A preliminary study on the effect of intrauterine infusion of neem oil on innate immunity, endometrial inflammatory cytokines, recovery, and conception rate in repeat breeder dairy cows

The present study evaluated the immuno-modulatory effect of intrauterine infusion of Neem oil (twice at 24 h interval) in repeat breeding cows (n=6) suffering with sub-clinical endometritis and compared with untreated control (n=6). There were no changes in the mean blood leucocyte count, lymphocytes (%), neutrophils (%) and monocyte (%) between and within groups. The phagocytic activity of blood neutrophils and monocyte was increased at next estrus compared to that at 0 h and 24 h of treatment in treated cows (NO), while, it did not differ in untreated control. The mean stimulation index (lymphocyte proliferation) was significantly higher at next estrus in NO treated cows compared to untreated control. The endometrial mRNA expression of IL-6 (0.18 fold), IL-1α (0.25 fold) and TNF- α (0.38 fold) were downregulated after the treatment in treated cows, while the mRNA transcript of IL-10 (3.28 fold) was upregulated after the treatment in group NO compared to control. All the cows showed negative endometrial cytology for PMNs after the treatment in NO group. The cervical mucus bacterial load reduced significantly at next estrus in treated cows compared to untreated control as well as after the treatment compared to before the treatment. The first service conception rate was 50% (3/6) in treated cows, while, the corresponding figure in untreated control was 16.67% (1/6). In conclusion, methanolic extract of neem oil may improve the recovery and conception rate in cows with sub-clinical endometritis through its bactericidal and immunomodulatory activity.