Barley and wheat require processing for feeding to cattle otherwise large amounts of whole grain pass through the animals undigested. Processing methods can be mechanical, such as rolling or grinding, or chemical, such as sodium hydroxide treatment - a method which is in common use on dairy farms in the UK. Although ammonia treatment of cereal straws is widely practiced on farms - where it results in an improvement in straw digestibility, voluntary intake and crude protein content, the use of ammonia for treating cereal grains has not been investigated in the UK. Ammonia treatment of moist grain has the potential to (1) preserve it, thus avoiding drying or preservation costs, (2) make investment in grinding/rolling equipment unnecessary, (3) increase its crude protein content and (4) make it a safer feed compared with mechanically processed grain which frequently causes digestive disorders when fed in large amounts. The aim of the current study was to investigate the use of ammonia-treated barley and wheat, fed whole, in diets for beef cattle.