A. Malik, A. Wahid, Y. Rosnina, M. Bukar, Yimer , A. Kasim, M. Sabri,
Effects of Resynchronization with Progesterone and Prostaglandin F2• on Estrus Response and Pregnancy Rate in Beef Cattle,
Journal of Animal and Veterinary Advances,
Volume 10,Issue 18,
2011,
Pages 2474-2478,
ISSN 1680-5593,
javaa.2011.2474.2478,
(https://makhillpublications.co/view-article.php?doi=javaa.2011.2474.2478)
Abstract: This experiment was designed to compare the estrus response
and pregnancy rate of cows first synchronized using CIDR with cows that were
resynchronized after failing to display estrus. Estrus response and pregnancy
rate were also compared between cows resynchronized with either CIDR or prostaglandin
F2• (PGF2•). Initially, 140 Brangus cows were
synchronized with CIDR. About 30 days after Artificial Insemination (AI), cows
were checked for pregnancy using ultrasound and those that remain open were
divided into two groups and resynchronized with either CIDR or two injections
of PGF2• at 11 days interval. All cows were observed visually
for estrus response for a period of 2 h at 12 h interval, starting immediately
after CIDR removal or after the second injection of PGF2•.
Cows were in estrus when they mounted if at least 3 times during the period
of observation. Following removal of CIDR and second injection of PGF2•,
cows were inseminated 60 and 70 h later, respectively. There were no significant
differences (p>0.05) in estrus response and pregnancy rate between cows initial
synchronization and resynchronization with CIDR protocol. Although, statistically
not significant there was relatively higher percentage of estrus response (81.6
vs. 70%) and pregnancy rate (30.6 vs. 28.0%) in cows resynchronized with CIDR
than cows resynchronized with PGF2•.
Keywords: estrus response;PGF2•;CIDR;resynchronization;Beef cattle;pregnancy rate