Shah,
While cattle can eat and are fed many things they do best on grass and as consistent a diet as you can manage. In many countries they get fed grain but this is not what they are designed to eat and they do best on grass. There are many other things that will influence their production also, mineral and salt, water intake and how far they have to walk, whether they get adequate social and laying down time a day. Cattle do best when they are in an environment that changes as little as possible, where they get good parasite and insect control and are not exposed to climate extremes. Hope this helps.