In vitro gas production and in vivo nutrient digestibility and growth performance of Thai indigenous cattle fed fresh and conserved pangola grass

Abstract

Fresh and conserved pangola grass (Digitaria eriantha Steud., synonym D. decumbens) were compared in terms of in vitro gas production and in vivo nutrient digestibility, metabolisable energy (ME) concentration and average daily gain (ADG) of Thai indigenous cattle. The study was designed as a completely randomised design with Ruzi grass (Brachiaria ruziziensis) as a control and pangola grass in fresh, hay and silage forms at the same age at harvest (45 days regrowth) as treatments. As intended, the dry matter (DM) intake of forages supplemented with concentrate and a protein block was not different (p > .05) among treatments. All forms of pangola ranked higher in crude protein and ME concentrations than Ruzi grass. Pangola silage, to which 5% sugarcane molasses was added at ensiling to minimise the risk of bad fermentation, produced more gas in vitro after 96 hours of incubation and had greater (p < .05) in vivo DM, organic matter and crude protein apparent digestibility and ME concentrations and resulted in higher ADG of cattle. In conclusion, the form of pangola grass had a direct effect on digestibility, ME and ADG of Thai indigenous cattle. Pangola silage ranked higher than its fresh and hay forms as well as Ruzi grass which was the control. Pangola grass is a feasible alternative as forage source for cattle in tropical countries and can be recommended as a grass species for feeding especially during dry season.

Keywords

• Forage conservation
• in vitro gas production
• metabolisable energy
• nutrient digestibility
• tropical grass