The effects of lighting programs on reproductive performance of turkey males. IV

130-day-old [male][male] of the Quebec line were subjected to 6 lighting treatments from 5 wk of age. The percentage of [male][male] producing semen was significantly affected by light regime. Under 12-h light; 12-h darkness (12L:12D) with constant intensity (10.8 lux) or increasing intensity (5.4-54.0 lux), the percentage of [male][male] producing semen was 71.7 vs. 71.3 for [male][male]under other regimes (12L:12D and decreasing intensity, 16L:8D and constant intensity, 16L:8D and increasing intensity, and 16L:8D and decreasing intensity). Under 16L:8D and increasing intensity, the percentage of [male][male] producing semen (53.2) was significantly lower than under constant light intensity (73.4). The 12:12D regime with increasing intensity resulted in the highest semen volume (0.20 ml). Light regime had no effect on sperm concentration. The highest fertility was observed under 12L:12D with constant or increasing intensity (82.9 and 83.9% resp). It was concluded that lighting programmes of 12L:12D with a constant intensity of 10.8 lux yielded the best overall reproductive performance, followed by 12L:12D with increasing itensity (5.4-10.4-54.0 lux)..