Evaluation of tropical top feed species for their nutritional properties, in vitro rumen digestibility, gas production potential and polyphenolic profile

The present study was planned to screen nutritional properties of eight different species of top feeds viz., Acacia nilotica, Azadirachta indica, Bambusa vulgaris, Ficus benghalensis, Leucaena leucocephala, Pithecellobium dulce, Senegalia catechu and Terminalia arjuna used in southern Gujarat, India. Top feeds were assessed for their chemical composition, in vitro digestibility, gas production potential and polyphenolic fraction using rumen liquor of Surti buffalo. To check resemblance, two conventional fodders Sorghum vulgare and Medicago sativa were also assessed. Crude protein (CP) content was in the range of 10.28 (Acacia nilotica) to 21.71% (Pithecellobium dulce). The NDF content varied from 35.57% (Acacia nilotica) to 64.47% (Bambusa vulgaris). Acacia nilotica had the highest total phenolic (12.60%) content, whereas Azadirachta indica had higher condensed tannin (CT) content (8.60%). In vitro dry matter digestibility (IVDMD) and in vitro organic matter digestibility (IVOMD) of top feeds ranged from 75.41 to 86.71% and 50.09 to 72.67%, respectively. The in vitro gas production (IVGP) was high (P>0.05) in Azadirachta indica (44.00 ml). Results revealed that all proximate components, fiber fractions, mineral content, total phenols and their fractions in top feeds were found comparable to or better than conventional fodders. Major parameters of in vitro digestibility were also resemblance and more comparable to conventional fodders. However, Acacia nilotica, Azadirachta indica, and Pithecellobium dulce were found best suitable amongst top feeds by considering their chemical composition, phenolic contents and in vitro rumen evaluation.