Mammary blood flow and venous drainage in cows.

The mammary blood flow and the udder drainage in vivo evaluated using the antipyrine absorption method has been compared with the anatomical findings in the udder after slaughtering of the experimental cows (Table 1). Because of the orientation of the valves in the perineal veins and blood samples taken in vivo it must be assumed that the perineal veins lead blood toward the veins at the udder base. It is concluded that the drainage of the udder in standing cows will primarily be through the milk veins, eventually there will be a flow of non-mammary venous blood down the external pudic veins at the udder base, as in the case of the perineal veins.