Anaerobic enzymes as a new technology in animal feed

Biological treatment is a new method for the improving the nutritive value of lignocelluloses materials which are the most abundant in agricultural residues. The most common cellulolytic microorganisms are fungal cultures (Aspergillus oryzae and Saccharomyces cerevisiae) and actinomycetes and other bacteria which have the ability to produce sufficient amount of cellulase and hemi-cellulase enzymes which are capable of degrading the lignocelluloses material [1]. The biological treatments include bacterial, fungal and enzymatic additives. Each microbial species possesses a unique combination of characteristics, including substrates utilized, types and ratios of fermentation products, and growth yield [2]. The attachment of microbes to feed particles and the nitrogenous substances play important roles in the biosynthesis of protein by different organisms [3]. Thus, in order to increase digestibility of these roughages, it is important to destroy the linkage between cellulose, hemi-cellulose and lignin or to destroy the compact nature of the tissue, so that lignified tissue is separated from non-lignified tissues. There have been attempts to do that by mechanical, chemical or biological treatments and enriching treatments. Whereas, physical treatment means that reducing particle size for ensiling and install-feeding and that reduction of particle size can be achieved using a power driven chopper or a hand operated chaff cutter; this mean that the surface area of non-lignin material exposed to microbial attack in the rumen is increased, thus increasing the rate of digestion, thereby reducing a possible limitation to intake [4] and the smaller the particle size the less scope there is for selection. The use of feed enzymes in feed ruminants has been viewed with considerable skepticism, but in recent years a considerable number of studies on this topic have been conducted. The majority of these experiments were designed with the expectation that a fibrolytic enzyme should increase the degradability of feed in the rumen, and this response has been observed in many of these studies [5, 6]. However, lack of effects [7, 8] or even negative effects [9] have also been detected. These inconsistencies could be attributed to differences in crude enzyme preparations, type of diets fed to the animals and enzymes application methods [10]. Exogenous fibrolityc enzymes might enhance attachment and/or improve access to the cell wall matrix by ruminal microorganisms and by doing so, accelerate the rate of digestion [11]. Due to the importance of forage in ruminant feeding, the possibility of improving its nutritive value by adding exogenous enzymes should be explored. Most of studies with enzyme-treated forages have been conducted with good-quality forages, but limited data are available involving application of exogenous enzymes to fibrous feeds. In this chapter, we aim to help solve this problem with nutritional scientists and their efforts to find methods to improve the utility of these by-products in feeding ruminants. Enzymes have been recently used in the ruminant rations to degrade fiber contents to make it easier for digestion, to be more useful for the micro-organisms and flora which are the main source of the microbial protein in the ruminal media and to reduce the costs of the ration. © 2013 by Nova Science Publishers, Inc. All rights reserved.