Influence of mating sex ratio in commercial pheasant flocks on bird health and the production, fertility, and hatchability of eggs

Abstract

1. The effects of two mating ratios (8 : 1 and 12 : 1 females : males) on bird health, egg production and quality, fertility (employing macroscopic and microscopic techniques) and hatchability were examined for pheasants ( Phasianus colchinus ) on a commercial game farm, to provide a baseline data set for production of pheasants under specific conditions. 2. Mating ratio did not significantly affect mortality or pathology of breeding birds. 3. Egg production was significantly higher for the 8 : 1 mating ratio over the first 5 weeks of the trial but this difference disappeared during the second half of the trial. 4. Incidence of rejected eggs increased as the season progressed, mainly due to poor shell quality, but it was not significantly affected by mating ratio. 5. Fertility of eggs produced from birds under an 8 : 1 mating ratio was consistently and significantly 4% higher than fertility of eggs from the 12 : 1 mating ratio. The incidence of eggs showing no sign of mating (no sperm) was twice as high for the 12 : 1 pens (13.7% of the sample). There was good agreement between macroscopic and microscopic examination of fertility in eggs. Higher fertility in the 8 : 1 pens appeared to be related to a higher proportion of the females being recruited and mated. 6. Hatchability was significantly improved by adopting an 8 : 1 mating ratio, presumably due to the higher fertility of the eggs. Candling of the eggs improved hatchability but only for the 12 : 1 pens probably because more clear eggs were removed from the tray.