SHORT-TIME PROTOCOL WITH FLUROGESTONE ACETATE TO OESTRUS SYNCRONIZATION IN CHAMOIS COLOURED GOATS

Intravaginal sponges impregnated of progestins are classically used to synchronize oestrus in small ruminants. Considering the 21-day oestrus cycle of the goat, first protocols scheduled long-time (17-21 days) permanence of the sponges. A shorter and more efficient 11-day protocol was proposed combining progesterone treatment with a single PGF2α dose administration on day 9 or 11 in order to remove an eventual corpus luteum and promote ovulation. Considering follicular dynamics, 5-7-day protocols have been tested in goats with various devices. Aim of this study was the comparison of a short lasting protocol (6 days) and a medium lasting protocol (11 days) for the oestrus synchronization of goats. After ethical approval by the Department of Messina (reference number 014/17), 50 Chamois Coloured goats from a farm of Cosenza, Italy (39 degrees N, 16 degrees E, altitude 926 m) were enrolled in the study and randomly assigned to group A and B. The criteria of selection were: age (2-5 years), parity (≥1), days open (more than 5 months from the last kidding), body condition score (from 2.5 to 3.0), health status (lack of evidence of mastitis, abscesses, lameness, ultrasound abnormality of the internal reproductive tract). This study was performed in September (breeding season). In group A (25 goats), the sponge containing 20 mg flurogestone acetate was inserted on day 0 and removed on day 6; 0.05 mg of cloprostenol (Estrumate, MSD Animal Health) and 400 UI of equine chorionic gonadotropin (Folligon, MSD Animal Health) were given on day 6. After 36 hours (day 8), 3 bucks (ratio 1:8) with good libido and of proven fertility were introduced in the group until day 11. In group B, the same sponges were maintained for 11 days whereas cloprostenol and equine chorionic gonadotropin were administered on day 9. Thirty days after the removal of bucks, the goats were evaluated by ultrasound for pregnancy diagnosis. All the data were analysed with Fisher-Yates test, and statistical significance was set at 0.05. Only one sponge (4%, p>0.05) was lost in group B and the goat was excluded from the study. At the removal of the sponge, vaginal contamination (fluid and odour) was observed in 10 and 90% of the goats in group A and B (p<0.01), respectively. Oestrus and mating was registered in 96 and 100% (p>0.05) of goats while pregnancy rate was 79 and 76% (p>0.05), in group A and B. No pseudopregnancy was detected. In conclusion, both protocols worked well under the study conditions, allowing a massive synchronization of fertile oestruses from 36 to 72 hours after the sponge removal. The short lasting protocol may give some benefits: easier scheduling, less visits by vets and less costs for the farmer, less hormones in the farm and less residues in the milk, lower exposition time to intravaginal sponges with lower grade of vaginal contamination and improved animal welfare.