Different types of fibre sources were used in high fibre diets to increase feeding quantity and measure the effect on different parameters in two experiments. In exp. I, three diets (A, commercial control diet; B, high insoluble fibre content; and C, high soluble fibre content) were fed to 10 groups of 12 broiler breeder chickens (age: 2 to 15 weeks). Similar growth rates were obtained on different quantities of food (e.g. food allocation in week 14: approx. 80, 100, and 130 g/d for A, B, and C, respectively) with all birds reaching commercial target weight at 15 weeks of age. Birds fed A ate significantly more in a hunger test than birds on diets B and C, indicating that these two high-fibre diets did reduce the level of hunger experienced by the birds. Stereotypic pecking was most frequently seen in birds fed A and never observed in birds fed B. Birds on diet C appeared scruffier in their plumage, and the higher water content of their litter may have affected their thermoregulation. In exp. II, four diets based on different fibre sources were given to broiler breeders from day 12 to 19 weeks of age to increase feed quantity. Diet A (commercial control diet: 10.7MJ/kg), B (42% dietary fibre (DF); 7.25MJ/kg), C (38% DF; 7.25MJ/kg) and D (30% DF; 8.00MJ/kg) were fed each to 8 groups of 28 chickens. Weights of intestinal segments and their contents were measured at 4, 9 and 14 weeks. Behavioural observations were carried out at 18 weeks. From 19-30 weeks all groups were fed the same commercial pre-layer and layer diets. Similar growth rates were obtained on different quantities of food (e.g. food allocation in week 16: 75, 100, 110 and 92 g/d for A, B, C and D, respectively). The higher amounts of food offered on the high fibre diets compared to feed A was detectable in the intestinal contents, with high fibre feed staying longer in the intestinal system. Birds fed fibre diets displayed more dust bathing and less stereotypic behaviour. Egg production did not differ between the diet treatments. The results from the two experiments show that high fibre diets prolong the passage of feed and reduce stereotypic behaviour, indicating an improvement in the well-being of the birds, who may experience less hunger than commercially fed broiler breeders.