Mate choice in red-legged partridges (Alectoris rufa L.) kept in commercial laying cages; does it affect laying output?

In some gamebirds reared for shooting purposes, it has been demonstrated that free pairing and enriched environment may improve welfare. However, the effects of free pairing on the laying output of birds kept in commercial laying cages are poorly understood. Thus, the effects of free pairing on egg production were assessed in red-legged partridges (Alectoris rufa) kept in commercial laying cages (area of 0.45 m2 and volume of 0.18 m3). Between 2006 and 2007, we evaluated the laying output in two types of pairs: forced (n = 24), where one male and one female were randomly chosen, and free (n = 21), where the female chose between four males. Compared to forced pairs, free pairs laid the first egg 22 days earlier and 50% of the clutch was laid 11.6 days earlier. However, no significant differences in the quality of eggs or laying were found between forced and free pairs, resulting in length of laying of 76.5 days, clutch size of 39.5 eggs, 95.8% of fertility and 61.0% of hatchability of fertile eggs. Also, testosterone levels in eggs were not affected by the type of pair. We therefore recommend incorporating free pairing methods in commercial laying cages, as allowing natural reproductive behaviour has no negative effects on laying output and improves partridge welfare.