Nascimento, R.J.T. et al. 2020. Residue of propolis extract in bovine diets with increasing levels of protein on rumen fermentation. Pesquisa Agropecuaria Brasileira. 55, X (Nov. 2020), e01572. DOI:https://doi.org/10.1590/S1678-3921.pab2020.v55.26803.