Optimizing delivery of genetic merit in subtropical climates through advanced reproductive technologies.

The poultry industry in subtropical climates faces the challenges of climate and variable feed quality, in addition to those challenges encountered in temperate zones. These challenges aggravate the problem associated with the progressive decline in reproductive performance due to genetic selection for growth and yield traits. Heat stress is the major cause of lower fertility in both males and females, regardless of age. Under such situations, nongenetic factors play critical roles in maintaining or increasing reproductive efficiency in broiler breeders. The relatively low cost of skilled labor in subtropical countries enables consideration of artificial insemination for hens in cages or on the floor as an alternative to conventional floor mating, and also identification and culling of males producing few sperm or sperm of inferior quality. Artificial insemination allows extended use of superior males and setting up rooster stud farms. Such operations, plus selection for economic growth and carcass traits in pedigree lines known to tolerate the climate, will be important for continued growth of market share.