DAYRIT, ARTHUR D. October 2007. Growth Performance of Completely-Confined Lambs Fed Napier Grass Supplemented With Shrub Forage Legumes (Desmodium cinerea and Desmanthus virgatus). Pampanga Agricultural College, Magalang, Pampanga. Adviser: Leopoldo F. Reyes, PhD This study aimed to evaluate the growth performance of completelyconfined St. Croix lambs fed Napier grass supplemented with shrub legumes (Desmodium cinerea and Desmanthus virgatus). The feeding trial was conducted for 120 days from February 09 to June 23, 2007 at the Small Ruminant Genetic Improvement Program (SRGIP) of Central Luzon Integrated Agricultural Research Center at Sto. Nifio, Magalang, Pampanga. Sixteen lambs where randomly distributed in a factorial experiment following the Randomized Complete Block Design with eight treatments replicated two times. Legume species (Desimodium cinerea and Desmanthus virgatus) were considered as Factor A and grass to legume ratio (100:0, 90:10, 80:20, 70:30) as Factor B. Growth performance of lambs supplemented with legumes was compared to the control (lamb fed 100% Napier grass). Average weight gain of lambs supplemented with 30% D. virgatus obtained the highest gain in weight at 4.27 kg, followed by lambs fed 30% D. cinerea with weight gain of 4.10 kg. Weight gain of lambs fed legumes at the rate of 10, 20 and 30% of the diet of either species was 82.86% higher than lambs fed the control diet (3.84 kg vs. 2.10 kg).