The use of whole oat in feed rations is restricted due to low digestibility of the hull. AC Assiniboia hulls have decreased acid detergent lignin (ADL) content. AC Assiniboia was crossed with OT 775 and the resulting lines were measured for ADL content. The ratio of F4:5 lines with low to normal ADL concentration fit a 1:1 genetic ratio. Indicating that the low-lignin trait is controlled by a single major gene. ADL concentration was correlated with hull colour and acid detergent fiber concentration. ADL concentration was not correlated with the protein or fat concentration of the groat. Simple inheritance of the low-lignin trait indicates that it can be incorporated into the oat breeding program. Furthermore, ADL concentration is not correlated with groat fat so a cultivar with a low lignin hull and high fat groat can be developed.