Experimental reproduction of phytobezoars.

In a series of in virtro experiments (n = 64) using the mature flowers or seeds and pappus hairs of Karoo bushes Chrysocoma ciliata, Dimorphotheca cuneata, Eriocephalus ericoides, Gazania krebsiana and Gnidia polycephala, small phytobezoars were formed from material of E. ericoides, G. krebsiana and G. polycephala either alone or in combinations. The ratio of fibre to liquid used was found to be optimal around 1: 7 and milling of material enhanced bezoar formation. Time and pH did not appear to significantly affect the formation of bezoars. Other factors were either standardised or not studied. In a small in vivo trial, 4 groups of one sheep and one goat each were fed 10% of either C. ciliata, E. ericoides, G. polycephala seeds and pappus hairs, or a mixture of all 3, added to a basal diet of milled lucerne fed for up to 31 d. Small phytobezoars were formed in the goats but not the sheep receiving C. ciliata, and G. polycephala material. It was concluded that phytobezoars could form in goats or sheep eating large quantities of mature flowers or seeds of several Karoo bushes.