Efficiency and dose response of xylanase in diets for fattening pigs

The efficiency of different levels of dietary xylanase on growth performance, nutrient digestibilities and carcass and meat quality was evaluated in 128 barrows. The performance study lasted from about 27 to 110 kg of body weight with pigs allocated to 4 groups (32 animals each), fed ad libitum and kept in straw-bedded pens (4 animals each). Pigs from group I (control) received standard feeds without any enzyme added, while pigs from groups II, III and IV received the same diet including additionally xylanase at levels of 8000, 16000 or 24000 BXU (Birch Xylan Unit) per kg, respectively. The digestibility experiment was carried out with 40 barrows not involved in the first part of the experiment. Pigs were allocated to 4 groups (10 animals each) receiving the same diets as in the performance experiment. Xylanase significantly improved body weight gains of pigs receiving diets with 16000 BXU/kg (P<0.05) and 24000 BXU/kg feed (P<0.01) by 4.2% and 6.2%, respectively. Final body weights of 111-112 kg were achieved in a significantly shorter feeding period and at a lower feed conversion ratio by pigs that received highest xylanase application (24000 BXU/kg feed, P<0.05). In younger pigs xylanase mainly improved fibre digestibility which was significant for pigs receiving 24000 BXU/kg (P<0.05). In the final feeding period dry matter, fat and fibre digestibility were improved by xylanase with effects getting more pronounced with the increase of xylanase inclusion rate. No differences in carcass and meat quality were observed between any feeding groups. Based on these results it is assumed that application of xylanase (Econase XT) can improve performance of grower-finisher pigs without having any impact on the carcass quality. Performance improvements were in line with better nutrient digestibility.