The use of additives, such as additional sources of fat, it has been common practice in the feeding of ruminants, especially for allowing the improvement of the status of energy production and performance of animals. As an alternative antibiotic ionophores used since the 1970, and today prohibited in the European Union, was recently proposed the use of chitosan to modulate ruminal fermentation and digestion, with promising results. Chitosan (polymer-N-acetyl-D-glucosamine) is a biodegradable polymer, non-toxic, derived of deacetylation of chitin, which is, in turn, the most abundant in nature biopolymer after cellulose, the major component being the exoskeleton of crustaceans and insects. Because it is a byproduct of the fishing industry, chitosan has a low cost. Both the supplemental fat sources, as the use of additives such as ionophores can influence ruminal lipid. The biohydrogenation is an important step in ruminal metabolism of fatty acids and can be considered self-defense process of rumen microorganisms, which convert unsaturated fatty acids into saturated fatty acids, less toxic to the rumen microbial population. Additionally, this process reduces the intestinal flow of polyunsaturated fatty acids to the duodenum which can effect nutraceutical and / or moderate metabolism and physiology of the animal. The hypothesis to be evaluated in this experiment is that the use of chitosan associated with a fat source, using soybean whole and raw, alters ruminal fermentation and lipid biohydrogenation without interfering negatively on consumption and digestibility of dry matter and nutrients, improving the yield and composition milk. Thus, the objective was to evaluate the effects of association of chitosan with soybean whole and raw in the diets of dairy cows on intake and total apparent digestibility of dry matter and nutrients, fermentation and rumen microbial protein synthesis, production and milk composition concentrations of blood parameters, fatty acid profile in milk fat, and energy balances and nitrogen.
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