A comparative evaluation of ileo-rectal anastomosis techniques for the measurement of apparent precaecal digestibilities of folate, niacin and pantothenic acid

In this study two techniques of ilco-rectal anastomosis were compared for t heir use as a valuable measure of apparent precaecal digestibility of the B -vitamins folate, niacin and pantothenic acid. For that purpose three femal e pigs were each provided surgically with an end-to-side ileo-rectal anasto mosis and five female pigs were fitted with an end-re-end ileo-rectal anast omosis, both techniques with preservation of the ileo-caecal valve (ESV vs EEV). After surgery, the pigs were allowed a 3-week recuperation period bef ore starting the digestibility trial. For the measure of vitamin digestibil ity the animals received 1.5 kg/day of a fresh wheat diet (62% wheat) with defined amounts of native folate, niacin and pantothenic acid, and digestib ility was recorded from week 4 to week 9 and week 12 to week 17 after surge ry. Each animal was fed the experimental diet for 12 days, and digesta were collected twice daily quantitatively for the final 5 days. Folate, niacin and pantothenic acid in food and excreta were determined microbiologically. At week 17 after surgery, under conditions of restricted energy intake, gr owth response and feed efficacy of all animals were within normal limits. S urgical procedure effect was significant for all the apparent precaecal dig estibilities of the B-vitamins measured, in which the vitamin concentration s excreted via the chyme were distinctly higher in animals fitted with the ESV than in animals fitted with the EEV, indicating that the ESV procedure may permit some bacterial fermentation to take place. Moreover, the finding s revealed no significant difference in apparent vitamin digestibility betw een the two time periods over which the wheat diet was given. Finally, it w as concluded that ESV models do not provide correct digestibility values du e to digesta Lack flow and microbial growth, bur the enteric modification o f an EEV model has been shown to be a valuable measure in determining the a pparent digestibility of vitamins from foods and foodstuffs.