Hellbrugge, Christopher, et al. “Steers Performance Grazing Ryegrass (Lolium Multiflorum) With or Without Energetic Supplementation”. Semina: Ciências Agrárias, vol. 29, no. 3, Sept. 2008, pp. 723-30, doi:10.5433/1679-0359.2008v29n3p723.