REGULAR ARTICLES Evaluation of local energy sources in milk production in a tropical silvopastoral system with Erythrina poeppigiana Guillermo Jiménez-Ferrer 1 & Germán Mendoza-Martínez 2 & Lorena Soto-Pinto 1 & Armando Alayón-Gamboa 3 Received: 28 November 2014 /Accepted: 25 March 2015 # Springer Science+Business Media Dordrecht 2015 Abstract An experiment was carried out to determine the effect of four local energy sources (sorghum grain, green ba- nana, polished rice, and sugarcane molasses) fed to dairy cows on intake, milk production and composition, and economic viability in a silvopastoral system in Costa Rica (Turrialba). Twelve grazing cows (Jersey × Central American Milking Creole), with a mean live weight of 332 kg (SD 34), were supplemented with 0.5 kg of dry matter (DM)/100 kg/LW of Erythrina porppigiana fresh foliage daily. Experimental de- sign was a replicated change—over 4×4 Latin Square. The pasture composition was 11 and 17 % of star grass (Cynodon niemfuensis), 32 and 28 % of ruzzi grass ( Brachiaria rusisiensis), and 45 and 42 % of natural grasses (Axonopus compresus and Paspalum conjugatum) at initial and final times of the essay, respectively. The grass allowance was 30.14 DM/cow/day. Significant differences were found among treatments for variable milk fat content (P <0.05). Sorghum presented the highest (41.2 g/kg milk) content of milk fat, followed by green banana (39.2 g/kg milk), polished rice (38.3 g/kg milk) and molasses (38.1 g/kg milk). Non- significant differences (P >0.05) resulted for total milk production (sorghum 9.0 kg/cow/day; green banana 8.9 kg/ cow/day; polished rice 8.8 kg/cow/day; molasses 8.6 kg/cow/ day) and fat-corrected milk (FCM). The financial analysis showed that all treatments were economically viable; howev- er, supplementation with green bananas and molasses were the most favorable due to the low costs incurred. Keywords Fodder tree . Agroforestry . Dairy cows . Central America Introduction In Latin America, food energy for livestock is provided main- ly by pastures which are generally unable to meet nutrient requirements for milk and meat production. The use of agro- forestry livestock practices—particularly silvopastoral sys- tems—is regarded as an option to obtain highly nutritive fod- der as well as environmental services derived from growing trees (Murgeitio, 2011). The importance of using fodder trees as supplements, either as cut-and-carry forage or directly in grazing systems, lies mainly in their potential as a protein supplement. Various trees and shrubs native to Mesoamerica (i.e., Erythrina, Gliricidia, Leucaena, Guazuma, Prosopis, etc.) contain high crude protein in their leaves and have shown acceptable biomass production (Ibrahim et al ., 2005). However, for optimal use of tropical grasses and foliage from fodder trees, cattle require additional energy sources (Lopez et al., 2000). Although local supplements appear to be a stra- tegic alternative, animal feed concentrates are often costly and in limited supply. The objective of this study was to evaluate the bio-economic effects of four different energy sources pro- vided by local resources: green banana, polished rice, grain sorghum, and sugar cane molasses on milk production and * Guillermo Jiménez-Ferrer gjimenez@ecosur.mx 1 El Colegio de la Frontera Sur (ECOSUR), Ganadería y Ambiente, Carretera Panamericana y Periférico Sur s/n, Barrio María Auxiliadora, 29290 San Cristóbal de Las Casas, Chiapas, Mexico 2 Departamento de Producción Agrícola y Animal, Universidad Autónoma Metropolitana-Xochimilco, Coyoacán, Distrito Federal, Mexico 3 El Colegio de la Frontera Sur (ECOSUR), Unidad Campeche, Camp, Mexico Trop Anim Health Prod DOI 10.1007/s11250-015-0806-7