科研之友
微信
新浪微博
Facebook
分享链接
摘要
A cria o intensiva de frangos de corte, aliada 角 nutri o e ao melhoramento gen谷tico com foco no ganho de peso, tem resultado em 赤ndices crescentes da incid那ncia de problemas de pernas. Dentre as vari芍veis que podem contribuir para a ocorr那ncia destes problemas, est o a linhagem e o sexo. Neste contexto, avaliaram-se propriedades geom谷tricas e mecanicas de t赤bias de frangos de corte, machos e f那meas, de tr那s linhagens comerciais no periodo final de crescimento, entre 21 e 42 dias. As caracter赤sticas geom谷tricas refletem a resposta adaptativa dos ossos, com rela o direta entre suas dimens es e o peso vivo das aves. Quanto 角s caracter赤sticas mecanicas obtidas de ensaios de flex o, observa-se o que o julgamento da robustez 車ssea pode levar a conclus es diferentes dependendo da vari芍vel mecanica considerada. Aves mais pesadas, com ossos maiores, suportam for as maiores na flex o. Entretanto, quando vari芍veis de resist那ncia intr赤nsecas do material s o consideradas, como resist那ncia 角 flex o, observa-se que a linhagem mais pesada n o apresenta resist那ncia 角 flex o significativamente diferente das demais. O mesmo ocorre entre machos (mais pesados) e f那meas. Logo, aves mais pesadas, com t赤bias t o resistentes quanto 角s das aves mais leves, podem ser mais suscept赤veis a problemas estruturais de pernas. The intensive rearing of broilers, combined with nutrition and genetic improvement focused on weight gain has resulted in increasing rates of leg problems. Among the variables that may contribute to the occurrence of these problems are sex and lineage. In this context, the study evaluated the geometric and mechanical properties of the tibiae of broilers, male and female, from three commercial lines in the final growth stage, between 21 and 42 days. The geometric characteristics reflect the adaptive response of bone, with a direct relationship between their dimensions and the live weight of birds. As for the mechanical properties obtained from bending tests, it isobserved that the evaluation of bone strength can lead to different conclusions depending on the mechanical parameter considered. Heavier birds, with larger bones, support more load in bending. However, when intrinsic strength parameters of the material are considered, such as bending strength, it is observed that the heavier line does not showsignificantly different values from the others. The same occurred among males (heavier) and females. Thus, heavier birds may be more susceptible to structural leg problems, as their tibias are as strong as those from lighter birds.
