Effects of light conditioning on reproduction in partridge.

Reproductive response was measured in two lines of chukar partridge given conditioning light treatments of either 8 hr light:16 hr dark (8L:16D) at 50 lx or 16L:8D at .1 lx for 4, 6, or 8 weeks, respectively. Birds were recycled to lay using the same conditioning light treatments. During both lay cycles, all birds received 16L:8D at 100 lx. The results indicate that both conditioning light regimens were effective in terminating postjuvenile and postlay refractoriness. Hens given a conditioning light treatment of 8L:16D at 50 lx reached sexual maturity earlier, and produced more eggs and more viable chicks, and males maintained fertility longer, compared to birds conditioned under 16L:8D at .1 lx. Light conditioning periods of 6 and 8 weeks were superior to those of 4 weeks. For maximum reproductive performance in partridges, a short day photoperiod of 8L:16D at 50 lx is recommended for successful interruption of either postjuvenile or postlay refractoriness.