Necrotic
enteritis caused by Clostridium perfringens has become prevalent in the European Union due to the withdrawal of
antibiotics in poultry feed. In an experiment with a 2 × 2 factorial arrangement, 336 one-day-old male broiler chicks (Ross 308) were assigned to 4 groups with or without C. perfringens challenge and fed wheat-based diets supplemented with or without xylanase at 5,500 U/kg of diet. The study aimed to investigate effects of xylanase addition on growth performance as well as nutrient digestion and absorption of C. perfringens-infected broilers. Before challenge (d 0-14), xylanase-supplemented birds had greater ADG and lower feed conversion ratio (FCR; P < 0.05). During
infection (d 14-21), challenge tended to decrease ADG (P = 0.063) and significantly increased FCR (P < 0.05), whereas xylanase addition greatly reduced FCR (P < 0.05).
Clostridium perfringens infection decreased
AME values and apparent ileal digestibility of DM of diets (P < 0.05). Xylanase supplementation increased
AME values regardless of
infection and apparent ileal digestibility of CP in challenged birds (P < 0.05). Activities of duodenal α-
amylase and
chymotrypsin and pancreatic
trypsin were decreased by C. perfringens
infection (P < 0.05). Xylanase supplementation elevated pancreatic
chymotrypsin activity and reduced duodenal α-
amylase and
trypsin activities (P < 0.05). It also decreased jejunal α-
amylase activity and increased pancreatic α-
amylase as well as jejunal
sucrase activities in uninfected birds (P < 0.05). The duodenal
mRNA expression of
sodium glucose cotransporter 1 (SGLT1), H(+)-dependent
peptide transporter 1 (PepT1), and
liver fatty acid-binding protein (L-FABP) were downregulated (P < 0.05), but ileal SGLT1 gene expression was increased by
infection (P < 0.05). Xylanase addition upregulated expression of jejunal SGLT1, PepT1, and L-FABP genes as well as ileal PepT1 and L-FABP genes in challenged broilers (P < 0.05). In conclusion, xylanase supplementation of wheat-based diets improved FCR and
AME in birds irrespective of C. perfringens
infection and elevated apparent ileal digestibility of CP and
mRNA expression of nutrient transporters in challenged birds.