title: Inclusion of flaxseed in hay- and barley silage diets increases alpha-linolenic acid in cow plasma independent of forage type.
abstract: Feeding flaxseed to cattle may be a means of increasing omega-3 fatty acid levels in ruminant products, but possible interactions with conserved forages have not been investigated. Twelve Holstein cows were used in a replicated 4 × 4 Latin Square experiment. Cows were fed one of four 50:50 forage:concentrate diets (DM basis): hay (hay control, HC), hay plus 15% ground flaxseed (hay-flaxseed, HF), barley silage (silage control, SC), and barley silage plus 15% ground flaxseed (silage-flaxseed, SF). Plasma concentrations of alpha-linolenic acid (ALA) did not differ between SC and HC diets. Flaxseed increased ALA (P < 0.05), but levels were not influenced by forage type. Flaxseed slightly increased 18:2n-6 (P < 0.05) and some n-6 and n-3 elongation and desaturation products, particularly arachidonic acid (ARA) and eicosapentaenoic acid (EPA). Flaxseed also increased C18:0 (P < 0.05) with this increase being greater (P < 0.01) for cows fed SF than HF. Feeding flaxseed also increased plasma C18:1-trans isomers (P < 0.01), predominantly vaccenic acid (VAA, 18:1-t11), with this increase being greater (P < 0.05) in cows fed HF than SF. Although conjugated linoleic acid (CLA) was increased (P < 0.001) with flaxseed it was not influenced by forage type (P = 0.06). Overall, feeding flaxseed increased plasma ALA, EPA, ARA and CLA independently of forage type. Feeding flaxseed with silage, however, resulted in more 18:0, while feeding flaxseed with hay resulted in greater accumulations of plasma 18:1-trans isomers mainly in the form of VAA.
authors.affiliation: Agriculture and Agri-Food Canada, Research Centre, Lethbridge, AB, Canada.
authors.forename: M L
authors.initials: ML
authors.lastname: He
authors.forename: Y-H
authors.initials: YH
authors.lastname: Chung
authors.forename: T A
authors.initials: TA
authors.lastname: McAllister
authors.forename: K A
authors.initials: KA
authors.lastname: Beauchemin
authors.forename: P S
authors.initials: PS
authors.lastname: Mir
authors.forename: J L
authors.initials: JL
authors.lastname: Aalhus
authors.forename: M E R
authors.initials: ME
authors.lastname: Dugan
mesh_terms: D000824:Animal Nutritional Physiological Phenomena / Q000502:physiology*; D000818:Animals; D016718:Arachidonic Acid / Q000032:analysis / Q000097:blood; D002417:Cattle; D004032:Diet / Q000662:veterinary; D015118:Eicosapentaenoic Acid / Q000097:blood; D005227:Fatty Acids / Q000032:analysis* / Q000097:blood*; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage; D005260:Female; D019597:Flax; D001467:Hordeum; D044243:Linoleic Acids, Conjugated / Q000097:blood; D009829:Oleic Acids / Q000097:blood; D010949:Plasma; D012820:Silage / Q000032:analysis*; D017962:alpha-Linolenic Acid / Q000097:blood*
chemical_list: D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D044243:Linoleic Acids, Conjugated; D009829:Oleic Acids; D017962:alpha-Linolenic Acid; D016718:Arachidonic Acid; D015118:Eicosapentaenoic Acid; C050413:11-octadecenoic acid