title: Milk conjugated linoleic acid response to fish oil supplementation of diets differing in fatty acid profiles.
abstract: The objective of this experiment was to examine the effect of feeding fish oil (FO) along with fat sources that varied in their fatty acid compositions (high stearic, high oleic, high linoleic, or high linolenic acids) to determine which combination would lead to maximum conjugated linoleic acid (cis-9,trans-11 CLA) and transvaccenic acid (TVA) concentrations in milk fat. Twelve Holstein cows (eight multiparous and four primiparous cows) at 73 (+/- 32) DIM were used in a 4 x 4 Latin square with 4-wk periods. Treatment diets were 1) 1% FO plus 2% fat source high in stearic acid (HS), 2) 1% FO plus 2% fat from high oleic acid sunflower seeds (HO), 3) 1% FO plus 2% fat from high linoleic acid sunflower seeds (HLO), and 4) 1% FO plus 2% fat from flax seeds (high linolenic; HLN). Diets formulated to contain 18% crude protein were composed of 50% (dry basis) concentrate mix, 25% corn silage, 12.5% alfalfa haylage, and 12.5% alfalfa hay. Milk production (35.8, 36.3, 34.9, and 35.0 kg/d for diets 1 to 4) was similar for all diets. Milk fat percentages (3.14, 2.81, 2.66, and 3.08) and yields (1.13, 1.02, 0.93, and 1.08 kg/d) for diets 1 to 4 were lowest for HLO. Milk protein percentages (3.04, 3.03, 3.10, and 3.08) and dry matter intake (DMI) (25.8, 26.0, 26.2, and 26.2 kg/d) for diets 1 to 4 were similar for all diets. Milk cis-9,trans-11 CLA concentrations (0.70, 1.04, 1.70, and 1.06 g/100 g fatty acids) for diet 1 to 4 and yields (7.7, 10.7, 15.8, and 11.3 g/d) for diets 1 to 4 were greatest with HLO and were least with HS. Milk cis-9,trans-11 CLA concentrations and yields were similar for cows fed the HO and the HLN diets. Similar to milk cis-9,trans-11 CLA, milk TVA concentration (1.64, 2.49, 3.74, and 2.41 g/100 g fatty acids) for diets 1 to 4 was greatest with the HLO diet and least with the HS diet. Feeding a high linoleic acid fat source with fish oil most effectively increased concentrations and yields of milk cis-9,trans-11 CLA and TVA.
authors.affiliation: Dairy Science Department, South Dakota State University, Brookings 57007-0647, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: AbuGhazaleh
authors.forename: D J
authors.initials: DJ
authors.lastname: Schingoethe
authors.forename: A R
authors.initials: AR
authors.lastname: Hippen
authors.forename: K F
authors.initials: KF
authors.lastname: Kalscheur
mesh_terms: D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle / Q000502:physiology*; D004032:Diet; D004041:Dietary Fats / Q000008:administration & dosage*; D004044:Dietary Proteins / Q000008:administration & dosage; D005227:Fatty Acids / Q000008:administration & dosage* / Q000032:analysis; D005260:Female; D005395:Fish Oils / Q000008:administration & dosage*; D006368:Helianthus; D007774:Lactation; D019787:Linoleic Acid / Q000008:administration & dosage / Q000032:analysis*; D008055:Lipids / Q000032:analysis; D000455:Medicago sativa; D008892:Milk / Q000737:chemistry*; D019301:Oleic Acid / Q000008:administration & dosage; D009829:Oleic Acids / Q000032:analysis; D012639:Seeds; D012820:Silage; D013229:Stearic Acids / Q000008:administration & dosage; D003313:Zea mays; D017962:alpha-Linolenic Acid / Q000008:administration & dosage
chemical_list: D004041:Dietary Fats; D004044:Dietary Proteins; D005227:Fatty Acids; D005395:Fish Oils; D008055:Lipids; D009829:Oleic Acids; D013229:Stearic Acids; D017962:alpha-Linolenic Acid; D019301:Oleic Acid; C031183:stearic acid; D019787:Linoleic Acid; C050413:11-octadecenoic acid