Grass silage is the basic component of diets for winter or year-round feeding of beef cattle in Central and Northern Europe, but its quality can vary considerably. The aim of this study was to determine whether the quality of silage influences the fattening performance of crossbred steers and whether higher intake of supplementary concentrate improves performance in steers fed silage of lower quality. The experiment was conducted on 52 crossbred steers with the initial body weight of 300 kg, produced by crossing Polish Holstein-Friesian dairy cows with Charolais, Limousin and Hereford bulls. The animals had ad libitum access to one of two types of grass silages (of higher and lower quality), and silage intake was recorded individually. Supplementary concentrate consisted of crimped triticale grain (785 g kg-1), rapeseed meal (190 g kg-1) and a mineral-vitamin premix for beef cattle (25 g kg-1). Concentrate was administered at two levels of 1.9 and 2.4 kg dry matter per day. The animals were housed in a free-stall system and feed intake was recorded individually. The fattening period lasted 65 days. Live weight gains were higher (P

22.4.2016