Effect of dietary fsh and rapeseed oils on sensory and physicochemical characteristics of pig M. longissimus dorsi and fatty acid composition

The study evaluated the effect of fish and rapeseed oils in pig diets on the sensory and physicochemical characteristics of M. longissimus dorsi and its fatty acid composition. Both oils were added to a humus-mineral medium and blended with feed ingredients. Four groups of pigs, 54 per group, were fattened from 30 to 100 kg on diets that were either not supplemented (control, G I), or supplemented with oil (2%): G II-rapeseed, G III-fish, and G IV fish from 30 to 80 kg (growing) and rapeseed from 80 to 100 kg (finishing). Differences (P0.01) were found in the experimental groups (in comparison with G I) in meat juiciness and taste, pH, crude fat and total cholesterol, all in favour of the experimental diets. In relation to fatty acids, the differences (P0.01) concerned C 10:0 , C 18:3 n-3, C 18:3 n-6, C 20:1 n-9, C 20:2 n-6, C 20:4 n-6, C 20:5 n-3 (EPA), C 22:5 n-3 (DPA), and C 22:6 n-3 (DHA). In the experimental groups, PUFA increased by 34-36%, the sum of n-3 increased 5-6.6 times, and the n-6/n-3 ratio decreased 4-5 times (P0.01). Colour, aroma, tenderness, dry matter, total protein, SFA, UFA, MUFA, DFA and OFA were similar in all of the groups. The best sensory results were found in pigs from G IV fed with two oils, fish (growing) and rapeseed (finishing).