title: Conjugated linoleic acid-enriched beef production.
abstract: Canadian beef consumption is approximately 31 kg per annum, or a third of all meats consumed. Beef is a nutrient-rich food, providing good quality protein, vitamins B-6 and B-12, niacin, iron, and zinc. However, animal fats have gained the reputation of being less healthy. The identification of the anticarcinogenic effects of beef extracts due to the presence of conjugated linoleic acid (CLA) has heightened interest in increasing the amount of CLA deposited in beef. Beef cattle produce CLA and deposit these compounds in the meat; thus, beef consumers can receive bioformed CLA. Beef contains both of the bioactive CLA isomers, namely, cis-9, trans-11 and trans-10, cis-12. The relative content of these CLA isomers in beef depends on the feeds consumed by the animals during production. Feeding cattle linoleic acid-rich oils for extended periods of time increases the CLA content of beef. Depending on the type and relative maturity of the pasture, beef from pasture-fed cattle may have a higher CLA content than beef from grain- or silage-fed cattle. In feedlot animals fed high-grain diets, inclusion of dietary oil along with hay during both the growth and finishing phases led to an increase in CLA content from 2.8 to 14 mg/g beef fat, which would provide 77 mg CLA in an 85-g serving of beef. The CLAs appear to be concentrated in intramuscular and subcutaneous fat of beef cattle, with the CLA trans-10, cis-12 isomer being greater in the subcutaneous fat.
authors.affiliation: Agriculture and Agri-Food Canada, Lethbridge, AB, Canada. mirp@agr.gc.ca
authors.forename: Priya S
authors.initials: PS
authors.lastname: Mir
authors.forename: Timothy A
authors.initials: TA
authors.lastname: McAllister
authors.forename: Shannon
authors.initials: S
authors.lastname: Scott
authors.forename: Jennifer
authors.initials: J
authors.lastname: Aalhus
authors.forename: Vern
authors.initials: V
authors.lastname: Baron
authors.forename: Duane
authors.initials: D
authors.lastname: McCartney
authors.forename: Edward
authors.initials: E
authors.lastname: Charmley
authors.forename: Laki
authors.initials: L
authors.lastname: Goonewardene
authors.forename: John
authors.initials: J
authors.lastname: Basarab
authors.forename: Erasmus
authors.initials: E
authors.lastname: Okine
authors.forename: Randall J
authors.initials: RJ
authors.lastname: Weselake
authors.forename: Zahir
authors.initials: Z
authors.lastname: Mir
mesh_terms: D000821:Animal Feed; D000818:Animals; D002417:Cattle; D005527:Food, Fortified; D006801:Humans; D044243:Linoleic Acids, Conjugated / Q000032:analysis*; D008460:Meat / Q000032:analysis*; D008892:Milk / Q000737:chemistry; D009747:Nutritional Physiological Phenomena
chemical_list: D044243:Linoleic Acids, Conjugated