title: Characterization of 18:1 and 18:2 isomers produced during microbial biohydrogenation of unsaturated fatty acids from canola and soya bean oil in the rumen of lactating cows.
abstract: Ruminal production of biohydrogenation intermediates in response to unsaturated oils was assessed using 24 Jersey cows fed a control diet or the control diet supplemented at 35 g/kg dry matter (DM) with canola, soya bean, or a mixture of equal amounts of canola plus soya bean oil for 4-weeks. Total fatty acid content averaged 63 or 35 g/kg DM for oil-supplemented diets or control. Oleic acid accounted for 6, 29, 21 or 12 g/kg DM in the control, canola, mixture, or soya bean oil diet, respectively. Linoleic acid averaged 17, 19, 26, or 33 g/kg DM and linolenic acid 5, 5, 6 or 8 g/kg DM for control, canola, mixture, or soya bean oil. Concentrations of cis12-, trans11-, trans13+14, and trans15-18:1 were 0.81, 2.99, 2.24, and 0.73 mg/g rumen fluid, respectively, in response to soya bean oil and were 126, 90, 45, and 38% greater compared with other diets. Trans11cis15-, cis9trans11- and cis9 cis11-18:2 also were greater when soya bean oil (0.30, 0.34 and 0.01 mg/g, respectively) was fed compared with other treatments (0.12, 0.21 and 0.004 mg/g, respectively). Feeding canola oil resulted in greater concentrations of trans4-, trans5-, trans6+7+8-, trans9- and trans10-18:1 (0.20, 0.25, 0.87, 0.39 and 0.70 mg/g, respectively) compared with other diets (0.09, 0.15, 0.36, 0.20 and 0.46 mg/g, respectively). Trans10cis12-18:2 concentration did not differ as a result of diet and averaged 0.002 mg/g rumen contents. The pattern of 18:1 and 18:2 isomers formed during ruminal biohydrogenation depends greatly on dietary profile of unsaturated fatty acids.
authors.affiliation: Dairy Science Department, Virginia Tech, Blacksburg, VA 24061-0315, USA. jloor@uiuc.edu
authors.forename: J J
authors.initials: JJ
authors.lastname: Loor
authors.forename: A B P A
authors.initials: AB
authors.lastname: Bandara
authors.forename: J H
authors.initials: JH
authors.lastname: Herbein
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle / Q000378:metabolism*; D005229:Fatty Acids, Monounsaturated / Q000008:administration & dosage / Q000737:chemistry*; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism*; D005260:Female; D006865:Hydrogenation; D007536:Isomerism; D007774:Lactation / Q000378:metabolism; D000074262:Rapeseed Oil; D012417:Rumen / Q000737:chemistry / Q000378:metabolism* / Q000382:microbiology; D013024:Soybean Oil / Q000008:administration & dosage / Q000737:chemistry*
chemical_list: D005229:Fatty Acids, Monounsaturated; D005231:Fatty Acids, Unsaturated; D000074262:Rapeseed Oil; D013024:Soybean Oil