Kautilya's Arthashastra 2.30.12

2.30.12

tataḥ paraṃ māsottaram ardhavṛddhir yavaprastha ātrivarṣāt, droṇa ācaturvarṣāt //

A colt, ten days old, shall be given a kudumba of flour mixed with ¼th kudumba of clarified butter, and 1 prastha of milk till it becomes six months old; then the above rations shall be increased half as much during each succeeding month, with the addition of 1 prastha of barley till it becomes three years old, then one drona of barley till it grows four years old; at the age of four or five, it attains its full development and becomes serviceable.