it shouldnt be limited to cows, we as sikhs need to save the world one step at a time, being vegan so simple but it has a huge impact, because its achievable through ommission, and we should be ethical as much as practically possible.
also like i keep saying, by bring vegan you are also helping to end human suffering, firstly by being more effective with food and grain on the earth,i.e if we dont feed the cows grain we can feed starving humans and end world hunger and also for helping over population in the world we use up 1/3 of the earths surface for animal agriculture, thirdly, less pollution which means less people are getting sick and we can be stewards of the earth like we should be.
all of this and more can be achieved just by choosing to eat one thing instead of another, whats wxcuse do you have not to be vegan ?