Effects of substitution of dried distillers grains with soybean meal on energy metabolism, nutrient flow and digestibility, and methane emissions of beef cattle

• Grant number: 25/11095-0
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: December 01, 2025
• End date: March 31, 2026
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: Murillo Ceola Stefano Pereira
• Grantee: Júlia Goia Ferreira
• Supervisor: Ana Clara Baiao Menezes
• Host Institution: Faculdade de Ciências Agrárias e Tecnológicas. Universidade Estadual Paulista (UNESP). Campus de Dracena. Dracena , SP, Brazil
• Institution abroad: South Dakota State University, United States
• Associated to the scholarship: 24/22252-6 - Effect of different roughage and physically effective neutral detergent fiber inclusion on ruminal pool sizes and neutral detergent fiber turnover rate in feedlot Nellore cattle, BP.IC

Abstract

This study will investigate the effects of replacing dried distillers grains (DDGS) with soybean meal on energy metabolism, nutrient flow and digestibility, and methane emissions in beef cattle. Four rumen-, duodenum-, and ileum-cannulated Red Angus steers will be assigned to a 4×4 Latin square design. The experimental diets will include: 1) A control diet with DDGS (15% DM); 2) A diet replacing 50% of the DDGS with soybean meal; 3) A diet replacing 75% of the DDGS with soybean meal; 4) A diet fully replacing the DDGS with soybean meal. Each experimental period will last 18 days, consisting of 7 days of diet adaptation and 11 days of sample collection. To evaluate ruminal degradation of organic matter and protein, in situ incubations will be conducted. Diet samples will be weighed into nylon bags and incubated directly in the rumen of the corresponding steer assigned to each treatment, for 0, 2, 4, 8, 16, 24, 48, and 72 hours. In addition, to determine total digestibility, steers will be housed in metabolic crates, with feed intake, refusals, and total feces and urine collected. Nutrient flow will be assessed using an indigestible marker (chromic oxide) dosed through the rumen cannula, and duodenal and ileal digesta samples will be collected at regular intervals. On the final day of each experimental period, steers will be placed in respirometry headboxes to measure greenhouse gas emissions (O2, CO2, and CH4) using indirect calorimetry. Data will be analyzed using a mixed model in SAS, with steer and period as random effects and treatment as a fixed effect.