A total of 300 growing-finishing pigs (30-110 kg BW), the offspring of Naima sows and Duroc boars, were allocated to three dietary treatments (five pens per treatment, 10 males and 10 females per pen). The growth performance of pigs was determined, and the apparent digestibility of nutrients and energy in animals fed grower diets was calculated by the simple balance method. Complete diets with a high content of triticale (70%-73%) and barley (6.8%-12%) were supplemented with endo-1,4-beta-xylanase (6200 EPU per g). The minimum xylanase activity per kg feed was 1050 and 1500 EPU. Xylanase, at activity levels of 1050 and 1500 EPU kg-1 complete diet, significantly (P≤0.05) increased the apparent digestibility of total protein and highly significantly (P≤0.01) that of crude fat. No significant differences in the digestibility of N-free extractives and energy were found between groups. The increased activity of xylanase (1500 EPU kg-1 feed) contributed to an increase in the digestibility of dry matter, crude fibre (P≤0.05) and organic matter (P≤0.01), compared with the control group. Higher (P≤0.01) daily gains and average final body weights were noted in pigs fed diets supplemented with the mono-enzyme preparation. The feed conversion ratio (FCR) tended to improve in pigs receiving xylanase-supplemented diets, but the observed differences were statistically non-significant.
