Improved effectiveness of artificial insemination of turkey hens associated with ahemeral light-dark cycles and age at photostimulation.

In lighting studies with turkey hens, long ahemeral (AH; non-24 h) light-dark cycles have consistently resulted in greater, although not statistically significant, fertility than control 24 h light-dark cycles. The present study was designed to further evaluate AH lighting effects on fertility by an evaluation of the effectiveness of artificial insemination (AI) under less than optimal conditions for normal fertility, that is, single AI and early age at lighting. Turkey hens had greater percentage fertility of eggs when photostimulated at 30 wk (95.0) than 26 wk (76.3) of age following single, but not double, AI. Ahemeral lighting dramatically improved the effectiveness of a single AI of hens photostimulated at 26 wk of age as compared to controls (89.3 vs 76.3% fertility, respectively). However, with multiple AI, benefits of AH lighting on fertility exceeding that of control hens was not significant. It may be concluded that AH lighting can dramatically improve the effectiveness of AI under certain adverse conditions, such as early age at lighting and reduced exposure of the hen to sperm.