Effects of prostaglandin administration 10 days apart on reproductive parameters of cyclic dairy nulliparous goats

Abstract

This study reported the effects of prostaglandin (PGF 2 ) administration 10 days apart on reproductive parameters of cyclic artificial inseminated (AI) nulliparous Alpine (n=9) and Saanen (n=9)

Reproductive parameters of dairy goats after receiving two doses of d-cloprostenol at different intervals

“…This confirms results of previous studies in estrus induced goats (Fonseca et al, 2005(Fonseca et al, , 2008. A negative correlation (r = −0.57) between the interval to estrus and the interval to ovulation was reported in estrus synchronized goats with similar T 10 protocol (Fonseca et al, 2012). Thus, considering that AI was performed on average at 24 after estrus onset, T 7 goats were inseminated before the end of estrus and possibly before the ovulation that occurs near the end of estrus (Fonseca et al, 2012).…”

“…Specially in the second cloprostenol administration, this fate can be associated with short estrus cycles. This type of estrus can be more deleterious to a T 10 protocol, as shown earlier (Fonseca et al, 2012), because animals can show estrus before the second PGF2α administration and those goats can have younger CL irresponsive to the effects of exogenous PGF2α administration. In both cases, these goats will not be naturally mated or AI after the second PGF2α administration, decreasing the estrus response in the T 10 protocol.…”

“…On the other hand, previous study showed a negative correlation between the interval to estrus after sponge removal and the respective estrus duration (Fonseca et al, 2008), as shown in the present study. This is supported by the fact that the interval to ovulation was reported as being less variable and also negatively correlated with the duration of estrus (Fonseca et al, 2012) in estrus synchronized goats, a possible indication that goats displaying earlier or later estrus onset after exogenous stimuli were in similar ovarian follicular statuses.…”

“…A negative correlation (r = −0.57) between the interval to estrus and the interval to ovulation was reported in estrus synchronized goats with similar T 10 protocol (Fonseca et al, 2012). Thus, considering that AI was performed on average at 24 after estrus onset, T 7 goats were inseminated before the end of estrus and possibly before the ovulation that occurs near the end of estrus (Fonseca et al, 2012). On average, the other T 10 and T 11.5 goats were inseminated after estrus and ovulation had ended.…”

“…Several studies in our group have recommended the use of two doses of d-cloprostenol (PGF2α) at 10-day intervals (Siqueira et al, 2009;Fonseca et al, 2012;Esteves et al, 2013). However, this protocol does not always achieve the expected success due to the possible occurrence of a short estrus cycle, a reasonably common phenomenon in goats (Camp et al, 1983;Chemineau et al, 2006;Holtz et al, 2008).…”