|Institution:||Oregon State University|
|Keywords:||Poultry – Breeding|
|Full text PDF:||http://hdl.handle.net/1957/47383|
Hens were artificially inseminated at 8:00 a.m., 4:00 p.m. and 11:50 p.m. Fertility was found to be significantly lower after 8:00 a.m. inseminations than after 4:00 p.m. or 11:50 p.m. inseminations for 2 to 6 days, 2 to 9 days and 10 to 17 days following inseminations. Slightly higher fertility resulted after inseminations at 4:00 p.m. than after 11:50 p.m. inseminations for 2 to 6 days and 2 to 9 days following inseminations; however, the differences were not statistically significant. Fertility for 10 to 17 days following insemination was significantly higher when inseminations were made at 11:50 p.m. than at 8:00 a.m. or 4:00 p.m. Duration of fertility was longest after the 11:50 p.m. inseminations. Only after the 8:00 a.m. inseminations were there hens with zero fertility. Fertility as influenced by time of oviposition following insemination was also studied. Reduced fertility resulted when hens were inseminated 1 to 4 and 23 to 28 hours prior to oviposition. The incidence of hens with zero fertility also was greater when hens were inseminated 1 to 4 hours before oviposition. Those hens laying within four hours after insemination had a hard-shelled egg in the uterus at the time of insemination; and many of those laying within 23 to 28 hours after insemination had an egg in the magnum, were ovulating or approaching ovulation. Decreased fertility associated with the last four hours of shell secretion, with the approximate time of ovulation, and with the presence of an ovum in the magnum appears to account for much, if not all, of the difference in fertility following morning inseminations and following afternoon or evening inseminations. The procedure of artificial insemination was not more difficult when a hard-shelled egg was in the uterus than at other times, since no relationship was found between the difficulty of everting the vagina or inserting the inseminating syringe and the presence of a hard-shelled egg in the uterus.