Measuring growth and evaluating reproductive performance of commercial broiler-breeder pullets fed on varying growth curves.

摘要

Maximizing the reproductive efficiency of broiler-breeders has long been a challenge for broiler companies. Broiler-breeder production is maximized by properly rearing the bird and keeping it reproductively fit by preventing it from becoming overweight. In order to properly control the body composition of broiler breeder pullets, managers need a way to measure the development and growth of these broiler breeder pullets. One experiment in this thesis studied different ways of accurately measuring body composition and sexual maturity of broiler breeder pullets. This study compared many different techniques of measuring pullets to body weight, which is the original tool for measuring development of broiler breeder pullets. This study showed that body weight is still an adequate tool for assessing broiler breeder pullet body composition and sexual development.;Properly feeding broiler breeder pullets is also another way that broiler breeder reproductive performance can be maximized. There have been many attempts over the years to determine the optimum feeding regimen. This thesis also includes a study involving four treatment groups of Cobb 500 fast feathering birds fed on varying growth curves or fed varying energy levels. Two treatment groups were reared on a modified growth curve which restricted weight gain early in the rearing period and accelerated weight gain late in the rearing period. The other two groups were reared on a liear growth curve which allowed even weight gain throughout the rearing period. After rearing, the groups were moved from a pullet rearing house into a production house were eggs were collected and sent to a commercial hatchery. Residue breakouts were conducted periodically throughout the trial and hatchability, fertility, and egg production were compared between treatment groups. No significant differences in hatchability or fertility were recorded between any treatment groups; however the modified growth curve-low calorie diet treatment group did produce significantly fewer eggs.