FEEDING MILKING COWS.

Waikato Times, Volume 108, Issue 18165, 1 November 1930, Page 22 (Supplement)

FEEDING MILKING COWS.

USE OF CALCIUM (LIME.) Heavy milking cows during the first half of the period of lactation on normal rations fed in qualities sufficient to maintain live weight invariably lose calcium from the skeleton in spite of adequate amounts of calcium in the ration. Even the feeding of large amounts of calcium to the rations in the form of bone-meal, calcium carbonate, calcium lactate, etc-, does not affect the position—the heavy milker still loses calcium from her bones. From experimental'work carried out at the State College at Pennsylvania, U.S.A., it is/shown that in the selective. improvement of the milch cow we have encountered limitations of capacity to assimilate mineral nutrients, especially calciiim. A complete study of the subjects- showed that the minerals in the skeleton were more readily available for use in milk production than the calcium compounds fed in the. ration. The explanation of this is that parturition lets loose a pent up flood of nutriment, which has been stored for the use of the calf. This outpouring of mineral-rich food proceeds in large measure, independently of the food supply, that is, if the food is just sufficient to maintain the life of the cow she will produce milk, even though this involves extensive removals from the tissues of her body. It should be obvious to any thinking individual that this giving out more than is taken in cannot go on indefinitely, and at some point between the middle and end of the period of milking wheh the impulse to secrete milk has spent itself, the milk production comes to be definitely related to and dependent on the feed intake and falls off in amount to such an extent that a fresh storing-up of calcium in the skeleton becomes possible. It is the duty of all cattle owners, to see that the female gets a chance to store up minerals against the time when the birth of another calf will once more require her to draw on the bones of her skeleton for a fresh supply/in excess of what she can take in. It is obvious, therefore, that a, cow should have a dry period of sufficient length, and feed during that time, to permit the entire replacement of the preceding mineral development. Dry the cow off in good time and feed well if you want good results. —Land.