AbstractsBiology & Animal Science

According to the census figures there are approximately 20,000,000 cows used for dairy purposes in the United States at the present time. It is probably safe to assume that these cows are milked on the average not more than five years and that they have to be replaced when they are not more than seven years old. This means that practically 4,000,000 cows must be raised each year in order to keep up this number. Since the heifers do not come into milk until they are two years of age it is necessary at any one time to have approximately 8,000,000 heifers in the herds that are being raised to replace the cows then in use for milking purposes. According to data that has been gathered by experiment stations it apparently costs from $50.00 to $60.00 in the way of feed to raise a heifer to the age where she commences to return a profit in milk. These statements indicate the size and importance of the question of the proper feeding of dairy animals from birth to the time they come in milk. The larger number of these heifers are fed during the first six months of their lives on skim milk. This period of feeding has been made the subject of extended investigations and at the present time both investigators and practical men agree in regard to the best practice for feeding during the milk feeding period.