Measurement of precaecal dietary protein and plant cell wall digestion in pigs; comparison of four surgical procedures for ileorectal anastomosis

Abstract

Ileorectal anastomosis (IRA) is commonly used to study the partitioning (precaecal vs. postileal) of digestion of carbohydrates and proteins in the pig. Based on an interlaboratory study (Saint Gilles, Exp.G and Rostock, Exp.R), four possible IRA procedures have been compared: end to end or end to side anastomosis, with or without valve (EEV, ESV, EE, and ES, respectively). In each place 25 pigs were allotted to 5 groups [including intact (INT) pigs]. After recovery, three 7 day collection periods were carried out at 30, 60 and 90 kg live weight under pair feeding conditions. Digestion coefficients were calculated for nitrogen, amino acids, starch, fibre (estimated by van Soest procedures) and nonstarch polysaccharides. Analyses were performed in the same laboratory (amino acids: Rostock, carbohydrates: Saint Gilles). Despite minor differences with respect to the place, the experiments led to common conclusions. The ES models do not provide correct digestibility values due to backflow and bacterial metabolism. The EE models seem to be the most appropriate to study ileal digestibility of proteins, even in the long term. The EE models can also be used to measure the ileal digestibility of fibre, but only in short term experiments and in this case the preservation of the valve could be of interest.