Abstract: | The effects of a commercial xylanase preparation on the apparent metabolisable energy and ileal amino acid digestibility values of wheat (n = 2), triticale and wheat middlings for five-week-old broiler chickens were investigated. The apparent metabolisable energy and ileal amino acid digestibilities in wheat 1 (new season) and wheat 2 (old season) were improved (P < 0.05) by the supplemental enzyme. The apparent metabolisable energy values (MJ kg−1) of wheat 1 and wheat 2, without or with the enzyme, were 13.71 and 14.40, and 14.28 and 15.34, respectively. The average digestibilities of the 15 amino acids in wheat 1 and wheat 2, without or with the enzyme, were 0.85 and 0.91, and 0.85 and 0.90, respectively. Exogenous xylanase was without effect (P > 0.05) on the apparent metabolisable energy values of triticale and wheat middlings. Although numerical advantages in the amino acid digestibility of triticale and wheat middlings were observed with enzyme addition, the differences were not significant (P > 0.05) except for phenylalanine, lysine and glycine in the wheat middlings. © 1999 Society of Chemical Industry |