ORIGINAL RESEARCH The value of Leucaena leucocephala bark in leucaena—grass hay diets for Thai goats Brian Palmer & Raymond J. Jones & Somsak Poathong & Jeerasak Chobtang Accepted: 13 June 2010 / Published online: 20 June 2010 # Springer Science+Business Media B.V. 2010 Abstract The study assessed the value of Leucaena leucocephala bark in leucaena—grass hay diets fed to Thai goats. Thai goats in metabolism pens were fed diets containing leucaena leaf (55%) + pangola grass hay (hay, 45%); leucaena leaf (48%) + leucaena bark (9%) + hay (43%); leucaena bark (57%) + hay (43%); and hay only. Feed percentages are expressed on a dry weight basis. The digestibilities of dry matter (DM) and crude protein (CP) were measured for the four diets. Leucaena bark had lower CP concentration than the leaf (11.7 vs. 25.9), and the leucaena bark + hay diet had lower DM and CP digestibility than the other diets. The calculated bark digestibilities of DM and CP of 44.1% and 38.2%, respectively, were much lower than the values for the leucaena leaf of 62.9% and 89.1%, respectively. The lower than expected CP digestibility was attributed to higher tannin levels in the bark compared to the leaves. Despite this, the bark was well accepted by the goats and was often preferred to the hay. Stripping of the bark by goats also results in stems that dry quicker and have higher calorific value as fuel. However, if leucaena branches are fed as a sole diet, the goats may consume up to 30% of bark on a DM basis and this would reduce nutritive value and animal productivity. Keywords Leucaena leucocephala . Bark . Tannins . Goats . Digestibility Abbreviations CP Crude protein (g) CPD% Apparent crude protein digestibility CPI Crude protein intake per MW (g/MW) DCPI Digestible crude protein intake per MW (g/MW) DDMI Digestible dry matter intake per MW (g/MW) DHP 3-Hydroxy-4(1H)-pyridone DM Dry matter (g) DMD% Apparent dry matter digestibility DMI Dry matter intake per MW (g/MW) FDMO Faecal dry matter output per MW (g/MW) FNO Faecal nitrogen output per MW (g/MW) MW Metabolic weight (live weight (kg) 0.75 Introduction Smallholder farmers in the tropics often feed cut Leucaena leucocephala (leucaena) as chopped forage or as whole branches to penned goats. In Thailand, the branches may be placed on frames above the pens, allowing the goats to browse the large stems. In the process, the goats consume not only the leaf and green shoots but also strip and eat the B. Palmer (*) 2/30, Camp Street, Mundingburra, Townsville, Queensland 4812, Australia e-mail: bpcnrt@bigpond.com R. J. Jones 15, Norwich Court, Kirwan, Townsville, Queenland 4817, Australia S. Poathong Animal Research and Development Center, Cha Am, Petchaburi 76120, Thailand J. Chobtang Department of Livestock Development, Animal Nutrition Division, Ratchathewi, Bangkok 10400, Thailand Trop Anim Health Prod (2010) 42:1731–1735 DOI 10.1007/s11250-010-9628-9