Anjum I.A., Usmani R.H., Tunio M.T. Abro S.H.
Abstract
The study was carried out to evaluate the effect of Dalmarelin (Lecirelin acetate, GnRH analogue) administration at
the time of AI on conception rate in repeat breeding crossbred cattle. A total of 64 cows maintained at the Government
Farm Okara were included in the study. Age of these cows ranged from 44 to 232 months and their lactation number
varied from 1-13. The experimental cows were divided into control and treatment groups. The average age and lactation
number of cows of the control and treatment groups did not differ. In this experiment 32 cows received no treatment
at the time of AI while in other group 32 cows received Dalmarelin (GnRH analogue) therapy at the time of AI. The
cows were examined after 60 days post insemination per rectum. A total 12 animals out of 32 confirmed pregnant after
examination having conception rate 37.5% in control group and in treatment group 22 animals out of 32 confirmed
pregnant after rectal examination having conception rate 68.75% (P < 0.0242/x2: 5.082). The data regarding postpartum
interval, estrus duration and estrus behaviour was collected and analyzed, which was non-significant. The study
revealed that use of GnRH analogue therapy improved the conception rate in repeat breeding crossbred cows when it was
administered at the time of AI.
Key words:
conception rate, repeat breeding, crossbreed cows, GnRH analogy therapy