Paper Information

Background and Objective: Reproduction in poultry has been studied for many years and is a crucial factor to consider when selecting and raising parental lines. Considerable work has focused on broiler breeder males, which has led to the development of feed restriction practices, as well as sex separate rearing, however very little research has been done on layer-type males. In broiler breeders a negative correlation has been found to exist between the Body Weights (BW) and sexual activity of the male. This study was conducted to explore the role of diet during grow out on reproductive traits in leghorn type males. Materials and Methods: Hyline parent stock males were raised on 3 different diets Low (12% CP) Control (18% CP) and High (24% CP). As birds reached sexual maturity, Body Weight (BW), testis size, semen volume, sperm concentration and histology were measured. Results: This trial demonstrated significant (p<0.0001) differences in body weights between the diets. The mean BW of birds were 1214.87, 1435.41 and 1475.96 g fed on the Low diet, control and high diet, respectively. There were significant differences observed in testicle weights. The Low group had a significantly lower mean weight as compared with Control and High groups. Differences in semen volume were observed between the dietary treatment groups, as well as, differences in sperm concentrations at 18-20 weeks of age. Significant differences in development were seen between High and Low groups upon histological examination and scoring on a 0-6 scale, 0 = Immature (no spermatozoa) to 6 = Fully mature (spermatozoa present in all tubules) of the testes high (3.9) low (1.2). Conclusion: These results suggest that feeding high nutrient dense diets during rearing does not result in a decrease in production as observed in broiler breeder males and that low nutrient diets are not as beneficial in layer males as in broiler breeder males.