Date of Graduation

12-2015

Document Type

Thesis

Degree Name

Master of Science in Poultry Science (MS)

Degree Level

Graduate

Department

Poultry Science

Advisor

R. Keith Bramwell

Committee Member

Fred D. Clark

Second Committee Member

Harold L. Goodwin

Abstract

Modern broiler breeders have been observed displaying significantly less mating behaviors than their ancestral fowl. Effective mating behavior translates into fertile hatching eggs that ultimately become broilers processed for market. The poultry industry has made significant changes in genetics, environment, housing, and diets of commercial poultry. However, there are some concessions made in genetic selection and streamlined management to produce larger, fast-growing, efficient birds. Aggression in broiler breeder males is believed to be a sign of high fertility. However, highly aggressive males pose a threat to the welfare of their flock mates, and may also impede frequency of mating and actually lower flock fertility. With improvements in efficiency of broiler breeders and their offspring, hatching of fertile eggs has become entirely mechanized to allow for incredible egg volumes to be incubated in a single facility. Some eggs may need to be stored for long periods of time, hatcheries are forced to set eggs from pre- and post-peak production flocks, or eggs laid on the floor area of the breeder house. These common management practices can pose potential threats to the developing embryo, and the performance of the subsequent chicks.

Frequency of mating behavior may be genetic strain-dependent, as observed by some integrators. Therefore, a study was developed to record and analyze the behaviors of two different strain crosses of broiler breeders in a commercial setting. This study differs from those previously conducted because the subjects were reared in commercial broiler breeder houses. In a second study, embryo integrity modifications are known to alter embryo development and have significant effects on hatchability, chick quality, and performance. A study was developed to test the effects of prolonged egg storage, broiler breeder flock age, and location of oviposition on hatchability, 14-day livability, and performance.

It was concluded that there were significant differences in aggression for one strain cross of broiler breeders. More studies with different crosses should be conducted in order to give conclusive evidence to the industry. As expected, egg storage and flock age had some significant effects on hatchability and growth performance. However, no differences were determined for location of oviposition.

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