COMPARISON OF LINSEED OIL WITH ANIMAL TALLOW AS A SOURCE OF ENERGY IN BROILER DIETS

Two experiments were conducted to compare linseed oil and animal tallow as sources of energy for broiler chicks. In the first experiment, the amount of protein was held constant and the calorie-to-protein ratio changed with the amount of supplementation of linseed oil or tallow. The calorie-to-protein ratios used were 82, 97, 112, 127, and 142. In the second experiment, the calorie-to-protein ratio was held constant at 138. In experiment 1, each increase in the energy level of the diet up to 15% addition of combinations of energy sources resulted in improved 4-wk weights and feed efficiency. Four-week body weight of the chicks fed the 15% combinations was not statistically different from that of chicks fed 10% levels of each energy source or combination of sources at P < 0.05. The 20% combination of energy sources did not increase body weight over that obtained with 10 or 15% but did improve feed efficiency. In experiment 2, there were fewer differences in body weight than in experiment 1, those of the un-supplemented group being less (P < 0.05) than those of all the supplemented groups, and those of the 5% tallow and 20% combination being less (P < 0.05) than those of the 10% tallow–5% linseed oil treatment. The feed-to-gain ratios, in general, decreased as the energy level increased. There were few significant differences between energy sources when compared at the same level of supplementation, but, in general, linseed oil tended to be superior to animal tallow in supporting growth and decreasing the amount of feed required per unit of gain.