The effect of chemical treatment of barley on starch digestion in ruminants

Two experiments were conducted with sheep and Jersey cows to study the effects of formaldehyde (HCHO) treatment of barley on rumen fermentation, flow of starch to small intestine and its subsequent apparent digestion. HCHO was applied to barley at a rate of 30 g HCHO kg−1 barley crude protein (CP). Diets containing either untreated barley (UB) or HCHO treated barley (TB) were fed to sheep and cattle for a period of 4 weeks in two separate cross-over design experiments. Rumen degradability of DM, starch (S) and total N was assessed by the in sacco technique, flow of nutrients to intestine and microbial protein reaching the duodenum were also determined. Treatment of barley with HCHO did confer some resistance to degradation on the starch and protein components of barley as reflected in the results from the in sacco experiment. However this resistance was not enough to increase S or total N flow to the small intestine, or to alter the concentrations of rumen metabolites or microbial protein reaching the intestines in either sheep or cattle.