Affiliation(s)
1. Department of Theriogenology, University of Abuja, Nigeria
2. Artificial Insemination Unit, National Animal Production Research Institute, Shika, Zaria, Kaduna State, Nigeria
3. Department of Theriogenology and Animal Production, Usmanu Danfodiyo University, Sokoto, Nigeria
4. Department of Veterinary Physiology and Biochemistry, University of Abuja, Nigeria
5. Department of Veterinary Parasitology, University of Abuja, Nigeria
ABSTRACT
This study accessed the reproductive performance of Bunaji cows in an Ovsynch
protocol involving ovatide. Bunaji cows (n = 16) aged 4-6 years and weighing
between 250-350 kg with body
condition scores (BCS) of 2.5-3.5 were used. There were
two treatment groups for synchronization of ovulation. Treatment group 1
comprising Bunaji (n = 8) received 50 µg of gonadotropin
releasing hormone (GnRH) (Cystorelin) and 25 mg of PGF2α. While, treatment group 2 comprising Bunaji (n = 8) received 50 µg of ovatide and 25 mg of PGF2α.
All cows from both treatment groups were inseminated at 16 h after each second
GnRH or ovatide injections. Cows that showed
mucus discharge from the vagina on the day of artificial insemination (AI) were
recorded as well as those that had patent cervix. Cervical dilation was
measured by taking note of the cows that had mid cervix insemination due to
non-passage of the AI gun through the cervix. Transrectal palpation was
conducted twice at a month interval to select cycling cows within 5-12 d of the estrous
cycle before initiating Ovsynch protocol. It was repeated on day 45 post AI to
confirm pregnancies in animals. Results showed that the rate of mucus discharge
from the vagina was 37.5% and 87.5% for ovatide and Cystorelin, respectively; while the rate of
cervical dilation were 75% and 87.5% for ovatide and Cystorelin, respectively (p > 0.05), and pregnancy rates were 0% and 12.5% for ovatide and Cystorelin, respectively. There
were no significant differences between the two groups. It was concluded that
treatment of Bunaji cows with 50 µg ovatide in Ovsynh
protocol has heat and ovulation synchronization potentials and zero pregnancy
rate. It was recommended that further studies be carried out using graded doses
of 50, 100 and 150 µg of ovatide in a
fixed time AI synchronization protocol in Bunaji cows, to tap the potentials of
the hormone in manipulation of bovine reproduction.
KEYWORDS
Pregnancy, ovatide, fixed time, AI, synchronization, cows.
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