How have humans influenced the possible effects that a cow on its environment?

Answer 1

By the way they choose to raise that cow. A cow has a much more positive effect on the environment if she is raised as natural as is possible: like her ancestors the Aurochs lived, but with the use of managed grazing practices. A cow allowed to live/graze on pasture does much more good because her manure is going back into the soil to help plants grow and those plants help sequester (bring in) carbon from the atmosphere from the natural gases like methane and carbon dioxide and keep it there, essentially where it belongs.

A cow has a negative effect on the environment if she is kept in totally unnatural conditions, such as inside of a man-made structure where she doesn't have much room to move around and feed and water are brought to her. Her manure is piled up, which when moved onto the fields releases vasts quantities of methane and carbon dioxide. Fields have to be tilled to be able to grow crops again, and crops and hay production really "mine" the soil of its nutrients. Cows grazing in those fields on residue or in the pasture will put back more nutrients than will spreading manure from lagoons or manure piles will...supposedly.