In vitro evaluation of additives on dry matter degradability, methane emission, gases production and the concentrations of ammonia and volatile fatty acids

• Grant number: 18/24400-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2019
• End date: January 31, 2020
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: Júlio Cesar de Carvalho Balieiro
• Grantee: Amanda Heloísa Dicilio de Alcântara
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The cell wall digestibility is the main limiting factor of the nutritional value of forage. Thus, the use of additives which can promote the digestibility of the fiber is very important for ruminants. The aim of this research is to evaluate the effect of supplementation with live cultures of the fungus Aspergillus oryzae and fibrinolytic enzyme on gases production, methane emission and fiber digestibility of different roughage sources through a gas production and in vitro degradability assay. For that, two roughage sources will be used: corn silage and cane silage with high NDF digestibility (IACSP93-3046). The roughage will be subjected to the following treatments: doses of the fungi A. oryzae (FO - without the addition of AO; F1 - 1g of AO; F3 - 3g of AO and F5 - 5g of AO), doses of the fibrinolytic enzyme (Fibrozyme - Alltech; E0 - without the addition of enzyme; E8 - 8g of enzyme; E16 - 16g of enzyme; E24 - 24g of enzyme), and combination of both, totaling 32 treatments. All treatments will be performed in duplicates. Two in vitro fermentative kinetics assay will be performed: short (24hrs) and long (96hrs), for measurement of potential gas production, methane production, short-chain fatty acids, ammoniacal nitrogen and digestibility of DM and NDF. The experimental design will be completely randomized, with a factorial arrangement of treatments (4x4x2), with four levels of fungi (0, 1, 3 and 5g), four levels of fibrinolytic enzyme (0, 8, 16 and 24g) and two levels of roughage (corn and sugarcane silage), totaling 32 treatments. Data will be analyzed using MIXED procedure of SAS software (version 9.4). The degrees of freedom and tests will be adjusted using the Kenward-Roger. Significance will be considered at P > 0.05.