RELATIONSHIP OF ELECTRICAL RESISTANCE OF VAGINAL MUCUS DURING OESTRUS WITH POST-AI PREGNANCY IN COWS

摘要

Accurate detection of oestrus is a common problem for farmers to do AI timely resulting in conception failure in cows. The objective of the present study was to know the electrical resistance of vaginal mucus (ERVM) during oestrus to determine the best time of AI for improvement of conception in cattle. A total of 28 cows were inseminated with frozen thawed semen after detection of ERVM with Draminski estrus detector at Kendua Upazila Livestock Office under Netrakona district of Bangladesh. Pregnancy was diagnosed by per rectal palpation of genital tract 8-10 weeks after insemination. The mean ERVM in pregnant cows was 208.5 ± 31.2 Ω (163.3 to 263.3 Ω) and the ERVM in non-pregnant cows was 214.4 ± 36.6 Ω (153.3 to 280.0 Ω). Moreover, the pregnancy rate was higher in cows (80.0 to 83.3%) when ERVM during oestrus varied from 150 to 220 Ω than that of 221 to 280 Ω counterpart (36.4%). The difference in pregnancy rates between groups was significant (P&0.05). The present study indicates that Dramniski electrical heat detector may be used for prediction of time for AI in cows of Bangladesh. Up to 220 Ω ERVM during oestrus is better for higher conception rate than that of more than 220 Ω counterparts. Further studies with high number of inseminated cows should be conducted before wide application of this electrical heat detector under field conditions in Bangladesh.