Male mating behaviour and fertility of layer breeders in natural mating colony cages: LED light environmental effects

Abstract

Natural mating colony cages for parent-stock layer breeders, instead of conventional cages with artificial insemination, have been widely adopted by many commercial farms in China. However, the fertility rate of this system varies greatly among different cage tiers. We speculated that the difference in fertility rate might be caused by uneven illumination because vision appears to play a central role in birds’ behaviour, including mating. The objectives of this study were to investigate the effects of 4 LED light colours (white: WL, red: RL, yellow-orange: YO, and blue-green: BG), each at 2 light intensities (10 lx, 25 lx), on mating frequency and fertility for layer breeders in natural mating colony cages. A total of 32 identical cages were involved in the 8 treatments, with 4 replicates for each treatment and 5 males and 45 females per cage. The results showed significant effects of age, light colour, light intensity and colour-intensity interaction on the frequency of mating behaviour, integrity of matings and fertility. Overall, flocks treated with WL and RL and a higher light intensity during the laying period showed more frequent mating behaviour, a larger proportion of relatively complete matings and a higher fertility. All components of mating behaviour and fertility declined from 30 wks to 50 wks of age, but no significant correlation was found between fertility and mating behaviour. In summary, the results of this study illustrate that differences in LED light colour and light intensity influenced the mating behaviour and fertility of layer breeders. WL and RL and a higher light intensity can increase the frequency of mating behaviour, the proportion of complete matings and fertility. No significant correlation was found between fertility and mating behaviour. Such knowledge can help to understand mating behaviour in natural mating colony cages and provide a basis for optimization of the light environment.