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 Cr2O3 and TiO2 for determina tion of ileal digestibility of nutrients were studied in this experiment. T he results showed that the marker Cr2O3 gave consistently lower ileal recov ery and ileal apparent digestibility of nutrients. The average value of ile al recovery of Cr2O3 measured with the IRA method was only 87%. A nearly 10 0% of ileal recovery of TiO2 measured with the IRA method suggests that the use of TiO2 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 Cr2O3 may be due to the chemical analytical problems of Cr in excreta. The low recoveries of markers (TiO2 67.8% and C r2O3 60.6%) and the high values for heal 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 PV TC method. However, the results from the present experiment showed that the re is a high ileal recovery of TiO2 (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 digest ibility of nutrients measured by PVTC (TiO2) agreed well with the IRA metho d for all of the for measuring the ileal digestibility of nutrients in pigs , (C) 2000 Elsevier Science B.V. All rights reserved.