Linseed oils with different fatty acid patterns in the diet of broiler chickens

The effect of 1, 3, 5 or 7% of linseed oil on the performance and content of nutrients in meat was studied in an experiment with broiler chickens from 25 to 40 days of age. Oils made either of seeds of the cultivar Atalante (A; groups A1; A3; A5; A7) with a high content of α-linolenic acid or of the cultivar Lola (L) with a predominating content of linoleic acid (L1; L3; L5; L7) were used. The diets were formulated to maintain a constant energy/protein ratio. As compared with the groups receiving 1% and 3%, body weight gains were higher in the groups receiving 5% and 7% of oils in the feed mixture (P < 0.01). A lower feed consumption per unit of weight gain was also recorded in the groups with 7% and 5% of oils than in the groups receiving 1% and 3% (P < 0.01). The content of protein in breast meat in the group with 7% was lower than in the groups with 1% and 5% (P < 0.05). There were no differences in the contents of protein in thigh meat. Similarly, no differences were found out in the contents of fat in thigh and breast meat. In thigh meat, the values of ether extract were always significantly higher (P < 0.01) and those of protein content significantly lower (P < 0.01) than in breast meat. There were no significant differences in basic production parameters, breast and thigh meat percentages in body weight, and in the dry matter, ether extract and crude protein contents in meat between the groups receiving linseed oil with different levels of n-6 and n-3 polyunsaturated fatty acids.