Genotype-related variations in subcutaneous fat composition in sheep

The aim of this research was to study the effect of genotype on the fatty a cid composition in adult ewes and 5-to 6-month-old lambs of two mutton bree ds (Suffolk and Pannon Sheep) and Booroola Merino. Samples of subcutaneous fat were obtained by surgical biopsy around the tailhead. Fatty acid compos ition of the adipose fat was determined by gas chromatography. Significant differences (P < 0.05) were found in the fatty acid composition of the adip ose tissue among the three breeds. Suffolk showed a lower (P < 0.05) propor tion of C12 : 0 and C14 : 0 fatty acids than the other two breeds. Consider ing the total quantity of saturated (TSFA) and the total quantity of unsatu rated (TUFA) forty acids, Booroola Merino showed a significantly (P < 0.05) higher proportion of TSFA and lower proportion of TUFA in their adipose ti ssue than the mutton genotypes (Suffolk and Pannon Sheep). Higher proportio ns of C18 : 0, C18 : 3 and C20: 1 (P < 0.05) but lower proportions of C12 : 0, C14 : 0, C16 : 0, C16 : 1 and C18 : 2 (P < 0.05) were found in the subc utaneous fat of adult ewes than in that of their female progeny. Sex differ ences were also observed in the study. The proportions of saturated fatty a cids were higher (P < 0.05) in female lambs than in males of the same age. These results indicate that a genetic approach may be useful to improve fat ty acid composition of carcass lipids in sheep. However, age and sex differ ences also have to be taken into consideration.