Received: 06-07-2018 / Accepted: 08-09-2018
The study was performed to evulate the efficacy of “made-in Vietnam” progesterone releasing device in regulating the reproductive cycle of dairy herd in Bavi district, Hanoi, from February 2017 to November 2017. That applying of Ovsynch plus intravaginal device (ProB in the experimental group; CIDR® in the control group) resulted in high rate of estrus expression in both groups; especially during the period of 2-3 days post-treatment. In addition, the estrus rate according to BCS and parity of the cows was also assessed, which revealed that the cows with lower parity were more active with the protocol than those with higher parity (above 3th parity). It is also noted that the distribution of oestrus cows mainly concentrated on the BCS ranging from 2.75 to 3.0. With the feasible results of determinating the vaginal irritation as an effect of the devices, the authors tentatively recommended introducing ProB to dairy cows across the country.