A new poultry semen extender. 1. Effects of extension on the fertility of chicken semen.

Maximum extension of chicken semen in the Beltsville Poultry Semen Extender was determined by varying the dilution rate and the number of sperm per insemination. Levels of fertility were high (greater than 88%) in White Leghorn hens inseminated weekly with diluted (1:4) semen containing as few as 20 million sperm. The results also showed that (a) insemination intervals greater than 7 days resulted in a significant decline in fertility, (b) fewer sperm were needed in the insemination dose when diluted semen is held at 5 degrees C. than at 25 degrees C. and (c) high fertility levels (greater than 90%) can be achieved with semen diluted 1:10 provided the insemination dose contains at least 100 million sperm.