Recovery ratio of internal markers to estimate the fecal excretion in horses - Pombo, Gabriela do Vale; Brandi, Roberta Ariboni; Moreira, Camilla Garcia; Menezes, Madalena Lima; Cunha, Tiago Sartori da; Souza, Aline Duarte de; Mota, Thais Pagotti; Bueno, Ives Cláudio da Silva (Annual Meeting of Brazilian Society of Animal Science, 2013)