Feed intake, growth, digestibility of dry matter and nitrogen in young pigs as affected by dietary cation-anion difference and supplementation of xylanase

An experiment was conducted to test the effect of dietary cation-anion diff erence (CAD, Na+ + K+-Cl-, mEq/kg diet) and xylanase addition on feed consu mption, digestibility of nutrients, plasma electrolyte balance and growth p erformance in young pigs. A 2 x 3 factorial arrangement with three dietary CAD levels (-100, 200, and 500 mEq/kg) and two levels of xylanase supplemen tation (0 and 0.1% xylanase derived from Trichoderma longibrachiatum) was u sed. Thirty-six individually housed, castrated pigs (5 weeks old) with an i nitial body weight of 9.34 +/- 0.28 kg (mean +/- SEM) were randomly assigne d to the six treatments. Diets were provided to pigs as cold pellets. Pigs had ad libitum access to feed and water. Venous plasma Cl- concentration wa s higher (p < 0.0001) in dietary CAD of - 100 mEq/kg group compared with th e other two CAD groups. Dietary CAD did not affect Na+ and K+ concentration s in the venous plasma. Growth rates were higher (p < 0.05) in pigs receivi ng dietary CAD of 200 mEq/kg (657 g/pig.day) and dietary CAD of 500 mEq/kg (603 g/pig.day) than in pigs receiving dietary CAD of -100 mEq/kg (484 g/pi g.day). Faecal dry matter and nitrogen decreased with increasing dietary CA D. Faecal apparent digestibility of dry matter and nitrogen was higher (p < 0.05) in the dietary CAD of 500 mEq/kg compared to the two lower level CAD groups. Supplementation of xylanase did not affect the performance of pigs . Xylanase addition in the diet significantly increased apparent faecal dig estibility of dry matter and tended to increase apparent digestibility of n itrogen. No interaction between dietary CAD and xylanase was found. In conc lusion, dietary CAD influenced the performance and digestibility of nutrien ts of pigs. Xylanase supplementation improved digestibility of dry matter.