In vitro gas production, in vivo nutrient digestibilities, and metabolisable energy concentrations for sheep of fresh and conserved pangola grass

Abstract

In vitro gas production, nutrient digestibilities and metabolisable energy (ME) values of fresh and conserved pangola grass (Digitaria eriantha Steud., synonym D. decumbens) were studied in 16 cross-bred (Thai native×Merino) sheep. The study was designed as a completely randomized design with Napier grass (Pennisetum purpureum) as a control and pangola grass in fresh, hay and silage forms with the same cutting age (45 days growth) as treatments. Chemical composition of forages and faeces was determined and used to estimate nutrient digestibility. In vitro gas production was recorded at 3, 6, 8, 12, 24, 48, 72, 84 and 96h of incubation and used to estimate the kinetics of gas production. Chemical composition was relatively constant across treatments. Likely due to the addition of 5% sugarcane molasses before ensiling, pangola grass silage had higher (P<0.05) nutrient digestibilities and ME concentrations than the other forages when estimated from in vivo digestibility and in vitro gas production. Cumulative gas production at 12, 24, 48 and 96h of incubation was highest (P<0.05) in pangola silage followed by fresh pangola, pangola hay and Napier grass, in that order. In conclusion, pangola grass in fresh or conserved forms has a high potential to deliver energy and protein through forage and can be recommended as a nutrient source for small ruminants.