IMPROVING THE NUTRITIVE VALUE OF FORAGE BY APPLYING EXOGENOUS ENZYME

The use of exogenous enzymes in animal nutrition dates back to the mid-1920s, however, nowadays the development of interdisciplinary sciences exploiting molecular methods create new opportunities and deliver new tools to assess effectiveness of their utilization. Effectiveness of enzymes in animal nutrition depends on (i) type, (ii) source, (iii) level of supplemented enzymes, (iv) the type of diet fed, (v) animal health and (vi) animal productivity. In most tropical countries, the ruminant feed is based on fibrous resources with a cell wall content between 40 and 70% of dry matter, of which less than 50% is quickly digested, which generates high excretion of nutrients to the environment and low productivity in their production systems. Recently, forage cell wall digestibility has undergone significant improvements through exogenous enzyme technology. In terms of enzyme technology, the two most popular enzyme complexes are those of the cellulase and hemicellulase families, generally known to be multi-component enzymes that when added to forage could possibly assist in the preservation of forages, especially silage. Enzymes can be applied to straw in their pure form or through inoculation with appropriate cell wall degrading microbes. It is acknowledged that enzyme preparations with specific activities can be used to drive specific metabolic and digestive processes in the gastrointestinal tract and may increase natural digestive processes to improve the availability of nutrients and feed intake thereafter The use of enzymes has a positive relation with palatability, feed intake, rumen microbial N synthesis, digestibility, and improves animal performance as milk production, live weight gain, feed efficiency and immunity. Enzyme preparations for ruminants are produced through microbial fermentation, beginning with seed culture and growth media. In general, Bacillus subtilis, Lactobacillus acidophilus, L. plantarum, and Streptococcus faecium, spp. are the source of bacterial enzymes. Fungal enzymes generally come from Aspergillus oryzae, Trichoderma reesei, and Saccharomyces cerevisiae species. Key words: Exogenous, Enzyme, Forage, nutritive value; DOI: 10.7176/JBAH/14-3-01 Publication date: September 30 th 2024