The effect of lactation on growth
There are five uses in general to which a dairy cow may put her feed. It may be used for maintenance, for growth, for the production of milk, for the laying on of fat and for the growth of the foetus. In view of the fact that steers continued to grow when on submaintenance and the highly developed dairy cow continued to give milk when starving, it seems to me that it would be interesting and important to determine if possible what happens when the impulse to grow and the stimulation to give milk are operative at the same time and at a time when, from the standpoint of nutrition, the animal has only about enough feed to satisfy one of the requirements. Does the animal stop growing and continue with the milk flow unaffected. or are the requirements for growth first satisfied and the remaining nutrients used for milk production, or is there a middle ground and each process suffers to a limited extent? Then too there arise practical questions. Can a dairyman afford to have his cows come into milk before they are full grown? By so doing will the animals be permanently stunted or will the amount of milk that the animal will be able to give be very materially lessened? Just how early will it be practical to have heifers calve?