Energy supplementation and the use of condensed tannins as strategies for beef cattle intensification

Author(s)

Andressa Scholz Berça

• Document type: Doctoral Thesis
• Press: Jaboticabal. 2023-04-18.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal
• Defense date: 2023-03-03
• Advisor: Ricardo Andrade Reis

Abstract

Energy supplementation with highly fermentable carbohydrates can be a strategy to maximize the efficiency of nitrogen use (ENU) from high-nutritional value forages. The study aimed to investigate the independent or associated effects of two diurnal feeding times (0900 or 1700 h) with two sources of energy supplementation (corn or citrus pulp) in the growing of F1 Angus x Nellore young bulls on palisade grass pastures and their implications on the forage chemical composition, nutrient intake and digestibility, ENU, microbial protein synthesis (MCP), animal performance and gain per area. The treatments consisted of energy supplementation at 0.3% BW with corn or citrus pulp fed at 0900 or 1700 h. Supplementation at 0.3% of BW with corn or citrus pulp at 0900 h or 1700 h can reach up to 1.06 kg/d of young bulls reared on palisade grass pastures fertilized with 180 kg nitrogen/ha/year and managed at 25 cm of height. There were no effects on MCP or its efficiency. The citrus pulp can be used as an alternative energy source to corn because it has the same potential for animal performance, ENU and MCP in tropical pastures with a high proportion of soluble protein and structural and non-fibrous carbohydrates with high dry matter digestibility. In the context of beef cattle intensification, condensed tannins (CT) have been widely used in ruminant nutrition, since it promotes better use of dietary protein and reduce enteric methane (CH4) emissions by altering rumen fermentation kinetics. The study aimed to develop regression equations based on the significant components and their interactions to target a specific ruminal CH4 mitigation when correctly associating CT inclusion level and diet composition. Across many experiments, increasing the level of dietary CT led to a decrease in ruminal CH4 concentrations for in vitro and in vivo fermentation conditions. Our meta-analysis identified diet components that significantly affect enteric CH4 emissions by cattle and developed a prediction model based on these components, including organic matter, crude protein (CP), neutral detergent fiber and ether extract. The in vivo CH4 method showed that an interaction between CT and CP diet content affects CH4 emissions. (AU)

• FAPESP's process: 19/25997-4 - Effect of energy supplementation time and sources to optimize F1 Angus-Nellore growing
• Grantee: Andressa Scholz Berça
• Support Opportunities: Scholarships in Brazil - Doctorate