Altered Cattle

Changes that cattle can see once they have been altered, would consist of them physically becoming larger in size. The larger size results in the affected cattle's meat and skin becoming droopy, hanging off of the animal (in some cases affected cattle have had skin and muscle droop so low that it scraps across the ground as they move). This would mean they possess more meat.
Altered cattle also see changes to the size and power of their legs. This allows the creature to be able to support this new overall increase in size and mass. With this they have also had an increase of sharpness and size in their hooves (allows them to more easily dig into the ground when moving for more stability).
These creatures posses larger mouths which allows them to consume an increased amount of flora more effectively.

Altered Cattle's Behaviour

The altered cattle become extremely timid, straying away from areas they know posses life (other than their own species). However, some affected cattle have been known to become calm around other life when peacefully exposed to them for long enough (this is although a rare occurrence, and takes extreme patience from the other life from to successfully accomplish).
With this more timid behaviour, the altered cattle have been able to take advantage of their long drooping skin and muscle. They have used this to effectively blend in with certain environments by laying down and letting their skin and muscles droop over them, ultimately creating shapes that can resemble small boulders and rocks.
Similarly to unaltered cattle, these affected creatures still remain and navigate in large herds, however they do not hesitate to split up when put into  specific situations (encountering other life for example).