title: Effect of manganese supplementation on the membrane integrity and the mitochondrial potential of the sperm of grazing Nelore bulls.
abstract: The effect of dietary manganese (Mn(2+)) supplementation on the reproductive performance of Nelore bulls was evaluated by assessment of sperm membrane integrity. Sixty Nelore bulls (Bos taurus indicus) aged 18-20 mo were randomly divided into four groups (n=15) receiving dietary Mn(2+) supplementation at 540, 1300, 3800 and 6300mg/kg (treatments TC, T1300, T3800 and T6300, respectively). The diets were changed for the groups every 70d. Semen samples were obtained 15 and 56d after the diet change, which corresponded to the period of adjustment to the new diet and the time required for a complete spermatogenesis cycle, respectively. Sperm integrity was assessed by detection of: intact (IMe) or damaged (DMe) membranes, intact (IA) or damaged (DA) acrosomes, and high (HM) or low (LM) mitochondrial membrane potentials. Only bulls from the TC treatment showed a significant increase in the production of intact sperm [IMe/IA/LM] and decrease in the production of sperm with damaged acrosome [IMe/DA/LM] or completely damaged sperm [DMe/DA/LM] (P<0.05). The Mn(2+) concentrations in the semen were positively correlated with the incidence of sperm with IMe, DA, and LM and negatively correlated with number of sperm with DMe, IA, and LM. Therefore, dietary Mn(2+) supplementation for Nelore bulls must be limited to 540mg of Mn(2+)/kg given that higher doses are detrimental to the integrity of the plasma and acrosomal sperm membranes.
authors.affiliation: Department of Animal Nutrition and Food Science, University of Santo Amaro, São Paulo, SP, Brazil; Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science, São Paulo State University, Botucatu, SP, Brazil. Electronic address: reis.lsls@gmail.com.
authors.forename: L S L S
authors.initials: LS
authors.lastname: Reis
authors.affiliation: Department of Animal Production, School of Veterinary Medicine and Animal Science, São Paulo State University, Botucatu, SP, Brazil.
authors.forename: A A
authors.initials: AA
authors.lastname: Ramos
authors.affiliation: Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science, São Paulo State University, Botucatu, SP, Brazil.
authors.forename: A S
authors.initials: AS
authors.lastname: Camargos
authors.affiliation: Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science, São Paulo State University, Botucatu, SP, Brazil.
authors.forename: E
authors.initials: E
authors.lastname: Oba
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D008297:Male; D008345:Manganese / Q000008:administration & dosage / Q000494:pharmacology*; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects*; D051336:Mitochondrial Membranes / Q000187:drug effects*; D012621:Seasons; D013094:Spermatozoa / Q000187:drug effects* / Q000502:physiology
chemical_list: D008345:Manganese
keywords: Cattle; Integrity of sperm membrane and acrosome; Manganese; Mineral salt; Spermatozoa