Sperm-egg interaction assay for determination of fertile period in ostrich (Struthio camelus)

Sperm-egg interaction assay for assessment of fertile period in ostrich was carried out. A total of 24 hatching eggs collected from four female ostriches aged six years were used for this study. Significantly (P<0.01) higher number of Inner Peri-vitelline Layer (IPVL) sperm holes (18.56/mm²) was observed in the 1^st egg, which was laid on 2^nd day after last mating. Subsequently, the number of IPVLsperm holes on eggs laid on 3^rd, 4^th and 5^th day after last mating gradually decreased and the values were 16.66/mm², 13.03/mm² and 10.27/mm² respectively. Initial number of IPVL-sperm holes after last mating and rate of sperm holes decline was demonstrated using a simple regression and the relationship was expressed by the linear equation as Y= -2.85 × + 24.60 (R²=0.987). From the equation it was concluded that the number of IPVL-sperm holes declined at the rate of 2.76/mm² per day and expected to have 1.97 IPVL-sperm holes/mm² on 8^th day in the germinal disc (GD) after last mating. Similarly, Outer Perivitelline Layer (OPVL) spermatozoa number observed in the 1^st egg, which was laid on 3^rd day after last mating was 51.66/mm². Subsequently, the numbers of OPVL-sperm of eggs laid on 4^th, 5^th, 6^th and 7^th day were 45.55, 30.50, 23.00 and 21.75/mm², respectively. Initial number of OPVL-sperm and rate of sperm decline pattern was demonstrated using a simple regression and the relationship was expressed as Y= -8.237 × + 75.67 (R²=0.932). From the equation it was construed that the OPVL-sperm numbers declined at the rate of 7.99/mm² per day and expected to have 2.31 OPVLsperm per mm² on 9^th day in the GD after last mating demonstrated that the fertile period is 9 days in ostrich hens.