Reticular, omasal and abomasal collection methodologies for evaluation of the ruminal biohydrogenation in dairy cows

• Grant number: 12/08955-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): August 01, 2012
• Effective date (End): July 31, 2013
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: José Esler de Freitas Júnior
• Grantee: Marjorye Kaori Kametani
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The knowledge of the local changes in nutrients digestion may explain differences in performance and digestive metabolism of nutrients in ruminants. Fistulas allow access to the lumen of the digestive tract for the collection of food being digested and diffusion of nutrients that are indicators to monitor chemical aspects (hydrolysis and synthesis) and physical (flow) of digestion. Traditionally, the main method used to estimate the luminal flow consists in the fistula of the "T" type with duodenal sampling. The methods to measure the flow of nutrients within the digestive tract, until recently were limited to the utilization of animals fistulated in the omasum, abomasum or duodenum. Little research was developed to measure the flow of digesta without the fistulation post-ruminal involving the fat metabolism. . It is because, the digestion process of lipids in ruminants can be considered one of the more complex, and it is summarized by two main stages, lipolysis and biohydrogenation of unsaturated fatty acids. In the second may occur variances depending of the site of collection. However, the ruminal kinetics of the digestion process of lipids, summarized in these two processes, has been studied for several years. The biohydrogenation may be considered the process of self-defense of rumen microorganisms, which converts unsaturated fatty acids (C18:2 and C18:3) into saturated fatty acids, less toxic to the ruminal population microbial. Furthermore, that process decreases the intestinal flow of polyunsaturated fatty acids to the duodenum and contributes to the accumulation of isomers of conjugated linoleic acids, cis and trans, of ruminants derived products. Some researchers have wanted appropriate alternatives for estimating the ruminal flow of fatty acids and proposed a method of reticular and omasal sampling for estimating the fatty acids flow of the food being digested in the rumen. More recent studies have valued a method of reticular sampling instead of omasal sampling, whereas for collection of food being digested in omasum is necessary for the utilization of more sophisticated equipment. The present experiment will be conducted with aim of evaluating methodologies of reticular, omasal, and abomasal collection for the evaluation of ruminal biohydrogenation.(AU)