Effect of Leucaena leucocephala leaf meal treated with acetic acid or sodium hydroxide on apparent digestibility and nitrogen retention in pig diets

Forty male pigs (43.4±6.2 kg of liveweight) housed in metabolism crates were used to evaluate the effect of Leucaena leucocephala leaf meal (LLM) treated with acetic acid (AA) or sodium hydroxide (NaOH) in pig diets, on coefficient of total tract apparent digestibility (CTTAD) of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF) and nitrogen balance (NB). The experimental diets included 200 g LLM kg−1 which had been treated with four levels (0, 30, 60 and 90 g kg−1 DM) of AA or NaOH, respectively as chemical treatments. The experiment was conducted in two periods: 7 days for adaptation, and 7 days for total urine and faeces collection. There were no differences (P>0.05) between treatments (AA and NaOH) on CTTAD of DM, OM and CP. However, CTTAD of NDF was higher (P<0.05) in pigs fed diets with LLM treated with AA (0.49) than in pigs fed diets with LLM treated with NaOH (0.44). There were no differences (P>0.05) on apparent digestibility between levels of treatments (0, 30, 60 and 90 g kg−1). Nitrogen retained was higher (P<0.05) in pigs fed diets that included LLM treated with level 30 g kg−1 of AA or NaOH (11.2 g per day) in comparison to pigs fed diets with LLM treated with 0, 60 and 90 g kg−1 (4.6, 7.3 and 6.7 g per day, respectively) as seen from the quadratic response. The results obtained in the current work suggest that treating LLM with 30 g kg−1 of AA or NaOH increased nitrogen retention in growing pigs.