EFFECT OF TREATMENT WITH CIDR ON CONCEPTION RATE OF POST INSEMINATED REPEAT BREEDER HIGH YIELDING DAIRY COWS

The objective of this study was to evaluate the effect of post insemination supplementation with CIDR for 7 days on conception rate in repeat breeder high yielding dairy cows.
High yielding cows (n=60) (Peak>45kg) were divided randomly into treatment and control groups while all were repeat breeders (minimum 4 unsuccessful insemination). Treated cows (n=30) received a CIDR on day 5 post insemination which was removed after a week. Control cows (n=30) did not receive any treatment.
Considered parameters were pregnancy rate in first service and the average number of service to pregnancy following the applications of CIDR.
Pregnancy rate in first service following the applications of CIDR was not significantly different between treatment group (46.7%) and control group (26.7%) (P=0.11).
The average number of service to pregnancy following the applications of CIDR into treatment group (1.06±1.31) was not significantly different compared to that for the control group (1.16±0.98) (P=0.10).
Results indicated that supplementation with CIDR from 5 to 12 days post-insemination does not improve conception rate in repeat breeder high yielding dairy cows (P>0.05).