A pig diet, processed in three different ways, was evaluated in an ileal digestibility trial. The complete diet contained mainly pea, tapioca and soybean meal and was processed by steam-pelleting (SP), high-shear conditioning (expander treatment; E) and expander-pelleting (EP), respectively. Expander-pelleting clearly improved the physical quality of pellets in terms of hardness and durability as compared to steam-pelleting. The apparent ileal digestibility of dietary nitrogen, dry matter, organic matter and crude fat determined with piglets in the weight range of 20–25 kg was not affected by the technological treatments under investigation. Only the crude fibre digestibility was significantly improved by single expander conditioning (P<0·05); the absolute level of 7·6% however was of low significance. Under the conditions of the present study, high shear conditioning (expander treatment) prior to pelleting showed no favourable effects on the apparent ileal digestibility of nutrients. Feed intake of the diets, offered in a choice feeding design to piglets of about 27 kg liveweight showed a large variation between piglets but in favour of the SP and E diet. Since diet hardness is related directly to the animal feed intake, maximisation of diet durability of expanded or pelleted diets should be achieved in relation to an optimisation of diet hardness and nutrient utilisation in piglets. © 1998 SCI.