Effect of Steam-Volatile Fatty Acids and Carbon Dioxide on Blood Content of Rumen Papillae of the Cow

SUMMARY Single rumen papillae were sampled from a conscious unrestrained cow with a rumen fistula, and the hemoglobin content of the papillae was determined. Carbon dioxide and steam-volatile fatty acids in the rumen increased the hemoglobin content. This effect was localized to the mucosal area of application. The mean hemoglobin content of rumen papillae was between 42.6 and 76.4 mg./Gm. of dry weight for papillae bathed by 154 mM sodium chloride and between 88.1 and 118.3 mg./Gm. of dry weight for papillae bathed by solutions of carbonic or steam-volatile fatty acids.