Effect of inclusion levels of legumes in Marandu grass forage on ruminal microbiota and fermentation and gas production

• Grant number: 24/19604-8
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2025
• End date: August 31, 2027
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Pastures and Forage Crops
• Principal Investigator: Luciana Gerdes
• Grantee: Luciana Gerdes
• Host Institution: Instituto de Zootecnia. Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Nova Odessa , SP, Brazil
• Associated researchers: Adibe Luiz Abdalla ; Cristina Maria Pacheco Barbosa ; Flavia Maria de Andrade Gimenes ; Gabriela Aferri ; Paulo de Mello Tavares Lima ; Theyson Duarte Maranhão ; Waldssimiler Teixeira de Mattos

Abstract

The objective of this work will be to evaluate the parameters of fermentation and ruminal microbiota and gas production in forage of Marandu grass Brachiaria brizantha Stapf. (Syn Urochloa brizantha) cv. Marandu and legumes Macrotyloma (Macrotyloma axillare), Calopo (Calopogonium mucunoides) and Perennial soybean (Neonotonia withtii). The experiment will be conducted at the Instituto de Zootecnia, Nova Odessa for two years (January 2025 to December 2026) and forage samples will be collected during the Rainy (February 2025) and Dry (July 2025) periods. The ten treatments will be: treatment 1 T1: exclusive B.brizantha forage, T2 to T4: inclusion levels of M. axillare forage in the samples of 25, 50 and 75%, respectively and T5 to T7: inclusion of C. mucunoides and T8 to T10: inclusion of N. withtii in the same proportions. The design will be randomized with three replicates of area in two evaluation periods. The forage samples will be obtained by grazing simulation and after collection the forages will be weighed, dried in a forced circulation oven at 40ºC until constant weight and ground in a mill with 1 mm. The dry material (DM) and the ground will be weighed and the compositions made with physical mixture in the proportions indicated in the treatments, totaling 39 samples per period and 78 samples. After this stage, analyses of nutritional value will be performed (crude protein - CP, in vitro digestibility of DM, neutral detergent fiber - NDF, acid detergent fiber - ADF and lignin), total tannins, condensed tannins, total in vitro gas production and in vitro methane production and through the continuous ruminal fermentation technique, isotopic ratio of undegraded OM and methane, degradability of organic matter and NDF, ammoniacal nitrogen and short-chain fatty acids, modeling of fermentation kinetics, total gas and methane production (CH¿), fermentation parameters, and composition of the ruminal microbiota and quantification of specific microorganisms of the ruminal microbiota through real-time quantitative PCR (qPCR). It is expected to evaluate the effect of the inclusion of the legumes Macrotiloma, Calopogonium and perennial soybean in Marandu grass pastures on the nutritional value, fermentation parameters and ruminal microbiota, and gas production, aiming to estimate the potential as food and methane mitigation and providing greater sustainability to the production system. (AU)