Effect of antinutritive factors in the feed (phytic acid, nonstarch polysaccharides) and kind of trace element forms (inorganic vs organic) was presented on the basis of literature review. Phytic acid, through formation of indigestible complexes with microelements, significantly decreases its utilization by the organism. Also non-starch polysaccharides showed of ten similar influence. Organic forms of trace elements generally are characterized by higher bioavailability than their inorganic forms.
Principles of the use of enzymes as a new category of feed additives in poultry and pig nutrition are briefly explained. The effects of various enzyme preparations on the nutritive value of poultry diets based on low-energy cereals such as barley, oats, rye and triticale are reviewed. Effectiveness of enzymatic additives to diets used in feeding of piglets and growing-finishing pigs is also presented. On the basis of the cited data enzymes preparations seem tobe more effective in poultry than pig nutrition. Main reasons for differences between the reactions of poultry and pigs to enzyme addition are indicated. The results of addition of enzymatic preparation to poultry diet rich in legume seeds are also discussed.