Hi use the following thumb rule
Stage of lactation Quantity of green grass to be give (kg) for animal weighing Concentrate ( kg)
250 kg 300 kg 350 kg
Dry cow 25 kg 30 kg 35 kg For non-pregnant cows no concentrate is required.
Pregnant cows should be fed additional quantity of 1.5 kg of concentrate from
7th month of gestation
In case of dry cow, allowance up to 1 kg concentrate can be given if the
condition of cow is poor or the fodder quality is inferior.
Milch cow 25 kg 30 kg 35 kg 1.0 kg for every 2.5 kg of milk of average 4% fat percentage, in case of buffalo
1.0 kg for every 2.0 kg of milk produced.
Regards
Harish