (Cobb 500, Hubbard Flex and Ross 308) were divided into four levels of digestible lysine (0.800, 0.950, 1.100 and 1.250%), with four replicates of 12 birds each. It was evaluated the weight gain, feed intake, feed conversion ratio, carcass yield, breast yield, breast meat yield and the yield of the thigh and drumstick. There was no interaction between lysine levels and commercial strains of broiler chickens. The different lysine levels did not influence (p ≥ 0.05) performance and carcass yield. There are significant differences between strains for feed intake and carcass characteristics. The Cobb 500 strain had higher breast yield and breast meat (p < 0.05), while the Hubbard Flex and Ross 308 strains had higher yield of the thigh and drumstick (p < 0.05).Keywords: amino acids, breast meat, performance, genotypes, carcass yield.Lisina digestível para frangos de corte de diferentes linhagens na fase final de criação RESUMO. Objetivou-se avaliar diferentes níveis de lisina digestível em rações para frangos de corte de diferentes linhagens comerciais na fase de 49 a 56 dias de idade sobre o desempenho e características de carcaça. Foram utilizados 432 frangos de corte machos de 49 dias de idade, com peso médio inicial de 3560±250 g. Utilizou-se o delineamento inteiramente casualizado em arranjo fatorial 3x4, sendo que as aves, oriundas de três linhagens (Cobb 500, Hubbard Flex e Ross 308), foram distribuídas em quatro níveis de lisina digestível (0,800; 0,950; 1,100 e 1,250%), com quatro repetições de 12 aves cada. Avaliou-se o ganho de peso, o consumo de ração, a conversão alimentar, o rendimento de carcaça, o rendimento de peito, o rendimento de carne de peito e o rendimento de coxa e sobrecoxa. Não houve interação entre os níveis de lisina digestível e as linhagens comerciais de frangos de corte. Os diferentes níveis de lisina não influenciaram (p ≥ 0,05) o desempenho e rendimento de carcaça. Existem diferenças significativas entre as linhagens para consumo de ração e características de carcaça. Sendo que a linhagem Cobb 500 teve maior rendimento de peito e carne de peito (p ≤ 0,05), enquanto as linhagens Hubbard Flex e Ross 308 tiveram maior rendimento de coxa e sobrecoxa (p ≤ 0,05).Palavras-chave: aminoácido, carne de peito, desempenho, genótipos, rendimento de carcaça.

Performance, Growth Curves and Carcass Yield of Four Strains of Broiler Chicken

“…When evaluating the cut yields of broiler chicken strains, some studies (Api et al, 2017;Dalólio et al, 2016) observed greater breast yield for Cobb strain and greater drumstick yield for Hubbard, results similar to the present study. The yield results of edible viscera and feet are presented in Table 6.…”

“…Males of the Ross strain had FI, WG and FC higher than chicken from the other strains (p<.005), differently from other studies that did not show differences among the strains for FC at the end of raising (Api et al, 2017;Peak et al, 2000;Stringhini et al, 2003). Dalólio et al (2016) evaluated levels of digestible lysine in the final phase of the raising of three broiler chicken strains and observed that the chickens of the Cobb 500 strain had higher FI than the strains Hubbard Flex and Ross 308 but did not differ in WG and FC.…”

Protease Supplementation under Amino Acid Reduction in Diets Formulated with Different Nutritional Requirements for Broilers

“…Besides that, one of the main factors is the level of digestible lysine in the diet as all other limiting amino acids are calculated as a function of lysine. Thus, when there is an unbalance of a certain digestible amino acid, namely lysine, there are deamination and transamination reactions with donation and/or degradation of its respective amino groups, moving the amino acid function to other functions such as excretion of its metabolism products (Dalólio et al 2016). Rodrigues et al (2008) claim that the digestible lysine:crude protein ratio in the diet is very important and should be maintained around 5.90% until 42 days.…”