Mating behavior and fertility of broiler breeder males reared on shortened growth cycles

SUMMARY One of the more difficult tasks when raising broiler breeder cockerels is controlling BW gain in the rearing house without inflicting excess stress. This is a period of time for the young male when many portions of the reproductive system are in the formative stages and, if neglected, can have lifelong effects on their reproductive performance. The objective of this study was to raise males under feed management programs that produced the recommended target BW of 3,060 g for males at 12, 15, 18, 21, and 24 wk of age. Males were placed at 3-wk intervals so that all males with the same BW were light stimulated at the same time but at different ages. All males were reared in the same light-controlled house at the University of Arkansas Research Farm. Males were light stimulated, and testes development, complete semen analysis, fertility, and mating activity and behavior were recorded for each group of males. At the time of light stimulation, the younger males were less successful at completing matings, crowed less often, and showed less wing flapping and neck flaring than older males, based on the results for mating behavior. Males that were older at the time of light stimulation had higher fertility than younger males. Males that were 24 wk old at the time of light stimulation had an overall fertility of 94.5%, compared with 91.8, 91.6, 79.2, and 87.3%, respectively, for the other ages. In this study, we found that males that were exposed to light at earlier ages exhibited less overall mating activity than older males.