SYNCHRONIZATION OF ESTRUS AND FERTILITY IN SHEEP TREATED WITH PROGESTAGEN-IMPREGNATED IMPLANTS, AND PROSTAGLANDINS WITH OR WITHOUT INTRA-VAGINAL SPONGES AND SUBCUTANEOUS PREGNANT MARE SERUM

Synchronisation of oestrus and fertility of 4 groups of 80 ewes were compared. Treatment groups were (1) control, (2) progestagen-impregnated intravaginal sponges, (3) progesterone-impregnated subcutaneous implants, and (4) treated with two injections of prostaglandin 10 days apart. Half of each group re]750i.u. of pregnant mare’s serum (PMS). Synchronisation was precise in Groups2, 3, and 4. The percentage of ewes lambing to first mating in PMS-treated ewes was 71.9, 42.1, 48.6, and 28.9 in Groups 1, 2, 3, and 4 respectively and in ewes not treated with PMS was 83.3, 53.1, 68.4, and 45.7 respectively. Fertility was significantly lower (P < 0.01) in all treated groups than in the control ewes and lower (P < 0.01) in Group 4 than in Group 3 ewes. © 1978 Taylor & Francis Group, LLC.