The influence of fibre in the diet on growth rates and the digestibility of nutrients in the greater cane rat (Thryonomys swinderianus)

The greater cane rat Thryonomys swinderianus is a coprophagous rodent in wh ich fermentation occurs in the large caecum. The extent to which a 45% incr ease in the fibre component of the diet influenced growth rates of cane rat s and the digestibility of nutrients and energy was investigated in two fee ding trials. Higher fibre levels in the diet reduced the digestibility of d ry matter, protein and fat, while animals digested fibre components (neutra l-detergent fibre, acid detergent fibre, hemicellulose and cellulose) with a comparable efficiency to those maintained on a low fibre diet. In one of the trials animals fed the high fibre diet exhibited significantly lower gr owth rates than animals fed the low fibre diet. Digestibility coefficients of the cane rats for neutral-detergent fibre and protein seem to be interme diate to high when compared to reported Values for the porcupine, guinea-pi g, degu and rabbit. It is suggested that the ability of cane rats to utilis e large quantities of fibre enable them to survive periods when only dry gr ass is available. (C) 1999 Elsevier Science Inc. All rights reserved.