The performance of fattening cattle offered barley and grass silage in various proportions either as discrete feeds or as a complete diet

Seventy-two male castrates (60 British Friesian and 12 Lincoln Red Shorthorn × (Hereford × British Friesian)) were used. The barley was offered either once daily or in a homogenous mix (complete diet) at different proportions of the total dry matter. The diets ranged from silage alone to one of rolled barley plus 1 kg long hay per day. Animals on the complete diet had greater intakes (8·9%) than those offered their barley once daily but this was not reflected in significantly greater daily live-weight gains. Curvilinear regressions were fitted to the data but further investigations with different breeds of cattle and qualities of grass silage will be required before they can be used with any assurance for predictive purposes in advisory situations. When steers were fed on diets with more than 0·40 barley in the total dry matter their intakes declined but their calculated energy (MJ metabolizable energy) intakes remained similar. It is suggested that this finding should be taken into account when diets for cattle are formulated for advisory purposes.