Determining the effect of the fat-tail and carcass weight on meat fatty acid composition of Iranian lambs

Fat-tailed sheep are widely distributed around the globe, probably because of their ability to adapt and endure harsh environmental conditions. Climate change and increasing demand for protein mean these animals are a vital part of our food chain. Despite this, little is known about the composition of their meat. The aim of our study was to investigate the effect of the fat-tail and carcass weight on chemical composition and fatty acid profile of Longissimus dorsi muscle of lambs. We compared sixty male lambs from three fat-tail weight classes (tailed, light fat-tailed, heavy fat-tailed) and two carcass weight ranges (6-13 kg, designated light-LC; 13-21 kg, designated moderate-MC). These lambs were randomly selected from a local flock grazed under standard commercial conditions in Mazandran, Iran. Our results showed that heavy fat-tailed (HF) lambs deposit less intramuscular fat than light fat tailed (LF) and tailed (T) lambs (p < 0.05). Lambs with moderate carcasses (MC) weight, deposited more intramuscular fat compared with lambs which had low carcass weight (p < 0.001). Polyunsaturated fatty acids (PUFA) are considered healthier than saturated fatty acids (SFA). LC lambs had higher PUFA:SFA and lower n-6:n-3PUFA ratio (p < 0.001), than MC lambs. There were no significant differences in the fatty acid profile of lambs due to the different fat tail weights. In conclusion, lambs with higher carcasses weight and intramuscular fat, had higher levels of unfavorable fatty acids. However, changes in intramuscular fat did not affect the fatty acid profile of lambs with different tail weights.