EFFECTIVENESS OF A SHORT DURATION PROGESTERONE TREATMENT ON SYNCHRONY OF ESTRUS AND FERTILITY IN BARBADOS BLACKBELLY SHEEP

The present study evaluated the effect of a short duration of progesterone treatment prior to injection with prostaglandin F2α on the synchrony of estrus and lambing in sheep. Seventy four (74) Barbados Blackbelly animals, 38 ewes and 36 ewe lambs were randomly assigned to be control animals (C), to receive prostaglandin F2α (i.e. PGF2α, 2 X 10 mg three hours apart, i.m.) on d0 (PG), or to receive 2 injections of progesterone (200 mg, i.m.) on d -4 and on d -2, and PGF2α, on d 0 (PPG). Ewes and ewe lambs were joined with rams on d0 and observations for estrus were conducted until day 5. Lambing data on all ewes were collected and analyzed. The mean proportion of animals lambing was 97% and was not affected by treatment or parity. The mean interval from ram introduction to lambing was (155 ± 6.75 d) and was shorter in PPG-treated animals (i.e.