Rocha Junior et al., 2003. Rev. Bras. Zootec., 32 (): 473-479

The objective was to evaluate the equations system for determination of the TDN of six forages (corn silage, sugar cane with 1% urea, coastcrossgrass hay 1, coastcross grass hay 2, tifton grass haylage and elephant grass) and 12 concentrate feeds (corn grain ground, sorghum grain ground, corn germ, wheat bran, rice bran, babaçu meal, soybean meal, cotton meal, cotton seed, corn gluten, corn gluten meal and soybean hull) were determined using sheep as experimental animals. Forages and concentrates feed were combined in two different levels, following a completely randomized design with four repetitions for each level. The same animals were utilized to the two concentrate levels, in two consecutive periods. The diets refering to the two concentrate levels were isonitrogenous. The corn silage, sugar cane with 1% urea, coastcross grass hay 1, coastcross grass hay 2, tifton grass haylage and elephant grass presented, respectively, the following TDN values: 59.56, 60.57, 48.59, 50.24, 60.49 and 49.59%. The concentrate feeds presented the following TDN values: corn grain ground (93.75%), sorghum grain ground (82.82%), corn germ (85.30%), wheat bran (74.28%), rice bran (80.65%), babaçu meal (49.38%), soybean meal (83.24%), cotton meal (67.75%), cotton seed (88.07%), corn gluten (85.34%), corn gluten meal (75.61%) and soybean hull (68.95%). The equations system was efficient in determination of the energy value of feed, because the high correlation between those values and the digestibilities of dry matter and organic matter of all feeds evaluated.