FEEDING OF, COWS

Hawke's Bay Herald-Tribune, Issue 196, 4 September 1937, Page 17

FEEDING OF, COWS

Effect of Iodine on Milk Yields The one outstanding solution to tho dairyman's problem is more ndlk from fewer cows. That means culling out the low producer aud feeding the good cows well-balanced diefcs, including essential minerals, In a word, he must make nine good cows produce what 10 ordinary cows did before. The mineral requirements of a dairy cow are particularly high, inasmueh as a cow giving f our gallons of milk a day secretes in the milk loz. of calcium (CaO) aud 1 3-10oz. of phosphorus (P205). Either she must get this s.upply of mineral from her feed and water supplies or elso rob her own body of these minerals (says the Jersey Bulle* tin). It is common knowledge that a cow may lose as much as 20 per cent. of the mineral majftef of its skeleton during a single lactation period. This means that minerals must be constantly fed to sl'em this heavy draiu. If assimilation or use of these minerals is largely dependent upon the secretion of the thyroid glan-d, and these secretions in turn are dependent upon suffieient iodine, one readily realises the importance of feeding suffieient iodine i.n order to obtain high milk production, and at the same time reduce feeding costs. Monroe, at the Ohio State Experiment station, in his work with dairy cattle, found that the addition of a small amount of iodine to the ratious of cows resulted in a 9 per cent. inerease in milk flow and a corresponding saving in feed costs. Orr, of tha Rowett Institute, Aberdeen in eommeuting on the use of iodine for dairy cattle, writes: "In the

case of milk cows, a German experiment station has reported increased milk yield of from 8 to 10 per cent. as a result of giving potassium iodine." In dairy tests conducted in Wisconsiu over a periqd of "two yearg, the average of 22 experiments showed a total iucrease of 4 per cent. of milk ahd 5,3 per cent, of butter-fat in favour of iodine feeding. The result of 45 experiments with one year records shows an average of 4.7 per cent. more milk from iodine* fed cows as compared with cows not fed iodiua.