Estrus responses, transcervical artificial insemination and rectal digital palpation in crossbred boer goats

A series of experiments were conducted with crossbred Boer goats to study the signs of estrus responses, transcervical artificial insemination and rectal digital palpation. In experiment I, 33 does (group C) were synchronized with CIDR for 18 days and 37 does (group Ce) were synchronized with CIDR for 18 days followed by injection with 250 I.U of eCG after withdrawal of CIDR device and the sign of estrus, follicular growth and onset and duration of estrus were recorded. In experiment II, 25 does from group C, were divided into two subgroups, C1 for transcervical AI (12 does) and C2 for natural mating (13 does) and 25 does from group Ce were divided into two subgroups, Ce1 for transcervical AI (12 does) and Ce2 for natural mating (13 does). For trancervical AI, does from subgroups (C1 and Ce1) were inseminated with transcervical frozen-thawed semen, 47 to 51 hours after removal of CIDR device. In the natural mating subgroups (C2 and Ce2), all does were naturally mated with the bucks after exhibiting estrus in does. For pregnancy diagnosis, all does were cheeked by ultrasonography on day 40 post breeding. In experiment III, 47 does were synchronized with a Short-Term Protocol. The does were naturally mated with 1:16 buck and does ratio. The bucks were introduced in the herd for breeding, one day after removal of CIDR device. Rectal digital palpation (RDP) and ultrasonography for pregnancy diagnosis were conducted at days 40, 50 and 60 post-breeding. Ultrasonography was used as gold standard to compare the RDP in pregnancy diagnosis. In RDP technique performance was determined by sensitivity and specificity. In experiment I, does in both group (C and Ce) after treatment showed 100% signs of estrus. No significant differences (p> 0.05) of estrus behaviour such as mounting, tail wagging, vulva swelling and increased vaginal temperature were observed in both treatments. However, for clear mucous discharge from the vulva during estrus, group Ce was significantly higher than group C (p < 0.05). Data of mean number of follicle showed that does given CIDR + eCG was significantly higher than does given CIDR (P<0.05). No significant difference (P>0.05) of the onset and duration of estrus between CIDR and CIDR+eCG treated does. In experiment II there was a significant difference (P<0.05) in the fertility rate of natural breeding and transcervical AI. However, there was no significant difference (P>0.05) in fertility rate between estrus synchronization using CIDR and CIDR + eCG on natural mating and transcervical AI. In experiment III sensitivity of RDP at 40, 50 and 60 days after gestation were 80.95%, 33.33% and 33.33% respectively and specificity were 73.08%, 77.27% and 90.91% respectively. The results indicate that estrus in crossbred Boer goat can be efficiently synchronized by using CIDR treatment and estrus synchronization with CIDR + eCG produce more discharging of clear mucus streaks from vulva during estrus period. In addition, the present study shows that transcervical AI using frozen thawed semen of Boer goat, inseminated 47 to 51 hours after removal of CIDR device can lead to good conception rate and RDP can be used for diagnosis of early pregnancy due to its high sensitivity at 40 days of gestatio