Proceedings of the 5th International Symposium on EQUINE ...

Equine Embryo TransferTABLE 1: Success rates <strong>of</strong> induction <strong>of</strong> ovulation in Experiments 1 and 3Exp 1 (72 paired oestrous cycles) Exp 3 (60 paired oestrous cycles)Busereline Placebo P Busereline Busereline P40 µg x4 40 µg x4 20 µg x4Ovulation within 48 hafter 1st injection 61% 22% < 0.00 183% 90% N.S.Ovulation between 24and 48 h after1st injection 47% 14% < 0.054 7% 57% N.S.TABLE 2: success rates <strong>of</strong> induction <strong>of</strong> ovulation in Experiment 4 and 5Exp 4 (50 paired oestrous cycles) Exp 5 (60 paired oestrous cycles)Busereline hCG P Busereline hCG P20 µg x 4 2500 ui 13.3 µg x 3 2500 uiOvulation between32 and 48 hafter 1st injection 56 % 76 % N.S. 57 % 50 % N.S.Mean time <strong>of</strong>ovulation ± sd 39.5 ± 3.1 h38.4 ± 2.5 h N.S .43.1 ± 2.1 h 37.7 ± 2.3 h < 0.01<strong>of</strong> ovulation did not differ significantly between<strong>the</strong> 2 treatments (busereline 3 x 13.3 µg or hCG2,500 ui). However, <strong>the</strong>re were many earlyspontaneous ovulations within 32 h after <strong>the</strong> start<strong>of</strong> treatment quite only in cycles treated with hCG(11/30 versus 1/30). When ovulation occurredbetween 32 and 48 h after <strong>the</strong> first or <strong>the</strong> onlyinjection, <strong>the</strong>re was a significant difference(P