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

The techniques of post-valve ‘‘T’’ caecal cannulation (PVTC) and ileo-rectal anastomosis (IRA) and the indigestible markers Cr O and TiO for determination of ileal digestibility of nutrients were studied in this experiment. The results 2 3 2 showed that the marker Cr O gave consistently lower ileal recovery and ileal apparent digestibility of nutrients. The 2 3 average value of ileal recovery of Cr O measured with the IRA method was only 87%. A nearly 100% of ileal recovery of 2 3 TiO measured with the IRA method suggests that the use of TiO as a marker may be a better choice for determination of 2 2 ileal digestibility of nutrients when partial-sampling ileal digesta. The reason for the lower ileal recovery of Cr O may be 2 3 due to the chemical analytical problems of Cr in excreta. The low recoveries of markers (TiO 67.8% and Cr O 60.6%) and 2 2 3 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 (95–100%) for the low and medium fibre diets based on wheat (W), recombined wheat (flour 2 plus bran plus middlings, WR) and wheat middlings (WM) measured by the PVTC method. The ileal digestibility of nutrients measured by PVTC (TiO ) agreed well with the IRA method for all of the for measuring the ileal digestibility of 2 nutrients in pigs.  2000 Elsevier Science B.V. All rights reserved.