SK Bhowmik
Department of Surgery and Obstetrics, Faculty of Veterinary Science, Bangladesh
Agricultural University, Mymensingh-2202, Bangladesh.
MGS Alam
Department of Surgery and Obstetrics, Faculty of Veterinary Science, Bangladesh
Agricultural University, Mymensingh-2202, Bangladesh.
M Shamsuddin
Technical Officer
Animal Production and Health Section, IAEA/FAO, Vienna, Austria.
M Khatun
Endeavour PhD Fellow
Dairy Research Group, C04, MC Franklin Laboratory, Faculty of Veterinary Science, University of Sydney, Australia I 2570
Fertility, Cow, Potential
Mymensingh and Netrakona district.
Variety and Species
A total of 35 local zebu cows and their crosses belonged to private farms were included. Twenty five cows were from Sutiakhali of Mymensingh district, 10 were from Satpai of Netrakona district, 27 were crossbred between local indigenous with Holstein-Friesian, Sindhi or Sahiwal and eight were local indigenous. Age of the animals was determined from register or by dental examination. The body weight of animals was estimated by using a standardized tape. The body condition score (BCS) of the cows was scored (1 – 5 scale) following modification of the method. Cows that did not show oestrus by three months postpartum were selected. The cows were examined per rectum to confirm that they were not pregnant. The cows with puerperal complications were not included. Age, body weight, BCS, parity, postpartum intervals of cows varied from 4 – 15 years, 125 – 375 kg, 1.5 – 3.0, 1 – 9, 4 – 12 months, respectively.
The cows were housed in tied standings with limited floor space and good ventilation. Most of the houses were made of wood, bamboo, tin and straw: some were made of concrete. Some of the cows were turned out for grazing for six hours daily. Approximately 5 – 6 kg roughages and 1.5 – 2 kg concentrates were given daily to each animal with ad libitum water. The concentrate feed consisted of rice polish, wheat bran, oil cakes, molasses and salt. Lactating cows were milked by hand twice daily at an interval of 8-9 hours with their calves. All cows were clinically examined and cows found in normal health were included. The treatment schedules are presented. Each animal was given two single intramuscular injections of 2 ml Prosolvin® 10 days apart regardless of the stage of the oestrous cycle. Oestrus was detected twice da ily at an interval of 12 hours for 5 days after each PGF 2 -α injection. Induced oestrus was detected on the basis of standing to be mounted, redness and swelling of the vulva and genital discharge. After synchronization, the cows were divided into three groups.
Group-I: Eleven cows were inseminated without further treatment. Group-II: Twelve cows were injected i.m. with GnRH analogue (single dose of 2.5 mL Fertagyl®, Gonadorelin; 0.1 mg/mL, Intervet International B. V. Boxmeer, Holland) just prior to insemination. Group-III: Three days after second injection of PGF 2 -α analogue, 12 cows with smooth ovaries were injected with 2.5 mL Fertagyl®. Nine days later the cows received 2 mL Prosolvin® and cows were observed for oestrus at 12-hour intervals for 5 days.
The cows were inseminated 12 hours after the onset of oestrus or, when oestrus signs were not evident, fixed-time insemination was done at 72 and 96 hours. Twenty-five cows were inseminated with liquid semen from the University AI Center, Mymensingh, diluted with egg yolk citrate as described and used within 24 hours of processing. Ten cows of Netrakona district were inseminated with frozen semen in 0.25 mL French straws (Central Cattle Breeding Station, Savar, Dhaka). In both cases, the inseminations were performed by trained AI technicians. Cows were examined for pregnancy by rectal palpation between 60-90 days after insemination as described. Chi-square (χ2 ) test was used to estimate the difference between observed oestrus AI and fixed time AI and between different groups with respect to the proportion of pregnant animals.
Bangl. vet. 2014. Vol. 31, No. 2, 60-69, ISSN 1012-5949
Journal