Study of The effect of formaldehyde levels on rumen fermentation kinetics and in vitro digestibility of two barley varieties

Chemical composition, gas production, kinetic fermentation and in vitro digestibility of two Iranian barley varieties (hulled and hull-less) and also the effect of 3 and 4.5% formaldehyde concentrations on fermentation kinetics and in vitro digestibility of these varieties was investigated. Produced gas was recorded at different incubation times and fermentation parameters, potential gas production fraction (b), rate of fermentation (c) and delay phase (lag) were determined from cumulative gas production. There were significant differences in terms of chemical composition, kinetic parameters of fermentation and Dry matter and Organic matter digestibility of two varieties (P<0.05 (. Hull-less barley with lower ADF and NDF and higher CP had greater gas production and hulled variety with higher cell wall content lower CP had lower gas production. Kinetic and in vitro digestibility of both varieties were treated by formaldehyde had significant differences in compare with controls (P<0.05(. Both levels of formaldehyde treatments reduced gas production and fermentation rate of the both cultivars, the 4.5% level of formaldehyde had significant differences with 3% level of formaldehyde and control(P<0.05(.