Practical Use of Feed Enzymes for Turkeys and Broilers

Abstract

The use of feed enzymes for poultry is a common practice in Europe, and there is a growinginterest in their use inNorth America. This interest in feed enzymes is a reflection of changing attitudes in society and the economic climate of the feed industry. Consumer attitudes are tending toward a drug-free, all natural food supply. This means that poultry producers will eventually need to move away from the use of pharmaceutical feed additives to maintain consumer confidence. The use of products like enzymes and direct feed microbids as additives are more acceptable to consumers, probably because of their familiarity with such products in common foods and household materials. Moreover, as environmental concerns about animal waste disposal increase, enzymes are more frequently being considered as a means of reducing manure output and nutrient excretion, particularly excess phosphorus, nitrogen, copper, and zinc. An increasing diversity of by-products from the food industry (e.g., from grain milling, animal processing, brewery fermentation,and recycled waste) are used as feed ingredients. Enzymes can be used to improve the nutritional value of such by-products and perhaps reduce the variability commo~ily associated with such products. Finally, enzymes could be used to maximize the efficiency of feed utilization by reducing the effects of antinutritional factors, reduce feed manufacturing costs, and reduce the variability of nutrient bioavailability in feed. Supplemental enzymes could be useful in reducing some of the limitations on the productive value of poultry feed. These limitations include: 1) the cost of highly digestible, nutrient dense feed; 2) dietary fiber content, particularly fibrillar polysaccharides (cellulose), matrix polysaccharides (pectins, hemicellulose, and glycoproteins), and encrusting material (lignin); 3) interactions among different ingredients, nutrients, and bird characteristics; and 4) antinutritional factors, such as phytin, toxins, tannins, natural chelates, etc. With regard to these inherent limitations, the potential applications of enzymes in poultry feed include: 1) supplementing or complementing the endogenous enzyme production of birds; 2) increasing the digestibility of fiber components; 3) rendering nutrients more available for digestion; 4) reducing the effects of antinutritional factors; and 5) allowing greater flexibility and accuracy in feed formulation, reducing feed cost, and maintaining bird performance.