Effect of Chromium Supplementation on Productive and Reproductive Performances and Some Metabolic Parameters in Late Gestation and Early Lactation of Dairy Cows

The objective of this study was to determine the effect of supplemental chromium as chromium-L-methionine (Cr-Met) on productive and reproductive performances and some metabolic parameters in late gestation and early lactation of dairy cows. Sixty multiparous Holstein dairy cows according to prior lactation, parity, body mass (682?±?33?kg), and expected calving date were divided equally (30 cows/treatment) and were randomly allocated to one of the two groups. One group received basal diet without Cr (control group) and another group received Cr-Met supplement added at manufacturer's recommended level (8?mg of "Cr"/head per day) from 21?days before expected calving date until 21?days of lactation. Supplemental Cr tended to increase milk yield (P?=?0.08) while percentage of lactose and lactose yield increased (P??0.05). Percentage of cyclic cows at 36?days postpartum and estrous behavior before AI was higher in the supplemented group.