Efeito de genótipo e do sistema de criação sobre o desempenho de frangos tipo caipira

Abstract

RESUMO -Este estudo avaliou a influência de genótipos e do sistema de criação sobre o desempenho de frangos de corte tipo caipira. Foram utilizadas duas linhagens experimentais (Caipirinha e 7P) e duas comerciais (Label Rouge e Paraíso Pedrês) criadas nos sistemas intensivo e semi-intensivo (acesso a piquete com gramínea após 21 dias de idade), em um experimento no delineamento em faixas com oito tratamentos, quatro repetições e 35 aves por unidade experimental. Ração à base de milho e farelo de soja e água foram fornecidas ad libitum, na área interna apenas, e as aves do sistema semi-intensivo tiveram livre acesso à área de pastejo. Cada unidade experimental foi criada até atingir o peso médio de 2300 g. Foi detectada interação linhagem x sistema de criação na variável idade para atingir 2300 g (idade 2300) e ganho de peso médio diário, sendo que a linhagem Caipirinha criada no sistema semi-intensivo teve Idade 2300 aumentada (79,2 dias vs 73,2 dias). Não houve diferença na Label Rouge (84,0 dias vs 62,2 dias) e Paraíso Pedrês (60,8 dias vs 61,0 dias). O consumo de ração (5688 g) e a conversão alimentar (2,46) das aves Label Rouge diferiram das demais (consumo de 4304 a 4996 g e conversão de 1,87 a 2,13), e o sistema de criação não afetou essas variáveis. A mortalidade não foi afetada pelas linhagens ou sistema de criação. O acesso à pastagem no sistema semi-intensivo não representou economia de ração ou melhoria na conversão alimentar, mas resultou em redução no ganho diário de peso da linhagem Caipirinha, provavelmente em razão de sua maior permanência no piquete.Palavras-chave: desempenho, frango tipo caipira, sistema de criação Effect of Genotype and Rearing System on Performance of Alternative Lines of Broiler ChickensABSTRACT -The present study evaluated the influence of genotype and rearing system on the performance of alternative lines of broiler chickens. Two experimental lines (Caipirinha and 7P) and two commercial lines (Label Rouge and Paraíso Pedrês) were reared under intensive or semi-intensive (access to the pasture area after 21 d of age) in an experiment with eight treatments, four replicates and 35 birds per experimental unit. Corn-soybean meal based feed and water were offered ad libtum in the pen area only, and the chickens in the semi-intensive system had free access to the pasture area. The experiment was terminated when each pen reached 2300 g of average weight. Interaction line x system was detected for variable age at 2300 g (Age 2300) and average daily weight gain; the line Caipirinha on the semi-intensive had Age 2300 increased ( (5688 g) and feed conversion (2.46) for the Label Rouge broilers were different from the others (feed intake from 4304 to 2996 g and feed conversion from 1.87 to 2.17), and rearing system affect these variables. Mortality was not affected by genetic lines or rearing system. The access to pasture in the semi-intensive system did not result in feed economy or improvement in the feed conversion, but resulted in reduction on the daily weight gain (as a consequenc...

Results of Rearing Broiler Chickens Under Various Systems

“…With reference to this, proportions of main carcass parts (breasts, thighs and drumsticks), as well as presence of particular tissues in them, are considered to be significant parameters defining broiler meat quality (Lewis et al, 1997;Suto et al, 1998;Holcman et al, 2003;Ristic, 2003). The above mentioned quality traits depend on many biological factors, among others, on the genotype, sex and age (Lewis et al, 1997;Bokkers & Koene, 2003;Hellmeister et al, 2003;Sogunle et al, 2010). Among numerous non-genetic factors, the most important role plays broiler nutrition.…”

The effect of sex and rearing system on carcass composition and cut yields of broiler chickens

“…The above-mentioned quality traits depend on a number of factors. Of the biological ones, the greatest impact is produced by genotype, sex and age (Lewis et al, 1997;Bokkers and Koene, 2003;Hellmeister et al, 2003).Among numerous non-genetic factors that may have a considerable effect on meat quality, a broiler rearing system has been recognised over the past years by a large number of authors as being particularly important (Lewis et al, 1997;Bokkers and Koene, 2003;Hellmeister et al, 2003;Ristic, 2003). …”

“…Among numerous non-genetic factors that may have a considerable effect on meat quality, a broiler rearing system has been recognised over the past years by a large number of authors as being particularly important (Lewis et al, 1997;Bokkers and Koene, 2003;Hellmeister et al, 2003;Ristic, 2003). …”

“…The above-mentioned quality traits depend on a number of factors. Of the biological ones, the greatest impact is produced by genotype, sex and age (Lewis et al, 1997;Bokkers and Koene, 2003;Hellmeister et al, 2003).…”

Effects of labor motivation in poultry production

“…Animal welfare has become a public concern, and it may lead to misconceptions of values and productivity (Heier et al, 2002;Hellmeister et al, 2003;McInerney, 2004). Cransberg et al (2002) studied the influence of labor on the behavior and productivity of broilers, and found that the manner stockpeople moved around the house (speed of movement) was positively correlated with flock mortality during the first rearing weeks.…”