Apparent digestibility (ileal and overall) of nutrients as evaluated with PVTC-cannulated or ileo-rectal anastomised pigs fed diets containing two indigestible markers

Abstract

The techniques of post-valve “T” caecal cannulation (PVTC) and ileo-rectal anastomosis (IRA) and the indigestible markers Cr 2O 3 and TiO 2 for determination of ileal digestibility of nutrients were studied in this experiment. The results showed that the marker Cr 2O 3 gave consistently lower ileal recovery and ileal apparent digestibility of nutrients. The average value of ileal recovery of Cr 2O 3 measured with the IRA method was only 87%. A nearly 100% of ileal recovery of TiO 2 measured with the IRA method suggests that the use of TiO 2 as a marker may be a better choice for determination of ileal digestibility of nutrients when partial-sampling ileal digesta. The reason for the lower ileal recovery of Cr 2O 3 may be due to the chemical analytical problems of Cr in excreta. The low recoveries of markers (TiO 2 67.8% and Cr 2O 3 60.6%) and the high values for ileal digestibility of nutrients in the high fibre content diet based on wheat bran (WB) measured by the PVTC total collection method indicated that a quantitative collection of digesta had not been achieved and hence that it is necessary to use a marker for the PVTC method. However, the results from the present experiment showed that there is a high ileal recovery of TiO 2 (95–100%) for the low and medium fibre diets based on wheat (W), recombined wheat (flour plus bran plus middlings, WR) and wheat middlings (WM) measured by the PVTC method. The ileal digestibility of nutrients measured by PVTC (TiO 2) agreed well with the IRA method for all of the for measuring the ileal digestibility of nutrients in pigs.