the objective of this study was to determine the effects of diets having different fermentability on blood gases, blood metabolites and ruminal fermentation parameters in holstein dairy cows. four multiparous holstein dairy cows (665 ± 25 kg bw, 170 ± 7.0 dim and 15±1.5 kg of milk yield), fitted with rumen cannulae, were used in a 4×4 latin square design with 28-d periods. corn starch and sucro...