Intake, digestibility and milk yield in goats fed Flemingia macrophylla with or without polyethylene glycol

High quality forage proteins for tropical goat dairy feeds are often difficult to find and many perennials contain condensed tannins (CT) that may not always benefit production. The objective of this study was to evaluate milk yield, apparent digestibility of nutrients and intake of crossbred dairy goats fed Tifton 85 (Cynodon spp. hybrid) grass replaced by the leguminous shrub flemingia (Flemingia macrophylla) with or without polyethylene glycol (PEG) to neutralize CT which were present at 105 g/kg DM. Treatments consisted of six diets containing 0%, 12.5% and 25% flemingia with or without PEG. Adding flemingia increased (P <= 0.05) dietary concentrations of CT, lignin, protein and rapidly degradable polysaccharides (A+B1). The digestibility of nutrients at 12.5% of flemingia inclusion did not differ (P > 0.05) from the legume-free diet; however, levels of 25% negatively influenced (P <= 0.05) intake of hemicellulose and dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF) and total carbohydrate digestibility, but this was neutralized when PEG was added. Histochemical tests on the leaf midrib, petiole and petiolule indicated the presence of idioblasts with phenolic compounds in trichome, collenchyma and parenchyma cells. We conclude that flemingia leaves can replace Tifton 85 grass as a supplement in low quality diets of dairy goats. (C) 2013 Elsevier B.V. All rights reserved.