The Effects of Controlled Internal Drug Release for Different Days on the Reproductive Performance of Out of Mating Season Sheep

OpenAlex İngilizce

This study was conducted to determine the effects on reproductive performances of CIDR implants in different periods (days) out of the mating season in a private sheep enterprise. For this purpose, 312 heads ewes of different ages were divided into groups 3 by ages and body conditions. After applying CIDR (include 330 mg of Progesterone), they have been taken on fifth day for group 1, on seventh day for group 2 and twelfth day for group 3 and after removing CIDR; PMSG (400 IU), PGF2? (100 ?g) and GnRH (100 ?g) injected (IM) to all. It has been determined that oestrus rate were found 86.53% for group 1 (5 days), 94.23% for group 2 (7 days) and 82.69% for group 3 (12 days), mating rates were 76.92%, 80.76% and 74.03%, the pregnancy rates were 58.65%, 56.73%, and 47.11%, litter size (prolificacy) by hundred lambed sheep were 146.42%, 128.57% and 136.17%, fecundity were 78.84%, 69.23% and 62.53%. Mortality rate of lambs at birth in group 1, 2 and 3 were found 7.32%, 4.17% and 1.54% respectively. Birth weights of single lambs have been significantly higher than multiple births weights of lambs (p<0.05). It can be concluded that the highest mating rate (p<0.05) has been obtained by the CIDR implementation to the sheep for 7 days, out of the mating season and a quite successful rate is provided when it is compared to external lambing in terms of pregnancy rates.