Determination of the efficacy of human Chorionic Gonadotropin (hCG) administrations on reproductive performance, placentation, parturition, and neonatal parameters on different post–mating days in Kangal ewes sexually induced during anestrus
Özet
This study aimed to determine the efficacy of post mating human
Chorionic Gonadotropin (hCG) during anestrus on the formation of
the accessory corpus luteum and some reproductive parameters. For
this purpose. after synchronization of all the animal were divided into
group 1 (n=100), group 2 (n=100), and group 3 (n=100) by applying 600
IU of hCG 6 d after sponge removal, 600 IU of hCG 8 d after sponge
removal, and no hCG application (Control), respectively. The difference
between groups in terms of reproductive parameters such as estrus,
pregnancy, multiple pregnancy, litter size, and productivity was not
statistically significant. The live birth weight of lambs was evaluated
for singletons, twins, and triplets. The difference between group 1
and the control group was statistically significant in singleton lambs
(P=0.04). The difference between group 1 and control (P<0.001) and
between group 2 and control (P<0.001) was statistically significant for
twins. In triplets, group 1 was different from both groups (P<0.001) and
group 2 was different from the control group (P<0.001). In addition,
when the placenta weight and the daily body weight gain of singleton
lamb in the neonatal stage were examined, the values of both groups
that were administered with post mating hCG were higher than the
control group (P<0.001). The Progesterone (P4) level in blood samples
taken on the 21st d of pregnancy was found to be different between
all groups. Furthermore, P4 levels were found to be higher in group
1 compared to the other two groups (P<0.001). In the light of these
findings, it was determined that hCG administration after mating
contributed to placenta and offspring development by elevating P4
levels. It was concluded that hCG should be administered 6 d after
the sponge will be removed (on d 5 postmating) for optimal efficacy