Evaluation of different protein sources associated or not with tannin in intensive pasture finishing (TIP) of Nellore cattle

• Grant number: 25/15816-3
• Support Opportunities: Scholarships in Brazil - Master
• Start date: January 01, 2026
• End date: February 28, 2027
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Production
• Principal Investigator: Ricardo Andrade Reis
• Grantee: Isadora Alves Dornellas
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil
• Associated research grant: 22/15974-0 - Strategic grazing management and supplementation towards sustainable intensification at tropical pasture-based beef cattle production systems, AP.TEM

Abstract

Sustainable intensification has become a growing alternative in beef cattle farming globally in recent years, as this is one of the main sources of animal protein. In this context, intensive pasture-fed finishing (IPT) emerges as an efficient alternative, characterized by the provision of a high-level pasture supplement (1.6 to 2.0% BW) with balanced levels of protein, energy, and minerals during the fattening phase. This strategy aims to increase production levels, individual weight gain, carcass yield, and productivity per area without requiring significant investments in fattening facilities. Combined with supplementation, the inclusion of additives such as condensed tannins (TC) in animal diets increases microbial protein synthesis by reducing ruminal degradation of soluble protein fractions due to the formation of complexes (protein-tannin), fostering greater microbial growth. It also increases nitrogen use efficiency (NUE) and reduces enteric methane (CH4) emissions from beef cattle. This study aims to evaluate the effects of two sources of protein supplements containing or not condensed tannin (TC) on the intensive pasture finishing (IPT) of Nellore young bulls, kept on pastures of Xaraés (Uroclhoa brizantha) cultivar grass, during the dry period. To evaluate metabolism (dry matter and nutrient intake and digestibility, ruminal parameters (pH, N-NH3, and short-chain fatty acids (SCFA)), nitrogen utilization efficiency, microbial protein synthesis, and ruminal microbiology), eight rumen-cannulated animals with an average body weight (BW) of 289 kg will be used. They will be distributed in a 4x4 double Latin square design in a 2x2 factorial arrangement (Factor A: protein sources (peanut meal (PM) and distillers' dried grains with solubles (DDGS); and Factor B: with and without tannin). Concomitant with the study described above, animal performance and enteric methane emissions will be evaluated. 48 tester animals will be distributed in a completely randomized design with initial body weight used as a covariate and in a factorial arrangement as described above. The evaluated treatments will be supplied at a level of 1.8% of body weight (BW) and will consist of: T1 - peanut meal; T2 - peanut meal + TC; T3 - DDGS; T4 - DDGS + TC. The means will be compared by Tukey's test (p < 0.05), using the Proc Mixed of SAS (2008). (AU)