Document Type : Research Paper
Authors
Abstract
A study with 56 male lambs of Lori-Bakhtiari sheep breed was carried out to investigate the effect of selection to decrease fat on the fatty acids composition in the subcutaneous fat and fat-tail adipose tissue. Subcutaneous fat and fat-tail fat samples were obtained from the back of left side of carcass and fat-tail, respectively. Total 112 samples of subcutaneous fat and fat-tail adipose tissue were obtained from 56 carcasses at six month of age. The fatty acid composition of subcutaneous fat and fat-tail were analyzed after fat extraction by gas chromatography. Data were analyzed using SAS statistical program. Proportion of palmitic (C16:0) in fat tissue significantly (P<0.05) decreased and linoleic (C18:2) significantly increased at the end of the selection program.While body weight lambs was higher at the end of the selection program, unsaturated fatty acids was higher in carcass fat. Ratios of poly unsaturated fatty acids to saturated fatty acids were significantly higher incarcass fat at the end of the selection. Desirable fatty acids and ratio of (C18:0+C18:1)/C16:0 did not significant increase at constant weight. Proportion of palmitic (C16:0), stearic (C18:0)and total saturated fatty acids were significantly higher in subcutaneous fat but oleic fatty acid (C18:1)was significantly higher in fat-tail. Ratios of unsaturated fatty acids to saturated fatty acids, desirable fatty acids and ratio of (C18:0+C18:1)/C16:0 were significantly (P<0.05) higher in fat-tail than subcutaneous fat at constant weight. Inconcluded, selection for decreased carcass fat cause improve fatty acid composition of fat tissue.
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