Mr.Srinivas,
It depends on location of dairy farm. Anyway, to supplement the
a) carbohydrate - South african tall Maize / fodder sorghum (jowar) / fodder bajra (pearl millet) in summer and oat in winter in about 1.5 acre
b) protein - berseem in winter and lucerne (alfalfa) / cowpea in summer in about 0.5 acre or glyricidia/caliandra/subabul trees on the boundary
c) You can prepare the silage from the cereal crops and hay from the leguminous crops, which can be fed to the cows during fodder off season.
Seeds should be available in the local fodder / agriculture / animal husbandry department located at taluka / district headquarters. The price of seeds would be very nominal (may be Rs.20-Rs.50 per kg, you may need 2-10 kg seeds per care depending on the type of seed)
Silage will be prepared by chaffing the cereal fodder (2" long) and keeping in airtight condition for 45-60 days. Before covering with plastic or mud, it should be pressed such that the excess air is removed from the fodder. There will be fermentation process lactic acid will be produced which induces more milk production and the silage will be ready. You can also add 1 kg urea, 2 kg jaggery/molasses, 1 kg common salt, 1 kg mineral mixture per ton of chaffed green fodder. Prepare the solution of these ingredients and sprinkle over the chaffed fodder and press, cover it.
Regards
parameshwar Hegde