Ileal and total tract digestibility of leucaena meal (Leucaena leucocephala Lam. de Wit) in growing pigs

Ileal and total tract nutrient and energy digestibility was studied in pigs fed three diets with increasing levels (0–200 g kg−1) of leucaena meal (LM). The diets contained sugar cane molasses as the major source of energy. The composition of LM on a dry basis, was: 93.9% organic matter, 42.0% crude fibre, 4.14% nitrogen, 16.95 kJ g−1 gross energy. Either at the ileal or at the total tract level, the LM significantly depressed nutrient and energy digestibility. Estimated ileal and total tract nitrogen digestibility of LM was 52.8 and 57.0% respectively indicating an almost zero disappearance of nitrogen from the large intestine. In vitro nitrogen digestibility of LM was 44.2%. Daily ileal and faecal output of both short chain fatty acids (SCFA) and ammonia showed a slight trend to be proportional to the level of LM in the diet. This indicated a rather incomplete disappearance of SCFA and ammonia in the large intestine. At first approach it can be stated that digestibility of OM and CP are not strongly impaired by the introduction of 100 g kg−1 of LM in the diet. It is suggested that methods to improve digestive utilization of nutrients contained in LM must be developed in order to avoid a deterioration of digestive efficiency in pigs fed considerable amounts of LM in the diet.