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

1 st WorkshopXIII International Feed Technology Symposiumruminants is mainly new knowledge and possibilities to control physiological processesin the rumen, mainly:Decomposition of quickly fermentable saccharides, mainly starch and its flowthrough rumen into small intestine in an amount, which will enable maximumabsorption of glucose.Continuous decomposition of cell wall parts fractions (cellulose, hemicellulose) andquick transport of non-utilizable particles from rumen; it can increase intake offeeds and energy. Post-ruminal utilization of cell walls by using enzymes can bealso expected.Sufficient supply of crude protein and microbial proteins from feeds to smallintestine.Influence of disbalance or synchronisation of digestive processes on efficiency andhealth in animals and on environment.Decrease in energy losses, mainly by decreased creation of methane in rumen.Knowledge of nutrients digestion in individual parts of digestive tract is necessary torecognize these processes. The criterion of nutritive value in feeds for ruminants is nottotal content of crude protein but the amount of really digested crude protein in smallintestine, which depends on level of microbial proteosynthesis and crude proteindegradability in proventriculi. Out of total amount of received crude protein from feedsare 70 – 80 % de-aminated to keto acids and ammonia by activity of proteases producedby bacteria and protozoa; ammonia is then at disposal for synthesis of bacterial proteins.Level of bacterial synthesis is closely connected to the change of saccharides and it isdependent on sufficient amount of disposable energy. Increased consumption of crudeprotein at high efficiency cannot be covered only by crude protein supplementation,which increases excess of ammonia in rumen. The problem can be solved using feedswith low degradability of crude protein in proventriculi only, increasing the flow of nondegradedcrude protein from feeds directly into small intestine in this way [6].It is possible to increase the amount of microbial proteins passing into small intestine byoptimization of nitrogen and energy utilization in rumen. Synchronization of speed bywhich energy and nitrogen are released from feeds influences positively the synthesis ofmicrobial proteins.Table 1. True ileal amino acid digestibility of feeds (synthetic amino acid = 100%digestibility)Tested feeds Lysine ThreonineCystine +MethionineTryptophanWheat 84 85 90 88Barley 78 81 85 80Soybean meal 90 92 91 88Fish meal 93 92 91 89Wheat bran 72 69 84 80Lucerne meal 51 59 50 5068