This experiment was conducted to study the effects of supplemental chromium on the reproductive performance of dairy cows. Thus, twenty multiparous Holstein cows (parity 3) were allocated to two treatments groups with ten replicates in a completely randomized design. In this study, the treatment consists of control group which received no chromium supplementation and treatment group which received 5 g/day of chromium from chromium methionine. The cows used for this experiment were within the range of 5 weeks prior to parturition to 12 weeks after parturition. Reproduction parameters consisting of insemination index and numbers of open days, clinical metabolic disorders which included acidosis, milk fever, retained placenta and displaced abomasums, and also clinical puerperal complications consisting of mastitis, endometritis and ovarian cysts, were determined. The results indicated that chromium (Cr) supplementation significantly caused a decrease in the numbers of open days (p < 0.05). Clinical metabolic disorders and clinical puerperal complications were not affected by chromium methionine supplementation. The results of this experiment also showed that chromium methionine supplementation in multiparous dairy cows diet may improve their milk yield and reproductive performance in transition period.

Key words: Dairy cow, transition period, chromium methionine, reproduction.