Nutritional and anti-nutritional composition of rapeseed meal and its utilization as a feed ingredient for animal

摘要

Rapeseed cake and meal, a by-product of rapeseed, is one of the most important protein feedstuffs. Quality characeristics of rapeseed meal are given as follows: (1) The energy value of rapeseed meal is at variance, for which it is affected by its residual oil,crust and crude fiber content. (2) Rapeseed meal is an excellent protein source owing to its relatively high protein level (30%-40%),lysine, methionine and tryptophan levels as well as its low digestibility. (3) The calcium, phosphorus, selenium, iron and manganese contents in rapeseed meal are very high, but up to 65% of the P content is abound in P-phytate and thus reducing it bioavailability. (4) High levels of nicotinic acid and choline as well as low carotenoid and vitamin D levels are the main vitamins characteristics of rapeseed meal. Furthermore, variety, squeeze technique, anti-nutritional factors and its levels will also influence the nutritional value of rapeseed meal. While the main anti-nutritional factors in rapeseed meal include glucosinolates, sinapine,sinapic acid, tannin, phytic acid and crude fiber, there are some physical, chemical, biological and crop breeding methods to deal with the toxicity in rapeseed meal, of which the crop breeding is the most successful. Chinese "Double low" rapeseed and Canadian canola are main new varieties. Rapeseed meal has been widely used in the diet of some animals, and the amounts incorporated in diets of poultry, swine and cattle are usually 8%-15%, 3%-15% and 5%-20%, respectively. Presently, the anti-nutritional factors in common rapeseed meal, especially the glucosinolaates and sinapic acid, are the main limiting factors for its wider application, while popularization and application for new species will bring into an available approach in solving those problems.