title: Effect of dietary organic zinc, manganese, copper, and cobalt supplementation on milk production, follicular growth, embryo quality, and tissue mineral concentrations in dairy cows.
abstract: This study evaluated potential effects of organic trace mineral supplementation on reproductive measures in lactating dairy cows. Cows were blocked by breed and randomly assigned at dry-off to receive inorganic trace mineral supplementation (control; n = 32) or to have a portion of supplemental inorganic Zn, Cu, Mn, and Co replaced with an equivalent amount of the organic forms of these minerals (treatment; n = 31). Trace minerals were provided through control or treatment premixes fed at 100 g·cow(-1)·d(-1). Premixes were fed to dry cows (range = 40 to 72 d before calving) in 1.8 kg·cow(-1)·d(-1) concentrate pellets through a computer feeder to provide 40, 26, 70, and 100% of supplemented Zn, Mn, Cu, and Co, respectively, and to lactating cows (range = 69 to 116 d after calving) in a total mixed ration to provide 22, 14, 40, and 100% of supplemented Zn, Mn, Cu, and Co, respectively. Treatment increased milk production at wk 14 (P = 0.047) postcalving, milk urea N content (P = 0.039), and BW loss from calving to 1 mo postcalving (P = 0.040), and decreased milk fat percentage (P = 0.045) and BCS (P = 0.048). Treatment tended to increase milk production at wk 13 (P = 0.089) postcalving and endometrial tissue concentrations of Fe (P = 0.070), BW at mo 1 (P = 0.056), and milk protein percentage (P = 0.064). Treatment did not affect (P > 0.1) DMI, health events, first-wave follicular dynamics, first cycle luteal measures, embryo quality, liver trace mineral concentrations, or luteal trace mineral concentrations. Cows with a rectal temperature ≥39°C at the time of AI had a smaller percentage of fertilized entities (P < 0.001). However, of the entities that were fertilized, the percentage of viable embryos, embryo quality, accessory sperm number, and embryo cell number were not affected (P > 0.1) by treatment. We conclude that replacing a portion of inorganic supplemental trace minerals with an equivalent amount of these organic trace minerals (Zn, Mn, Cu, and Co) increased milk production in mid-lactation, but did not affect postpartum follicular dynamics, embryo quality, or liver and luteal trace mineral concentrations.
authors.affiliation: Department of Dairy Science, University of Wisconsin, Madison 53706, USA.
authors.forename: K S
authors.initials: KS
authors.lastname: Hackbart
authors.forename: R M
authors.initials: RM
authors.lastname: Ferreira
authors.forename: A A
authors.initials: AA
authors.lastname: Dietsche
authors.forename: M T
authors.initials: MT
authors.lastname: Socha
authors.forename: R D
authors.initials: RD
authors.lastname: Shaver
authors.forename: M C
authors.initials: MC
authors.lastname: Wiltbank
authors.forename: P M
authors.initials: PM
authors.lastname: Fricke
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle / Q000502:physiology*; D003035:Cobalt / Q000008:administration & dosage / Q000494:pharmacology; D003300:Copper / Q000008:administration & dosage / Q000494:pharmacology; D003612:Dairying; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D004622:Embryo, Mammalian / Q000187:drug effects*; D004973:Estrus Synchronization; D005260:Female; D007774:Lactation / Q000187:drug effects*; D008345:Manganese / Q000008:administration & dosage / Q000494:pharmacology; D008670:Metals / Q000008:administration & dosage* / Q000494:pharmacology; D008892:Milk; D008903:Minerals / Q000032:analysis*; D006080:Ovarian Follicle / Q000187:drug effects*; D049590:Postpartum Period; D015032:Zinc / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D008670:Metals; D008903:Minerals; D003035:Cobalt; D008345:Manganese; D003300:Copper; D015032:Zinc