Thirty-four not castrated lambs, 16 Santa Ines (SI) and 18 ½ Dorper + ½ Santa Ines (½ D + ½ SI), were slaughtered with different subcutaneous fat thicknesses to verify the effect of genotype and fat thickness on chemical composition of the meat. The lambs remained confined, from weaning to slaughter, and they were fed with complete pelleted ration calculated for daily weight gain of 0.3 kg. Ultrasound evaluations were performed between the 12th and 13th ribs in the loin area. The slaughter was carried out when the lambs reached the thickness of fat pre-determined: 2.0, 3.0 and 4.0 mm. There were differences in the total lipids of the meat between the genetic groups (SI: 4.78g / 100g; ½ D ½ + SI: 6.45g / 100g) and fat thickness at slaughter (2.0mm: 4.77g / 100g; 3.0mm: 5.20g / 100g and 4.0mm: 6.86g / 100g). The contents of fatty acids differed in the different fat thicknesses at slaughter (2.0mm: 26.52g/100g; 3.0mm: 27.07g/100g e 4.0mm: 24.63g/100g). It was observed the presence of an isomer of Conjugated Linoleic Acid, C18: 1n 9cis, 11trans. Analyzing the total concentration of unsaturated fatty acids, it was observed that the different thicknesses of fat signifycantly affected the concentration of polyunsaturated fatty acids (2.0mm: 8.36g/100g; 3.0mm: 8.54g/100g e 4.0mm: 11.18g/100g). Meat from lambs proved highly beneficial in lipid content and an isomer of CLA. Under the conditions of the experiment the lamb meat slaughtered with 4.0mm thickness of subcutaneous fat showed better increase of polyunsaturated fatty acids in relation to the other, thus improving the nutritional quality of the meat making it more suitable for human consumption.
CLA; lipids; sheep; unsaturated fatty acid