Methodik zur in-vivo-bestimmung der praecaecalen verdaulichkeit von vitaminen

The aim of this investigation was to examine in initial experiments the suitability of using ileorectalanastomosis (IRA) in pigs for the determination of precaecal digestibility as a measure of the availability of native B-vitamins. Therefore, six growing female pigs of about 30 kg liveweight received end-to-side ileorectalanastomosis with the preserved ileo-caeco-colic valve. From 40 to 70 kg liveweight, or from day 15 to 25 to day 60 to 67 after surgery, metabolism trials were carried out, collecting digesta and urine quantitatively. Precaecal digestibility of vitamin B₆ and of the vitamers pyridoxin, pyridoxal and pyridoxamin (PN, PL, PM) from corn, wheat bran and dried skim-milk was examined with six animals each. The examined feedstuffs were fed together with a nearly vitamin-free ration so that the animals were supplied with all nutrients optimally during the whole experiment. Precaecal digestibility of vitamin B₆ was 90 % in dried skim-milk, 71 % in corn and 61 % in wheat bran. Concerning the vitamers, PL had the highest digestibility of 81 %, whereas PM was, with 63 %, significantly less digestible; with 69 %, PN ranged between both. The suitability of the method for the determination of vitamin availability is discussed.