Carcass quality, meat chemical and fatty acid composition of lambs fed diets containing extruded soybeans and sunflower seeds

The effects of extruded soybeans (ESB) and sunflower seeds (SFS) on in vivo parameters, slaughter performances, the composition of the lumbar region and hind leg and on the fatty acid composition of these cuts of meat were evaluated in thirty male Sarda lambs divided into six experimental groups, each comprising five members. The six isonitrogenous and isoenergetic diets contained corn, barley, soybean meal and 50% lucerne hay, while ESB and/or SFS were present in the six diets in different proportions: (1) 0–0; (2) 15–0; (3) 7.5–0; (4) 0–10; (5) 0–20; (6) 7.5–10. The trial was carried out on all groups for 90 days (55–145 of age). The lambs were kept in individual pens and fed ad libitum. The lambs were slaughtered and, after being stored for 24 h at 2–4 °C, each right half-carcass was jointed in commercial cuts. The lumbar region and a slice of the hind leg were separated in order to determine the percentages of tissue components. Cooking losses, meat colour and chemical and fatty acid composition of muscles were likewise evaluated. All the results concerning feed intake, live weight gain, feed conversion ratio and slaughter parameters were similar in the six groups and comparable to other findings reported in the literature. The percentages of lean, fat and bone were not affected by diet, except for fat of hind leg in groups 15–0 and 0–20. The chemical composition of lean was different only between the lumbar regions of 15–0 and 7.5–10 groups. Statistically significant differences (P<0.01) were found in the fatty acid composition of muscles, in particular as regards C18:0, and saturated fatty acids were lower in groups 0–20 and 7.5–10. C18:2 and C18:3 and total PUFA contents were significantly higher (P<0.05) or showed an upward trend in the same groups. In hind leg muscles in particular, the C18:2 increased when at least 10% oilseeds was included in the diet.