title: Short communication: Effects of a monensin premix on milk fatty acid content during subacute ruminal acidosis in dairy cows.
abstract: The effects of a monensin premix on milk fatty acid content during grain-induced subacute ruminal acidosis (SARA) in Holstein cows receiving a total mixed ration was investigated. Six multiparous, rumen-fistulated Holstein cows were used in a two-treatment, two-period crossover design with 6-wk periods. Experimental treatments were either a monensin premix or a placebo premix. At the beginning of wk 4, SARA was induced in experimental cows for a 10-d period using a grain challenge model. The administration of a monensin premix elevated milk fat proportion of total short-chain saturated fatty acids (sum of C4 to C15). Milk fat proportions of conjugated linoleic acid isomers were unaffected. Linolenic acid (C18:3n3) proportion in milk fat of monensin-treated cows were lower when compared with placebo-treated cows during the SARA period. Results from this study indicate that dietary supplementation with monensin during SARA had little effect on milk fatty acid content.
authors.affiliation: Department of Animal and Poultry Science, University of Guelph, Guelph, ON, Canada N1G 2W1.
authors.forename: T
authors.initials: T
authors.lastname: Mutsvangwa
authors.forename: J K G
authors.initials: JK
authors.lastname: Kramer
authors.forename: C B
authors.initials: CB
authors.lastname: Blackadar
authors.forename: T F
authors.initials: TF
authors.lastname: Duffield
authors.forename: R
authors.initials: R
authors.lastname: Bagg
authors.forename: P
authors.initials: P
authors.lastname: Dick
authors.forename: G
authors.initials: G
authors.lastname: Vessie
authors.forename: B W
authors.initials: BW
authors.lastname: McBride
mesh_terms: D000138:Acidosis / Q000517:prevention & control / Q000662:veterinary*; D000704:Analysis of Variance; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000517:prevention & control*; D018592:Cross-Over Studies; D005227:Fatty Acids / Q000032:analysis*; D005260:Female; D007476:Ionophores / Q000009:adverse effects / Q000627:therapeutic use; D019787:Linoleic Acid / Q000032:analysis; D008055:Lipids / Q000032:analysis; D008892:Milk / Q000737:chemistry*; D008985:Monensin / Q000009:adverse effects* / Q000627:therapeutic use; D010919:Placebos; D012417:Rumen; D017962:alpha-Linolenic Acid / Q000032:analysis
chemical_list: D005227:Fatty Acids; D007476:Ionophores; D008055:Lipids; D010919:Placebos; D017962:alpha-Linolenic Acid; D008985:Monensin; D019787:Linoleic Acid