Estrus response and pregnancy rate of Rusa timorensis following estrus synchronization with prostaglandin analogue

Abstract

The purpose of this study was to evaluate the efficacy of cloprostenol in inducing estrus in cycling Rusa timorensis hinds by assessing circulating progesterone (P4) concentration, occurence of estrus and pregnancy rate. Estrus was synchronized in eight cycling hinds with 500 ?g cloprostenol given intramuscularly at 10 days apart. Eight other R. timorensis hinds were not-synchronized and served as control. Blood samples, collected every three to four days for 29 days from 24 hours prior to the first cloprostenol injection, were analyzed for plasma progesterone concentration. Estrus was recorded based on observation of estrus signs during the period of blood sampling and all hinds were subjected to transrectal ultrasonography to assess pregnancy status. On the basis of changes in plasma progesterone concentration, cloprostenol induced estrus in only 63% of the treated hinds. The other three treated hinds showed progesterone values (0.8 ng/mL) which appeared to be too low to indicate presence of corpus luteum for the drug to act on. Spontaneous estrus occurred in 50% of the untreated hinds. Five of the 8 treated hinds and four control hinds displayed standing estrus. Pregnancy rate to cloprostenol induced estrus following natural mating was good with 50% of the treated hinds conceived. In the present study, estrus synchronization had been successfully achieved using prostaglandin analogue.

Keywords

• Rusa timorensis
• estrus synchronization
• cloprostenol
• pregnancy rate