Evaluation of the nutritive value of some selected forages in late dry and early rain seasons by white Fulani heifers in Ibadan, Nigeria

Abstract

The nutritive value of eleven tropical forages: Cynodon dactylon, Panicum maximum, Ipomea aquatica, Althernanathera dentata, Sarcolepis africana, Leucaena leucocephala, Centrosema molle, Echinochloa stagirina, Pennisetum purpureum, Setaria baratata and Panicum maximum regrowth selected by white Fulani heifers in two prominent seasons of the year in the tropics (early rain and late dry) were studied through analysis of their proximate composition, fibre fractions and in vitro digestibility. Results of the proximate analysis showed an increase in the crude protein (g/100g DM) from 7.37% in Panicum maximum to 27.39% for Leucaena leucocephala. Crude fibre value ranged between 12.87% for Leucaena leucocephala and 29.60% for Centrosema molle. Neutral detergent fibre, acid detergent fibre and acid detergent lignin was significant among the forages. A significantly highest gas volume was obtained in Ipomea aquatica and the gas production rate constant (c) was not significant in the late dry season. The estimated metabolisable energy (ME) (MJ.Kg^-1DM), organic matter digestibility (OMD %) and short chain fatty acid (SCFA) (µm) ranged from 10.15 (Setaria bartata) to 20.98 (Leucaena leucocephala), 43.65 (Sarcolepis Africana) to 53.28 (Leucaena leucocephala) and 0.31 (Athernanthera dentata) to 0.71 (Ipomea aquatica). Seasonality effect on insoluble but degradable fraction (b) was significant ranging from 11.00mL in Panicum maximum regrowth to 28.00mL in Centrosema molle. The dry matter degradability (%/200mg DM) showed that Ipomea aquatica had the highest dry matter degradability (83.50) and the lowest value was recorded for Panicum maximum (48.53). It is therefore concluded from this study that seasonality affect the nutritive value of different forages in the tropics. Therefore forages in the rain season can be preserved for use in the off season so as to stabilize ruminant production.