Authors:Barbara Végi, Éva Váradi, Zsuzsanna Szőke and Judit Barna
Since early fertility decline is a permanent problem of broiler breeders, the aim of this study was to test the effects of various sex ratios, spiking strategies and additional artificial inseminations (AI) on their breeding efficiency. Six breeder flocks were analysed during the whole reproduction cycle. In Flock A the sex ratio was maintained at 10% during the whole cycle (control), while in Flock B the number of males was increased to a final ratio of 16%. In Flocks C (technological control), D, E and F the ratio of males was gradually decreased from 10% to 6.5% until the end of the cycle. Moreover, at the age of 44 weeks in Flocks D and E 50 and 100% of cockerels were replaced by young ones, respectively, while in Flock F additional artificial inseminations were applied in the second half of the reproduction cycle. The increase of sperm transport was successful only in Groups B (increase in male numbers) and D (50% replacement of old cockerels with young ones); however, it was not sufficient for increasing the fertility rates in either group. Nor did additional artificial inseminations (Flock F) have an effect on fertility. As a conclusion, it can be established that increasing the sperm count in the hens’ oviducts in any way could not improve fertility in the last third of the production cycle. The results also suggest that the expensive and labour-intensive spiking technique used in broiler breeder management is useless. The prime factor responsible for the shortened persistence of fertility may be the reduced ability of the female oviduct to accept and store sperm.