The effect of genotype on the chemical and fatty acid composition of the <i>Quadriceps</i> femoris muscle in extensively fattened lambs

Abstract

Abstract. The aim of the experiment was to define the effect of a Suffolk-sired genotype on the chemical composition and fatty acid profile of the Quadriceps femoris muscle in fattened lambs reared under organic farming conditions. Three different genotypes of Suffolk-sired crossbreds were included in the experiment: F1 Suffolk-Charollais (SF 50 CH 50, n=10), F11 Suffolk-Charollais (SF 75 CH 25, n=10) and F1 Suffolk-Improved Walachian (SF 50 IW 50, n=10). The genotype did not have any effect on age at slaughter, average daily gain or carcass dressing percentages. However, the SF 75 CH 25 lambs displayed a lower live weight at slaughter (P<0.05), lower cold carcass weight (P<0.05) and lower protein content in muscle (P<0.05) than both of the other genotypes. They also had a lower content of kidney fat compared to the SF 50 CH 50 (P<0.01). The F11 Suffolk-Charollais lambs showed a higher proportion of C12:0 (P<0.01), C14:0 (P<0.01) and C16:0 (P<0.05) than the other two genotypes. A higher proportion of C18:0 was found in the SF 50 CH 50 lambs (P<0.05). The total content of saturated fatty acids (SFA) was higher in the SF 75 CH 25 crossbreds (P<0.05). The genotype also affected the content of C16:1 having its highest presence in the SF 75 CH 25 lambs while the lowest presence was found in the SF 50 CH 50 lambs (P<0.01). Between these two genotypes there were also found different proportions of C18:1 having its higher presence in SF 50 CH 50 lambs (P<0.05). Moreover, the IW type lambs had a lower SFA proportion and lower values of atherogenic and thrombogenic indexes and a higher polyunsaturated/saturated fatty acid (P/S) ratio in their meat than lambs of the CH genotypes (P<0.05). As for crossing between the Suffolk and Charollais breeds, a favourable fatty acids profile of meat was observed in the F1 crossbred as compared to the F11 crossbred.