Evaluation of Leucaena leucocephala leaf meal as a protein source for growing-finishing pigs

Abstract

A study was conducted to evaluate the use of Leucaena leucocephala leaf meal (LLM) as a protein supplement for pigs. In addition, an evaluation of detoxifying LLM, by sun-drying, water-soaking, or treating with ferrous sulphate (FeS04) solution was undertaken. The research involved two experiments; a growth study and a metabolic study. In the growth study sixteen, 12 weeks old Large White x Landrace pigs (average body weight 22.9 ± 2.12 kg) were fed four experimental rations; a commercial grain-based grower /finisher ration (control); or a ration containing 20% of either sun-dried LLM, water-soaked LLM, or FeS04-treated LLM, replacing the basal diet. There was a significant (P<0.05) decrease in liveweight gain, feed intake and feed conversion efficiency in pigs fed the ration containing sun-dried LLM. Growth rate, feed intake and feed conversion efficiency were not affected by the addition of water-soaked and FeS04-treated LLM to the basal diet. Triiodothyronine (T3) and thyroxine (T4) levels in the blood plasma were not affected by the dietary treatments. However, addition of FeS04-treated LLM to the basal diet significantly (P<0.05) decreased the back fat thickness of the pigs. In the metabolic study, the digestible dry matter (DDM) and digestible CP (DCP) were measured as well as mimosine, 3-hydroxy-4-(1H) pyridone (3,4-DHP) and 2,3DHP output in the faeces and urine.Addition of water-soaked LLM to the diet significantly (P<0.05) lowered the DDM of the diet, whereas addition of FeS04-treated LLM significantly (P<0.05) reduced the DCP. Sun-drying, water-soaking and treatment of LLM with FeS04 solution, did not enhance the output of mimosine or 3,4-DHP in the urine and faeces. The results suggest that water soaking or treatment with FeS04 solution reduces the antinutritional factors (presumably including mimosine) and therefore improves the nutritional quality of LLM containing diets for pigs.