Stimulation of Estrus and Ovulation by Resynchronization in Kangal Sheep during Early Anestrus
Abstract
Abstract: A total of 100 Kangal sheep were divided into four groups with the aim of investigating
the effectiveness of resynchronization during anestrus for the first time in the literature. The groups
were then divided into two further subgroups, namely the resynchronization subgroup group
(hCG+resynch) and group (resynch)) and the no resynchronization subgroup (Group (hCG) and
group (control)). All the groups started with progesterone-containing sponge insertion on Day
7. The sponge was removed after 7 days (on Day 0), and 600 IU eCG + 131.5 µg PGF2α was
injected. The animals in group (hCG+resynch) and group (hCG) received hCG injection at the time of
sponge administration. Accordingly, four different groups were established, i.e., resynchronization
+ hCG administration group (hCG+resynch); n:25), no resynchronization + hCG administration
(group (hCG); n:25), resynchronization + no hCG administration (group (resynch); n:25), and no
resynchronization + no hCG administration (Group (control); n:25). Estrus rates at the first application
in group (hCG+resynch), group (hCG), group (resynch), and group (control) groups were 76%, 88%,
96%, and 76%, respectively, and pregnancy rates were 52%, 64%, 72%, and 60%, respectively; there
were no intergroup statistical differences in the two parameters above. It was concluded that
resynchronization performed with two consecutive stimulations during anestrus could help save
time and provide a pregnancy rate at a level that can provide economic returns.