Assessment of chemical composition of natural pasture oversown with two Stylosanthes species for ruminant feeding

Abstract

Chemical composition of a Panicum maximum dominated natural pasture were evaluated. Two legumes (Stylosanthes guianensis cv. Cook and Stylosanthes hamata cv. Verano), two tillage methods (zero-tillage and minimal tillage) and two planting methods (broadcasting and drilling) were combined into eight (8) treatments and replicated 4 times as a 2 × 2 × 2 factorial arrangements in a randomized complete block design. The two legumes were oversown into the natural pasture. Samples of existing dominant grass (P. maximum), sown legumes, and grab samples were taken for proximate and fibre analyses, 8 months after planting which is early period of rainy season. Results revealed that crude protein (CP, 6.48-14.45%), neutral detergent fibre (NDF, 65.50-78.50%) of P. maximum, ash (8.75-15.60%), CP (8.87-16.48%), ether extract (EE, 0.75-5.00%), acid detergent lignin (ADL, 18.5-41.00%), cellulose (10.50-36.00%) and hemicellulose (16.50-33.00%) of the two legumes varied significantly (p<0.05). There were significant variations (p<0.05) in ash (9.25-15.63%), CP (11.00-17.84%), EE (1.50-5.00%) and NDF (65.5078.50%) contents of grab samples. The study concluded that CP contents were generally high above recommended minimum requirement but in grab>legumes>grass order. CP contents were better enhanced by oversowing through drilling of S. guianensis with either tillage methods or broadcast of S. hamata notwithstanding zero tillage. The forages would be poorly digested owing to high fibre contents amassed over long growing time; hence periodic cutting or grazing is encouraged.