Effect of feeding guanidinoacetic acid and L-arginine on the fertility rate and sperm penetration in the perivitelline layer of aged broiler breeder hens

Two experiments were conducted to evaluate the effects of feeding guanidinoacetic acid (GAA) and L-arginine (ARG) on fertility and sperm penetration (SP) rate of broiler breeder hens. In the first experiment, a total of 200 broiler breeder hens (Ross 308) aged 53week were randomly allotted to four dietary treatments (0, 0.6, 1.2 and 1.8g GAA/kg diet) with five replicates of 10 birds each. In the second experiment, 320 broiler breeder hens (Ross 308) were used from 53 to 62weeks of age in a 2x4 factorial arrangement (0 or 1.2g GAA/kg diet along with 0, 3, 6 or 9g ARG/kg diet). The hens received a diet containing 2800kcal ME/kg and 14% CP. Sixteen sexually mature Ross 308 breeder roosters (34weeks old) were used to artificially inseminate the hens. Fertility of the hens was determined in 61 and 62weeks of age. The sperm penetration holes in the inner perivitelline layer (IPL) overlying the germinal disc were enumerated on days 3 and 7 following each insemination. Adding GAA to the breeder diet increased the number of SPs in the IPL and fertility in both experiments (p<0.01). The interactive effect of ARG and GAA on the SP and fertility was significant. Supplementary ARG increased the SP rate in the IPL (p<0.01). In conclusion, dietary supplementation of GAA and ARG might be potentially used to improve the fertility of broiler breeder hens at the later phase of the egg production period.