Rumen degradability of some feed legume seeds

Abstract

The aim of this work was to determine the effective degradability (ED) of CP for different feed legume seeds and the possible relationship with their physical and chemical characteristics. The ED was measured using nylon bags and rumen outflow rate techniques on three rumen cannulated wethers fed at 40 g DM·kg-0.75, with a 2:1 (on DM basis) hay to concentrate diet. Nine seed samples of the following legume species were tested: lupin (Lupinus albus L., cultivar multolupa), dwarf chickling (Lathyrus cicera L.), common chickling (Lathyrus sativus L.), common vetch (Vicia sativa L.) hairy vetch (Vicia villosa Roth.), bitter vetch (Vicia ervilia L.), monantha vetch (Vicia monantha Desf.) and field bean (Vicia faba L., variety minor Beck). Two different cultivars of this last species were studied: P69 (sample 1) and Jasper (sample 2). Estimates of ED of dry matter (DM) and crude protein (CP) were obtained for rumen outflow rates of 5.04 ± 0.31%·h -1, determined for the diet concentrate. The variation of the ED of DM was moderate (from 58.8 to 69.2%) and correlated with the proportion of nitrogen linked to the acid detergent fibre (r = -0.847). Values of ED of CP of these seeds (in the above indicated order) were 79.4, 71.3, 80.7, 75.3, 75.4, 69.3, 76.6, 77.0, and 73.8%. Significant correlations between the ED of CP and the chemical composition or CP buffer solubility were not found.