The influence of roughage intake on the occurrence of oral disturbances in captive giraffids

Feeding behaviour of giraffe and okapi in captivity can differ significantly from the state in the wild. Duration and complexity of feeding and ruminating behaviour, and total amount of food ingested, are o�en reduced, while the energy content of the diet is increased compared to the wild. As known from domestic ca�le in intensive keeping systems, oral disturbances like tongue-playing or licking of objects are reported to occur in captive giraffe and okapi. Oral disturbances are considered to be related to an intensive feeding system, e. g. characterised by a low intake of (physically) structured feeds like hay or fresh forage. We review evidence for this relation in domestic ca�le and in giraffids in zoos, and add some own data on 6 giraffes and 3 okapis, which suggest an increasing influence of a high unstructured/structured feed ratio on oral disturbances. The causal and functional factors responsible for oral disturbances are understood only partly to date. It is unclear whether deprivation of feeding or of ruminating behaviour is more important, whether deprivation of behaviour itself or deviations of the normal physiology of the digestive process are responsible for a relation of oral disturbances with low roughage intake, and whether they can be interpreted as adaptive behaviour. Independent of a detailed explanation for the occurrence of oral disturbances, a higher roughage intake seems to reduce the occurrence of this behaviour. Suggestions are made as to which measures may be taken to achieve an adequate roughage intake in selective ruminants, and which kinds of roughage can be regarded as adequate for them. Further research is needed to be able to judge the suitability of different kinds of roughage for giraffe and okapi.