362 FEEDS AND FEEDING 



larger amounts of a vitamine (possibly the fat-soluble vitamine) which 

 is necessary for the assimilation of calcium from the food. (104) 

 This hypothesis is borne out by the fact that in certain instances where 

 cows have been maintained without pasture or other green feed, they 

 are less thrifty and the production is lower than normal. 88 



In experiments at the Beltsville, Maryland, Station of the United 

 States Department of Agriculture 60 by Meigs and Woodward, the pro- 

 duction of cows which had but little pasture or green feed during the 

 year was increased in the following lactation period by adding sodium 

 phosphate (a soluble phosphate) to the concentrate mixture fed during 

 the dry period of 60 days before freshening. About 10 Ibs. of sodium 

 phosphate (Na 2 HP0 4 . 12H 2 0) was added to each 100 Ibs. of the con- 

 centrate mixture, and the cows were fed a daily average of 3 to 6 Ibs. 

 of concentrates, with corn silage and alfalfa hay. The effect of the phos- 

 phate feeding was not noticeable in the case of cows that had been very 

 liberally fed the preceding year because they had been on official test. 



These various trials emphasize the importance of pasture and other 

 green forage for dairy cows during the growing season, and of an 

 abundance of well-cured legume hay during the rest of the year. Also, 

 the cows should be dry from 6 to 8 weeks before freshening, and during 

 this time should be so fed that they will be in good condition at calving. 

 ( 661 ) When plenty of legume hay is not available, or when for any other 

 reason there is possibility of the supply of calcium or phosphorus in 

 the ration being low, mineral supplements should be added to the ration. 

 Both calcium and phosphorus may be supplied by adding 3 to 4 Ibs. of 

 steamed bone meal or ground rock phosphate to each 100 Ibs. of the con- 

 centrates, or only 2 Ibs. if the ration is already fairly high in calcium and 

 phosphorus. That abortion or weak calves result when pregnant cows 

 receive rations low in lime, such as straw with grain and grain by- 

 products, has been pointed out in a previous chapter. (98) 



If trouble is experienced from goitre or "big neck" in calves, this 

 may be prevented by the administration of iodine to the cows thruout 

 pregnancy, as is discussed in Chapter IV. (101) According to Kalkus 61 

 of the Washington Station, the iodine may be given by any one of the 

 following methods: (1) Two grains of potassium iodide per head 

 daily may be mixed with the feed. This may be done conveniently by 

 sprinkling on the feed one tablespoonful of a solution of one ounce of 

 potassium iodide to one gallon of water. (2) One teaspoonful of 

 tincture of iodine may be poured on the pregnant animal's back once 

 every two weeks. The iodine should not be poured on the same spot 

 each time or it will blister the skin and cause the hair to fall out. (3) 

 Ten cubic centimeters (about one-third ounce) of a 10 per ct. solution 

 of iodine may be injected under the skin of the cow with a hypodermic 

 syringe every two weeks during pregnancy. The same doses can be used 

 for mares as for cows. 



"Ohio Bui. 346, p. XXIV. "U. S. D. A. Bui. 945. "Wash. Pop. Bui. 117; Bui. 156. 



