The aerodynamics of a cow will be as a blunt object. The air mostly sees the front of a body and then flows according to the shape pattern behind. Earlier the experiments were done in the wind tunnel to determine and know the flow pattern of air over the object. The experiment shows the streamline flow of air over an object whose shape is oval or streamline like the airfoil. These kinds of objects can generate lift if its shape is little bit changed making flow over the airfoil little faster than the flow down the airfoil. So by modifying the shapes a varying amount of lift can be generated. These types of bodies are known as a body of aerodynamic shapes.

Unlike the aerodynamic streamline bodies, a body which obstructs the flow of air is a blunt body. These types of bodies create the largest amount of drag and very less amount of lift. Blunt bodies are non streamlined bodies, like cuboid, spherical and cylindrical shapes. These bodies obstruct the flow of air. 

A cow

So any bodies which are blunt will not produce any streamline flow of air. Even cars and other vehicles are now designed to have an aerodynamic shape so that there is very less drag on a vehicle, making it to have an advantage of low consumption of fuel and higher speed. Animals like cheetahs which run very fast make their body streamlined to achieve a very high speed while running. Cows and other herbivorous animals do not run for prey, so their body need not be streamlined for a smoother, faster flow of air.

A running cheetah