Fatty acids composition and health indices in different fat and muscle locations of lambs from crossbreeding between Lori-Bakhtiari and Romanov sheep breeds

Abstract

The current study aimed to evaluate the fatty acids (FAs) profile of five different locations in pure Lori-Bakhtiari (LL genotype) fat-tailed sheep and their crosses (RL genotype) with the Romanov-tailed breed. After slaughtering, samples were collected from longissimus thoracis (LT) and semi-membranous (SM) as muscle, and fat-tail (FT), subcutaneous (SC), and abdominal (AB) fat as adipose tissues. After extracting the ether extract of samples according to the recommendations by the AOAC, the fatty acid composition of the samples was determined using gas chromatography. The main FAs were C14:0, C16:0, C18:0, and C18:1 for all locations. These FAs accounted for about 80–88 % and 85–90 % of the total FAs in muscle and adipose tissues, respectively. The results showed that for many of the FAs in muscle tissues, there were no significant differences between the LL and RL genotypes; However, the genotypes had a significant difference in proportions of C14, C16:1, C18:0, C18:3, C20:0, and C20:1 (P < 0.05) in all locations, as the LL genotype had lower C18:0 and C20:0 than the RL genotype.Genotypes did not show significant differences in classic ratios and health indices in muscle tissues and AB fat; While in FT and SC tissues, the genotypes had significant differences regarding saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), the unsaturated fatty acid to saturated fatty acid ratio (U/S), the saturation index (SI), and the trombogenic index (TI). The comparison of fatty acids and indices between muscle (LT and SM) and adipose (FT, SC, and AB) tissues showed that these two tissues were statistically different in terms of many individual fatty acids and indices (P < 0.05; P < 0.01). Also, adipose tissues had different amounts of C12:0 (0.22 vs. 0.45), C15:0 (0.82 vs. 0.36), C16:0 (26.51 vs. 27.73), C16:1 (3.37 vs. 2.75), C17:1 (1.29 vs. 0.49), C18:1c (39.05 vs. 43.80), C18: 1 t (1.57 vs. 0.76), C18: 2n6 (3.15 vs. 3.86), and C20:1 (0.84 vs. 0.58).The n-6/n-3 and h/H ratios were significant difference between fat and muscle tissues (P < 0.05). it can be concluded that RL genotype was not superior than the LL genotype regarding the FAs, the ratios, and health indices. Therefore, crossbreeding native fat-tailed Lori-Bakhtiari sheep with Romanov sheep does not improve the meat quality; however, it can decrease the total body fat content.