In a performance trial, 50 intact Rambouillet )Dorper male lambs (1992.8 kg), were randomly assigned to experimental diets containing 0, 10, 20, 30 or 40%, Opuntia leucotrichia (O. leucotrichia; dry matter basis). At day 91 animals were slaughtered for carcass and meat quality evaluation. In trial two, five ruminal cannulated Rambouillet male rams were used in a digestion study. Dry matter intake, average daily gain and feed efficiency of lambs decreased (P B0.05) generally with increasing levels of O. leucotrichia. Carcass dressing was increasing as O. leucotrichia was augmented. Water intake decreased as consumption of O. leucotrichia increased. Crude protein was digested higher (P B0.05) in lambs fed 40% diet than other lambs. Ruminal pH and ammonia-N were not significantly different among treatments. Inclusion of O. leucotrichia on feedlot lamb diets is a good option for production systems if this resource is available.