When leafy, carpet grass is fairly palatable to ruminants but palatability declines as the stands flower (FAO, 2012). Reported in vivo OM digestibility of carpet grass hay ranged between 43 and 55% (Lloyd et al., 1992; Cohen, 1974).
Most ruminant trials with Axonopus fissifolius have been carried out in Australia.
Sub-tropical pastures containing mostly Axonopus fissifolius can be grazed throughout the grazing season by beef cattle, with or without protein supplementation (Hennessy et al., 1998; Hennessy, 1986; Martin, 1975). Hereford heifers grazing carpet grass-based native tropical pastures of low quality (protein 5% DM, DM digestibility 50%) gained more live weight and had a higher pregnancy rate when supplemented with molasses or molasses-cottonseed meal than those without supplementation (Hennessy, 1986). Early experiments reported lower animal performance on carpet grass pastures than on Paspalum notatum, coastal Bermuda or Digitaria eriantha pastures. In grazing cattle, live-weight gain was found to be low (70-170 kg/ha/year), with weight loss often occurring at the end of the season when the cattle were not fed a supplement. Gain can be greatly increased up to 100-700 kg/ha/year by mixing carpet grass with white clover (Trifolium repens) or Lespedeza cuneata (Martin, 1975). In Angus steers fed mature carpet grass hay in pens, DM intake reached 17.2 g/kg LW/day but digestible DM intake was only 7.6 g/kg LW/d, resulting in a daily weight loss of 0.54 kg. Supplementation with molasses (500 g/d) increased DM intake by 30%, resulting in less weight loss (0.12 kg/d). Additional supply of 60 or 120 g/d of urea had no effect on DM digestibility, DM intake and live-weight loss (Cohen, 1974).
Adult Peppin Merino sheep fed on low quality Axonopus fissifolius hay (protein 5.7% DM, OM digestibility 52%) had a DM intake of 12.3 g/kg LW/day. Increasing the amount of oats in the diet from 20 to 50% (DM basis) reduced NDF and ADF digestibilities, but increased DM or OM digestibilities (Lloyd et al., 1992).