Studies were conducted to evaluate the effects of tannins on in sacco
disappearance in the rumen and post-ruminal digestion using the mobile bag and pepsin-pancreatin (in vitro
) methods, and the tube-feeding technique in poultry. The treatment of Lotus pedunculatus
with PEG increased in sacco
disappearance compared with untreated lotus. Quebracho tannin (QT) reduced the disappearance of lupin seeds and soyabean meal. No effect of QT was found on the disappearance of chickpea, and an increase was observed for the disappearance of pea.
Tannins increased the excretion of nitrogenous compounds and sialic acid, and reduced nutrient digestibility of most feeds tested, as measured by the4 poultry model. Tannins reduced the proportion of uric acid nitrogen in the excreta. Tannins in lotus reduced intestinal digestion of N as measured by mobile bag and in vitro methods. Nitrogen digestibility of soyabean meal and chickpea as measured by the mobile bag and in vitro methods was not affected by QT. Mimosa tannin (MT) inhibited the attachment of microbes to cellulose and decreased gas production. Polyethylene glycol completely restored the gas production from cellulose treated with MT. Pectin improved microbial attachment in the presence of MT, and the inhibition of the gas production from cellulose was partially restored. The gas production from maize shoots decreased with MT, and it was restored with the addition of PEG. Pectin did not improve the gas production from MT-treated maize shoots. The presence of both MT and pectin improved EMPS, but reduced the incorporation of 15N into microbial protein.