Crescimento e deposição de nutrientes nas penas, músculo, ossos e pele de frangos de corte de duas linhagens comerciais

Abstract

RESUMOConduziu-se este trabalho, com o objetivo de avaliar o perfil de crescimento e de deposição de nutrientes nas penas, nos músculos, nos ossos e na pele de machos e fêmeas de frangos de corte das linhagens Ross e Cobb, no período de 1 a 56 dias de idade. Foram utilizados 1920 pintos, alojados em boxes de um galpão experimental, em piso. O delineamento experimental foi inteiramente casualizado, fatorial (2 x 2), sendo 2 linhagens e 2 sexos, 4 repetições de 120 aves cada. As aves foram alimentadas com ração, formuladas para atender às exigências nutricionais das aves nas diferentes fases de criação. As aves foram abatidas semanalmente, após um jejum de 24 horas e, em seguida, foram depenadas, evisceradas e realizadas a separação dos ossos, da pele e dos músculos, estes foram pesados e armazenados em câmara fria. Após, foram moídos e liofilizados para realizar as análises laboratoriais. Os parâmetros de peso e de deposição de nutrientes obtidos semanalmente foram estimados em função da equação de Gompertz, e as taxas de crescimento por meio das derivadas das equações. Houve interação (P<0,05) entre linhagens e sexo para peso à maturidade (Pm) e idade de máximo crescimento (t*) do peso e proteínas das penas e Pm, b (taxa de maturidade) e t* de peso do músculo. O crescimento das penas foi mais tardio para as aves Cobb, contudo, a ave Ross foi mais tardia na taxa de crescimento de proteína no músculo. Os parâmetros para peso dos ossos e pele, foram semelhantes entre as linhagens estudadas.Termos para indexação: Avicultura, curvas de crescimento, Gompertz, músculo, ossos e pele. ABSTRACTThe objective of this work was to study the profile of growth and nutrient deposition on muscles, bones and skin of Ross and Cobb male and female broiler chicken from the age of one day to 56 days. We used 1920 chicks raised in experimental boxes. The experimental design was randomized in a factorial model (2 x 2), with 4 replications of 120 birds each. The birds were fed with diets formulated to supply the nutrient requirements according to each breeding phase. The birds were slaughtered weekly, after 24 hours of fasting, then they were completely plucked and feather samples were collected. The birds were eviscerated and after separating the skin and muscles from the bones, they were weighed, identified and stored in a cold chamber. Thereafter, the samples were ground and freeze-dried to be analyzed in laboratory. There was an interaction (P<0.05) between strains and gender for the parameters Pm and t* of the weight of plucked and fasting birds, water and body ashes, weight and feather proteins and Pm and t* for the muscle weight. Cobb strain was more precocious regarding growth and deposition of protein. The Pm of the muscle did not differ between the studied strains, however, Ross strain presented late growth rate of protein in the muscle and was precocious in the fat deposition rate. The parameters of the Gompertz equation were similar between strains for protein and skin weight.

Fiber level for laying hens during the growing phase

“…At sexual maturity, in addition to the proper body weight, birds need an ideal carcass composition because both appear to have an effect on egg weight (Neme et al, 2006). According to Marcato et al (2009), the potential for growth and tissue deposition are influenced by strain, sex, and growth stages, and as the birds grow older, there is naturally more body fat deposition, which is related to the relative maturity while the deposition of lean meat or protein is controlled by genetics.…”

Deposition of bodily chemical components in the carcass of tilapia (Oreochromis sp.) strains

“…In chickens, Marcato et al (2009) demonstrated that male Ross and Cob strains showed different rates in weight growth, which was probably the result of different rates of protein and fat deposition observed in this study for these strains. Working with laying birds, Neme et al (2006) also found differences between strains with regard to deposition rates of water, protein, fat and ash.…”

Carcass characteristics of broilers at 42 days receiving diets with phytase in different energy and crude protein levels

“…This variation in the results can be explained, in part, by genetic variability observed in the different research protocols (Marcato et al, 2009), different types of diet compositions and by amino acids, calcium and phosphorus levels in the diets (Silva et al, 2008), moreover the environment conditions. According to Fischer (1994), in conditions of nutritional deficiency, mainly of essential amino acids, the breast muscle can be affected.…”