Effects of dietary n-3 polyunsaturated fatty acids and ... - FINS

1 st WorkshopXIII International Feed Technology SymposiumThis pollution is most drastically present in the most developed countries that havepolluted the environment and the soil so much, that they now must revise theiragricultural production structure.Principally, the use of specific additives in animal feed is usually applied in those caseswhen certain problems connected to some production level or the animal health need tobe overcome. This includes a group of non-nutritive ingredients which regulate the pHvalue, the growth, modifies metabolism processes etc. (Hutjens, 1991). For example, ifsuch additives are used in the feed of dairy cows, the following factors must beconsidered in order to justify their use: obtaining of the appropriate effect, economic andobtained rationale and the desired effect. When some of the additives is included intocow feed a change in the a certain performance is expected: larger milk production, achange in the milk contents, better dry matter consumption, stimulating the synthesis ofmicro-biological proteins or the evaporable fatty acids, improved digestion, pHstabilization, improved growth, reduction of heat stress, health improvement in the formimmunity improvement.Using live yeast cells in domestic animal feedYeast represents a food additive which is getting increasingly more attention lately. It isbecoming increasingly present in commercial vitamin and mineral mixtures. Its highnutritive value is reflected in the rich presence of enzymes, fatty acids, B vitamin,unknown growth factors and amino acids (more than 40% of the dry matter). Includingyeast in ruminant and non-ruminant meals, more efficient use of celluloses and othernutritive substances as well as a higher daily growth (Sretenović and associates 2001).Yeast cells also absorb micro-toxins from feed and help with the absorption of mineralssuch as phosphor, magnesium, calcium, copper, potassium, zinc and manganese(Hutjens, 2005).Having in mind the fact that many countries prohibit the use of non-absorptiveantibiotics for domestic animal feed, yeast is being increasingly used in ruminant feed aspro-biotic. Yeasts can stimulate the development of other microorganisms in contrast toantibiotics which inhibit the growth of microbes. The importance of yeast higher forruminants than non-ruminants due to their specific digestive tract which is characterizedby the presence of various microorganism populations. Yeast is a safe, natural productwhose useful effects are notable for the Saccharomyces cerevisiae culture which iswidely used as additives in animal feed. Besides the numerous positive effects, yeastregulates the pH of the rumen, uses oxygen as aerobes and stimulates the anaerobicactivity of the rumen, creating a source of nutritive materials and vitamins for rumenmicroorganisms. Yeast has a specifically positive effect on the improvement of cellularactivity which is highly important for ruminants. Besides, yeast helps with thestabilization of bio chemical processes in the rumen and thereby positively influences thegeneral health of the animals and their production results.32