EFFECT OF ANTIBIOTIC TREATMENT ON PREGNANCY RATE OF REPEAT BREEDER DAIRY CROSS BRED COWS WITH SUB-CLINICAL UTERINE INFECTION

    The objective of this study was to investigate the effect of antibiotic treatment on pregnancy rate in repeat breeder dairy crossbred cows. Based upon culture and sensitivity test, cows were assigned into two groups. Genta (n = 10) cows were treated with gentamycin (100 mg/ml) and ENRO (n = 12) cows were treated with enrofloxacin (100 mg/ml) intramuscularly 4 ml/100 kg body weight and intra-uterine 2-4 ml diluted with 16 ml of physiological salt solution with 24 hours interval for five days in both groups (five infusions per animal on every other day basis). Control (n = 14) cows were untreated control (non-repeat breeder). After treatment, cows were inseminated approximately 12 h after the standing heat. Pregnancy diagnosis was performed by ultrasonography between days 25 and 30 post insemination. The overall pregnancy rates after three services among three groups were significantly different (P<0.05). The overall pregnancy rates after three services of Genta cows (80%) did not differ significantly (P>0.05) from Control cows (93%). However, overall pregnancy rates of Enro cows (33%) were lower (P<0.05) than Genta and Control cows. In conclusion, the pregnancy rates could be improved by treatment with gentamycin compared to enrofloxacin in repeat breeder dairy crossbred cows with sub-clinical uterine infection.

Key words: Repeat breeder, crossbred cows, antibiotics, pregnancy rate.