Chemical composition and digestibility of six legumes from the state of Morelos, Mexico

Abstract

Objective: To evaluate the chemical composition and in vitro digestibility of six forage legumes from Morelos, Mexico: Acacia angustissima, Dalea spp, Desmodium spp, Leucaena leucocephala, Phaseolus vulgaris and Tephrosia vicioides.

Design/methodology/approach: There is little information about the nutritional value of these legumes, so crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), crude lignin (CL), cellulose (Cel), hemicellulose (Hcel), cellular content (CC) and in vitro dry matter digestibility (IVDMD) were determined. The design was completely randomized with three replicates. Variables were pairwise correlated and legume means were compared using the Tukey test (P<0.05).

Results: Dalea spp contained higher CP (17.7%), followed by Acacia angustissima (15.9%) and Leucaena leucocephala (14.1%). Acacia angustissima (73.2%), Dalea spp (74.9%) and Phaseolus vulgaris (77.5%) showed the highest IVDMD values. Leucaena leucocephala, Tephrosia vicioides and Desmodium spp produced the lowest values of CP (14.1, 11.8 and 12.3%, respectively) and IVDMD (70.4, 70.2 and 64.9%, respectively). Desmodium spp, showed high values of NDF (59.2%), ADF (41.4%), CL (17.5%), Cel (29.7%) and Hcel (17.8%) (P<0.05).

The IVDMD showed positive correlations with CC, and negative correlations with NDF, CL and Hcel (P<0.05).

Limitations/implications: Desmodium spp showed high CL content, and low CP and IVDMD values (P<0.05), therefore, it is recommended supplement this legume, when used in animal feeding.

Findings/conclusions: Because Dalea spp presented low lignin content and high protein and digestibility values, it is possible to use this legume for ruminant feeding.