Abstract

An investigation was done to observe follicle development and ovulation by ultrasound in a synchronization protocol in Bunaji cows using ovatide. Cows (n=16), aged 4 to 6 years with average body condition scores of 2.5 to 3.5 and weighing between 250 and 350 kg were used. They were managed according to the routine management practice of the Diary Research Programme NAPRI. Only cycling cows at 75 days post-partum with palpable CL were included in the study. Cows were randomly assigned to 1 or 2 treatment groups for synchronization of ovulation. Treatment group 1 comprising Bunaji (n=8) received 50 µg of GnRH and 25 mg of PGF_2α. While, treatment group 2 comprising Bunaji (n=8) received 50 µg of ovatide and 25 mg of PGF_2α. The treatment was as follows: Group 1: (Day 0, 50 µg GnRH; Day 7, 25 mg PGF_2α and day 9, 50 µg GnRH), group 2: (Day 0, 50 µg ovatide, Day 7, 25 mg PGF_2α and Day 9, 50 µg ovatide). Ultrasound examinations were conducted. Examinations were conducted at the time of second gonadotropin injections, to determine presence of one or more antral follicles > 10 mm in diameter and at 48h after second gonadotropin injections, to determine absence of 1 (single – ovulation) or 2 (double – ovulation) of those earlier antral follicles. Results showed synchronization rate for ovatide was 75%, while that of GnRH (Cystorellin) was 62.5% (p>0.05). Double ovulation rate for both groups was 0%. It was concluded that 50 µg Ovatide in Ovsynh protocol has synchronization potentials in Bunaji cows.  Further studies on gonadotropins of fish origin are recommended.

Key words: Ovatide, follicle, sonographic, synchronization, Bunaji, cows.