Effect of dietary additives on feed efficiency and methane emissions in dairy cattle

• Grant number: 25/24704-4
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: January 01, 2026
• End date: April 30, 2026
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: Danilo Domingues Millen
• Grantee: Letícia de Mattos Machado
• Supervisor: Hilario Cuquetto Mantovani
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil
• Institution abroad: University of Wisconsin-Madison (UW-Madison), United States
• Associated to the scholarship: 24/21137-9 - Histology and cecal lesions of Nellore cattle submitted to different adaptation protocols for Intensive Finishing on Pasture (TIP)., BP.IC

Abstract

Nutritional interventions that modify the rumen microbial ecosystem and provide energy and nitrogen sources to the host have the potential to improve feed efficiency by enhancing the bioconversion of dietary substrates into microbial protein and gluconeogenic short-chain fatty acids that can be used by lactating dairy cows as a source of energy. In addition, diverting electron disposal in the rumen away from methane production is desirable to reduce the environmental impact of intensive ruminant production systems. Our proposed work aims to evaluate a range of energetic and/or protein precursors with potential to: 1) optimize rumen fermentation and microbial growth in vitro, and 2) lower enteric methane emissions in dairy cows. The in vitro screening will inform mechanistic commonalities between the tested additives and provide a basis for evaluating the inclusion of the experimental feed additives in the in vivo experiments. Changes in the rumen and fecal microbiomes will be characterized using molecular methods, including 16S rDNA sequencing and metagenomics. Findings from this project will help devise intervention methods to improve rumen function and optimize metabolic outputs, with potential benefits for dairy cow feed efficiency. (AU)