Effects of raw and modified canola lecithins compared to canola oil, canola seed and soy lecithin on ruminal fermentation measured with rumen simulation technique

The effects of four different canola lecithins applied at proportions of 30 g fatty acid kg(-1) diet were compared with diets containing either no add itional lipid or the same amount of fatty acids from canola seed, pure cano la oil and deoiled soy lecithin, respectively. Four types of canola lecithi n with increasing dispersibility in water were used: raw; deoiled; deoiled/ hydrolysed; and hydrolysed/acetylated lecithin. The complete rations consis ted of maize silage, hay and concentrate, and were simultaneously applied i n 10 days lasting experimental periods in rumen simulation technique (Rusit ec) with eight consecutive replications each. Like canola seed and pure can ola oil, the lecithins also increased rumen fluid pH and propionate proport ion of volatile fatty acids (VFA) whereas total VFA concentration and butyr ate proportion were reduced. The level of effect of the canola lecithins on VFA concentration as well as on bacteria and ciliate count depended on the type of lecithin. A decrease in ammonia concentration was found with canol a oil and all lecithins but not with canola seed. Compared with the unsuppl emented diet, canola oil decreased both acetate to propionate ratio and met hane release. The effects against methane were lower with canola lecithins, particularly when deoiled. The use of the lecithins did not affect fibre d egradation, whereas apparent protein degradation was significantly lower th an in the other treatments. In spite of its much higher linoleic acid conte nt, deoiled soy lecithin had quite similar effects as deoiled canola lecith in. Overall, canola lecithins, particularly in a modified form, could be ad vantageous in comparison with pure oils in ruminant nutrition in terms of n utrient degradation. (C) 2000 Elsevier Science B.V. All rights reserved.