PREVALENCE AND TREATMENT EFFICACY OF REPEAT BREEDING COWS AT NATORE DISTRICT

Abstract

Repeat breeding are those cows that fail to conceive after three or more regularly spaced services in the absence of detectable abnormalities of the internal genitalia. Repeat breeding is one of the main causes of economic loss of dairy farming all over the world including Bangladesh also. The aim of this study was to investigate the effect of treatment repeat breeder dairy crossbred cows with application of GnRH analogue (Ovurelin® ) through IM/route in thoracic region (neck muscle) at two hours before artificial insemination, and determination of pregnancy rates in case of repeat breeder cows. Determination to the prevalence of repeat breeding in cows, the data were collected by using questionnaire from 57 small scale house hold dairy farms and 189 were registered cows among them 40 crossbred dairy cows selected with a definite history of repeat breeding and had a history of 4-6 infertile services but clinically free of diseases were selected as a repeat breeder cow for further study. The animals were divided into two groups. Group A (n=30) cows were treated with GnRH (Gonadotrophin releasing Hormone) 2.5 ml intramuscularly in thoracic region before two hours of artificial insemination. Group B (n = 10) cows were inseminated without intervention any treatment. The treated group (n=30) were further divided into 4 categories where conception percentage 43 in single AI group, 71 percentage in the group of combination with penicillin, 50 percent in the group of double dose of AI and 50 percentage the group performed two times AI at 8 hours interval. The overall conception percentage was observed 54 in treated group and 20 percentages in control group. The results indicated that the pregnancy rate in crossbred cows could be improved by the GnRH treatment. The higher dose of GnRH significantly increased (P < 0.05) the first service as well as overall pregnancy rate in a dose dependent manner in repeat breeder crossbred cow bred previously unsuccessfully. The study was concluded that GnRH is effective in the treatment of repeat breeding cows for achieving conception.