Reproductive Performance in Aged Partridge

Various reproductive traits were studied in three groups of Red-legged partridge, 72, 60, and 18 months of age, that were mated in all possible age-combinations for two 10-week production periods. Between periods of lay, the males were switched among the females within each age group. The two oldest groups of birds had been held previously under either a stimulatory (16L:8D) or nonstimulatory (8L:16D) light treatment, respectively, from hatch to 48 months of age. Sexual maturity, egg production, fertility, and hatchability were determined. Egg production and fertility were significantly lower in the two oldest groups as compared to younger birds. Major differences in several reproductive traits were found between the two oldest groups. It is suggested that the normal response to photostimulation is altered in birds exposed to long periods of non-stimulatory light, resulting in a decrease of productivity during later periods of life.