Performance, meat quality, intramuscular fatty acid profile, rumen characteristics and serum parameters of lambs fed microencapsulated or conventional linseed oil

Microencapsulated linseed oil (MLO) has been used in diets to enhance the omega-3 fatty acid concentration of meat in beef cattle without negatively affecting ruminal microbials and digestion; however, the growth performance, meat quality, intramuscular fatty acid profile, and rumen characteristics in response to MLO have not been examined in sheep. Thus, the aim of the present study was to evaluate the effects of microencapsulated or conventional linseed oil supplement on growth performance, meat quality, intramuscular fatty acid profile, rumen characteristics and serum parameters in Small-tailed Han sheep. Eighteen 5-months-old male sheep (25.31 ± 1.31 kg) were allocated to three groups. After seven days of adaptation to a basal diet, fed for 80 days, the treatments allocated were (1) basal diet (CON); (2) basal diet with added 2% linseed oil (LO); (3) basal diet with added 4% MLO. The results showed that treatments had no effects on growth performance (P ≥ 0.10). Compared to CON and MLO group, the pH24 h of the longissimus dorsi (LD) muscle in LO group was lower (P = 0.07), while the shear force was higher (P = 0.01). Compared to CON group, the addition of linseed oil increased proportions of C17:1, C18:2 n-6c, total polyunsaturated fatty acids (PUFA), PUFA/saturated fatty acids and total n-6, while it decreased the proportion of C17:0, C16:1 and C18:1 c-9 in LD muscle (P < 0.10). The lambs in LO and MLO group had higher proportions of C20:1, C18:3 n-3 and total n-3 in LD muscle than those in CON group (P < 0.10). Compared to CON group, the ruminal pH value of MLO group and the ruminal NH3–N content of LO group were lower (P < 0.10). The total volatile fatty acid, proportion of acetate, and acetate/propionate were deceased in LO and MLO groups (P < 0.05). Furthermore, the two supplements significantly increased the proportions of propionate, butyrate and isovalerate (P < 0.05). Circulating cholesterol and high-density lipoprotein cholesterol concentrations were increased by linseed oil supplementation (P = 0.04). In conclusion, these results indicate that microencapsulated linseed oil did not exhibit any superior effects on muscle fatty acid composition and rumen fermentation of lambs.