The effect of frequency of insemination, dilution and dose rate of semen on the fertility of three breeds of chickens.

Abstract

Two factorial experiments were used to determine the effect of frequency of insemination and of dose and dilution rates on fertility in two and three breeds of chickens respectively. The semen used in both trials was obtained from a group of Synthetic breed cockerels. (The Synthetic breed was a closed population based on White Leghorn-Australorp crosses). In the frequency of insemination trial, White Leghorn and Australorp pullets were used. White Leghorns were more fertile than Australorps at both weekly and twice weekly inseminations (P<0.001). Australorp pullets had significantly higher fertility when inseminated twice a week compared to once a week (P<0.001). White Leghorn fertility improved to a far lesser extent with the more frequent inseminations. In the dose dilution trial, Australorp, Leghorn, and Synthetic pullets were used. With inseminations at once a week, over the three breeds, ninety per cent fertility was obtained when dose-dilution combinations provided between 0.03 and 0.04 ml of undiluted semen. Leghorns and Synthetics appeared to be more fertile than Australorps although the differences were not significant.