title: Effect of vitamin E on milk composition of grazing dairy cows supplemented with microencapsulated conjugated linoleic acid.
abstract: The objective of this study was to evaluate the effect of vitamin E on the fat content and fatty acid profile of grazing dairy cows supplemented with microencapsulated conjugated linoleic acid. Eight New Zealand Holstein cows in a rotational grazing system were used, in a crossover design, randomly assigned to four treatments: control (base diet with microencapsulated conjugated linoleic acid) and three levels of vitamin E (control with 4,000; 8,000; and 12,000 IU/cow per day). All the cows received a supplement apportioning 5 g of cis-9, trans-11, and 5 g of trans-10, cis-12 of conjugated linoleic acid. Moreover, they each received 4-kg dry matter (DM) concentrate and 3.2-kg DM corn silage every day. There were no differences in dry matter intake, milk production, milk composition (fat, protein, and lactose), or fatty acid profile as an effect of vitamin E, and fat content remained under 3 % in all treatments. Therefore, under the conditions that this experiment was carried out, high concentrations of vitamin E in the diet of grazing dairy cows do not inhibit milk fat depression associated with conjugated linoleic acid. It also has no effect on the fatty acid profile of the milk.
authors.affiliation: Programa de Ganadería-Colegio de Postgraduados, Carretera México-Texcoco, Km 36.5, C.P.56230, Montecillo, Texcoco, Mexico.
authors.forename: Monica
authors.initials: M
authors.lastname: Ramírez-Mella
authors.forename: Omar
authors.initials: O
authors.lastname: Hernández-Mendo
authors.forename: Efren Jacinto
authors.initials: EJ
authors.lastname: Ramírez-Bribiesca
authors.forename: Ricardo Daniel
authors.initials: RD
authors.lastname: Améndola-Massiotti
authors.forename: María M
authors.initials: MM
authors.lastname: Crosby-Galván
authors.forename: Juan A
authors.initials: JA
authors.lastname: Burgueño-Ferreira
mesh_terms: D000818:Animals; D002417:Cattle / Q000378:metabolism*; D018592:Cross-Over Studies; D004435:Eating / Q000502:physiology; D005260:Female; D044243:Linoleic Acids, Conjugated / Q000378:metabolism*; D008800:Mexico; D008892:Milk / Q000737:chemistry* / Q000187:drug effects*; D011897:Random Allocation; D014810:Vitamin E / Q000494:pharmacology*
chemical_list: D044243:Linoleic Acids, Conjugated; D014810:Vitamin E