Effect of fibrolytic enzymes on digestion, ruminal fermentation, microbial population, and nutrient flow in a dual-flow continuous culture system

• Grant number: 18/10328-7
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: November 01, 2018
• End date: April 30, 2019
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: Ives Cláudio da Silva Bueno
• Grantee: Richard Roberto Lobo
• Supervisor: Antonio Pinheiro Faciola
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil
• Institution abroad: University of Florida, Gainesville (UF), United States
• Associated to the scholarship: 17/25319-0 - INCLUSION OF YERBA MATE EXTRACT IN DIETS TERMINATION FOR SHEEP: EFFECTS ON METHANOGENESIS AND MEAT QUALITY, BP.MS

Abstract

The objective of this study will be the evaluation of inclusion different fibrolytic enzymes and its effects on fermentation and degradability of diets in the dual-flow continuous culture system. The experiment will be carried out in the Faciola's Lab at the Department of Animal Science, University of Florida, with eight fermenters (dual-flow continuous culture system); each fermenter unit will be randomly assigned to receive each diet once over the 4 periods in a replicate 4x4 Latin square design. Each 10-day period will comprise 7-day diet adaptation period followed by a 3-day sampling period. Experimental treatments will be a control diet and other 3 diets with different types of fibrolytic enzyme. The Faciola Lab team will define the dosis and types of fibrolytic enzyme. Each fermenter will be manually fed a total of 72 g DM/d equally divided in two meals per day. Rumen fluid will be collected approximately 2 h after morning feeding from two ruminally cannulated dairy cows. Rumen fluid (1,250 mL) will be then poured into each of the fermentation jars until it cleared the overflow spout. During the last 3 days of each period, liquid and solid effluents from each fermenter will be combined and homogenized. Then, samples will be stored for the N-NH3 and shot chain fatty acids analysis. At the end of each period, digesta effluent from the three sampling days will be composited by fermenter and freeze, for measurement of dry matter, ash, crude protein, ether extract, neutral detergent fiber, and acid detergent fiber, and for the estimation of degradability. At the same time to the sample collection for evaluation of the fermentation (day 8, 9, and 10), at 2, 6, and 10 h after morning feeding. At the same time points, solid particles will collected from solid effluent containers of each fermenter. Liquid and solid samples will stored at -80°C for further DNA extraction. For the DNA extraction will used the Phenol-chloroform method. The 16S and 18S rRNA gene will amplified for the bacterial, archaea, and protozoa DNA. All statistical procedures will be carried out using SAS 9.2 for windows, with ± = 0.05.