title: Effect of chromium supplementation on productive and reproductive performances and some metabolic parameters in late gestation and early lactation of dairy cows.
abstract: 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<0.01). Chromium supplementation decreased serum nonesterified fatty acids concentration at 7 days prepartum and 21 days postpartum. Serum insulin concentration for cows receiving Cr was higher than the control group (P=0.05). Serum cortisol concentration decreased (P<0.05) in prepartum period in supplemented group. Chromium did not affect concentrations of metabolic parameters at calving. However, serum glucose concentration increased at 21 days postpartum in the supplemented group (P<0.05). Chromium supplementation increased neutrophil and neutrophil to lymphocyte ratio in prepartum period (P<0.05). Based on serum concentrations of progesterone, days to first ovulation tended (P=0.07) to occur earlier in the supplemented group. Furthermore, days to first service and days to first estrus of the supplemented group occurred earlier than the control group (P<0.05) but days open, services per conception and conception rates at first insemination did not differ between two groups (P>0.05). Percentage of cyclic cows at 36 days postpartum and estrous behavior before AI was higher in the supplemented group.
authors.affiliation: Department of Animal Science, Faculty of Agriculture, Razi University, Kermanshah 6719685416, Iran. kafilzadeh@razi.ac.ir
authors.forename: F
authors.initials: F
authors.lastname: Kafilzadeh
authors.forename: H Karami
authors.initials: HK
authors.lastname: shabankareh
authors.forename: M R
authors.initials: MR
authors.lastname: Targhibi
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001786:Blood Glucose; D001835:Body Weight / Q000187:drug effects; D002417:Cattle / Q000378:metabolism*; D002857:Chromium / Q000008:administration & dosage / Q000494:pharmacology*; D019587:Dietary Supplements; D004971:Estrus / Q000187:drug effects / Q000378:metabolism; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D006854:Hydrocortisone / Q000097:blood; D007328:Insulin / Q000097:blood; D007774:Lactation / Q000187:drug effects / Q000378:metabolism*; D008214:Lymphocytes / Q000378:metabolism; D008715:Methionine / Q000008:administration & dosage / Q000494:pharmacology; D008892:Milk / Q000378:metabolism; D009504:Neutrophils / Q000378:metabolism; D049590:Postpartum Period / Q000187:drug effects; D011247:Pregnancy / Q000187:drug effects* / Q000378:metabolism; D011374:Progesterone / Q000097:blood; D012098:Reproduction / Q000187:drug effects*
chemical_list: D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D002857:Chromium; D011374:Progesterone; D008715:Methionine; D006854:Hydrocortisone