Early exposure to the opposite sex affects mating behaviour in White Leghorn chickens

To examine the effect of early exposure to the opposite sex on mating behaviour in White Leghorns we observed interactions between males and females that had been raised with (mixed-sex) or with-out (same-sex) the other sex. Groups of six females and one male were assigned to one of four treatments based on how they were raised: mixed-sex females with a mixed-sex male (MM), same-sex females with a same-sex male (SS), mixed-sex females with a same-sex male (MS) and same-sex females with a mixed-sex male (SM). Observations were conducted over an 8-week period beginning when the birds were 23 weeks old. Overall, MM and SS groups had significantly more successful copulations and a higher success rate than MS and SM groups, although the increased rate was mostly because of the influence of the MM group. Female behaviour was similar among treatment groups, although more mating attempts and more successful copulations occurred with top-ranking females in the MM and SS groups. Finally, MM and SS groups initially produced more eggs than the MS and SM groups, however, this difference disappeared over time. The results of this study show that early experience with the opposite sex enhances mating success in adulthood. However, it also indicates that matching males and females for experience is of importance.