Effect of Synchronization Protocols on Timing and Duration of Estrus in Nubian Goats

Abstract

Three protocols were conducted to evaluate estrus onset,
duration and synchronization in 18 Nubian goats. The goats were divided
into three groups according to the body weight, 6 animals in each group.
The animals in group one were treated with vaginal sponges (VSP)
impregnated with 45 mg flurogestone acetate (FGA) for 18 days.
Following the removal of the VSP, a single dose of 400 i.u. of pregnant
mare serum gonadotrophin (PMSG) was applied intramuscularly for each
doe. The second group was injected with 7.5 mg/ml prostaglandin (PGF2α)
on day 1 and day12. For the third group, a vasectomized buck was
introduced for 15 days to initiate behavioural estrus after a complete
isolation for four weeks. These experiments were repeated using the same
animals. The results indicated that all protocols (buck effect, PGF2α and
VSP+PMSG) synchronized estrus in Nubian goats with 100% response.
However, the hormonal methods produced more compact synchronization
of estrus than the buck effect. Therefore, the hormonal methods are more
desirable for estrus synchronization, especially in fixed-time artificial
insemination programmes. The mean duration of estrus in the buck effect