A COMPARISON OF CANOLA ACIDULATED FATTY ACIDS AND TALLOW AS SUPPLEMENTS TO A GROUND ALFALFA DIET FOR SHEEP
Experiments were conducted to determine the effects of supplementing ground alfalfa diets with 0, 3, 4, 5 or 10% canola acidulated fatty acids (CAFA) or tallow on digestion in the rumen, and on nutrient digestibility and performance by sheep. Effects of these treatments on in situ dry matter (DMD) and nitrogen (ND) disappearance were measured by the nylon bag technique using rumen-fistulated cattle. DMD was reduced (P < 0.05) for diets containing CAFA at the 5 and 10% levels after 24 and 48 h of incubation in the rumen and for diets containing tallow at all levels after 48 h incubation. ND from the nylon bags was not affected by fat supplementation. A digestibility experiment with 36 mature wethers in a completely randomized design showed no differences (P > 0.05) in dry matter, nitrogen, acid detergent fiber or energy digestibility between unsupplemented and fat-supplemented diets. Neutral detergent fiber digestibility, however, was greater (P < 0.05) for the 3% CAFA, 4% tallow and 10% tallow diets than the control. Fat supplementation did not influence rumen fermentation characteristics such as pH and volatile fatty acid patterns. In a feeding trial with 84 weaned lambs in a completely randomized design, supplementation with 5% CAFA or tallow at 3, 4 and 5% resulted in increased liveweight gain when compared with control (P < 0.05). Average dry matter intakes were similar with all the fat supplemented diets. Key words: Sheep, tallow, canola acidulated fatty acids, alfalfa hay, digestibility