title: Effects of conjugated linoleic acid on growth performance, feed conversion efficiency, and subsequent carcass quality in broiler chickens.
abstract: The effect of dietary conjugated linoleic acid isomers (CLA) on growth performance, carcass composition, fatty acid composition of adipose and muscle tissues, and serum lipoproteins was investigated in broiler chickens. A total of 160 (eighty male and eighty female) chickens were allocated to four dietary treatments (0.0, 0.5, 1.0, and 1.5 % CLA) and fed a standard starter diet from 8 to 21 d, and a grower-finisher diet from 22-42 d. When determined for the total period 8-42 d, feed intake and body weight gains of broiler chickens were significantly reduced (from 3.31 to 3.12 kg and from 1615 to 1435 g respectively; P < 0.05), particularly at the 1.5 % dietary CLA level. Feed conversion efficiency and carcass yield values showed no significant effects of dietary CLA. Abdominal fat deposition was significantly reduced (from 2.68 to 1.78 %; P < 0.05), the relative proportion of breast muscles was unaffected, and that of leg muscles significantly increased (from 19.0 to 20.6 %; P < 0.05). The concentration of CLA isomers (% of total methyl esters of fatty acids) increased linearly in tissue samples from broilers fed 0.5, 1.0, and 1.5 % dietary CLA. The relative proportions of saturated fatty acids (16:0, 18:0) were significantly (P < 0.01) increased, and those of monounsaturated (16:1, 18:1) and polyunsaturated fatty acids (18:2, 20:4 in muscle tissues) significantly (P < 0.05) reduced. Total serum cholesterol concentrations reached a maximum in broilers fed 1.0 % CLA and then decreased slightly (from 141.73 to 136.47 mg/dl; P < 0.01). The same was true also for HDL-cholesterol (from 113.58 to 109.97 mg/dl; The HDL cholesterol:total cholesterol ratio and serum triacylglycerol concentration was unaffected. In conclusion, feeding CLA to broiler chickens resulted in substantial incorporation of CLA isomers into their tissue lipids, thus providing a potential CLA-rich source for human consumption.
authors.affiliation: Department of Animal Nutrition, Institute of Animal Production, 32-083 Balice, Poland.
authors.forename: B
authors.initials: B
authors.lastname: Szymczyk
authors.forename: P M
authors.initials: PM
authors.lastname: Pisulewski
authors.forename: W
authors.initials: W
authors.lastname: Szczurek
authors.forename: P
authors.initials: P
authors.lastname: Hanczakowski
mesh_terms: D000005:Abdomen; D000273:Adipose Tissue / Q000378:metabolism; D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002645:Chickens / Q000378:metabolism* / Q000502:physiology; D004435:Eating / Q000187:drug effects; D005227:Fatty Acids / Q000378:metabolism; D005260:Female; D006128:Growth / Q000187:drug effects*; D019787:Linoleic Acid / Q000494:pharmacology*; D008074:Lipoproteins / Q000097:blood; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism
chemical_list: D005227:Fatty Acids; D008074:Lipoproteins; D019787:Linoleic Acid