Synchronization of Estrus Using EAZI-Breed? CIDR? and FGA-30? Intravaginal Sponge in Pre-Partum Yankasa Ewes

摘要

The efficiency of EAZI-Breed? CIDR? and FGA-30? intravaginal sponges in synchronizing estrus was investigated in prepartum Yankasa Ewes. About 20 randomly cycling pre-partum Yankasa ewes aged between 1.5-2 years and weighing between 13-15 kg was used for this study. They were randomly assigned into two groups, Group A (FGA, n = 10) and Group B (CIDR?, n = 10) for 14 days. Natural mating by a fertile ram was performed following progestagen withdrawal for ewes detected to be on heat. Estrus response in Group A and B was 70 and 80%, respectively. The time to estrus onset following progestagen withdrawal for FGA-30 and CIDR (Mean±SEM) was 43.60±6.98 and 23.57±4.07 h, respectively. In Groups A and B, the duration of induced estrus was (46.65±3.08 and 53.90±5.87 h) while estrus cessation was (90.37±8.44 and 77.92±4.24 h) post withdrawal of the devices. The interval from withdrawal of progestagen to onset of estrus was (p<0.05) longer in FGA than in CIDR (43.60±6.98 vs. 23.57±4.07 h). However, the duration of induced estrus period was shorter in the FGA group than the CIDR group. Retention rate was lower in group A (60%) than B (90%). Drawstring breakage observed in FGA sponges was absent in CIDR devices (20% versus 0) while vaginal discharge rate was higher in group A. These results show that although FGA and CIDR devices are equally efficient in synchronizing estrus in prepartum Yankasa ewes, CIDR provides higher estrus response rate, shorter time to estrus, longer duration of estrus, higher retention rate and ease of application. Consequently, the use of CIDR is recommended.