82 ILLINOIS STATE DAIRYMEN'S ASSOCIATION 



ing 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. 



Summary of Mineral Needs of Dairy Cows. 



For ready reference the following paragraphs may be 

 found of convenience. These give in brief form simple 

 directions with reference to the use of minerals in practical 

 dairy rations. 



Always Supply Plenty of Common Salt. 



Dairy cows must have plenty of salt in order to thrive. 

 Allow them to have free access to salt or feed it to them in 

 their feed. Many dairymen mix 0.5 to 1 pound of salt with 

 each 100 pounds of concentrated mixture or grain mixture, 

 and then supply salt in addition so the cows can take what 

 they wish. 



Salt is cheap. Don't neglect supplying it. 



Guard Against Goiter. 



If trouble has been experienced from goiter or "big 

 neck" in calves, this may be prevented in the future by giv- 

 ing potassium or sodium iodide to the cows throughout the 

 gestation period. Where there is no trouble from goiter, 

 this treatment is not needed. 



The iodide can be conveniently given by the following 

 method : Make up a solution of 1 ounce of potassium iodide 

 or sodium iodide to one gallon of water. Sprinkle on the 

 feed for each cow daily during pregnancy one tablespoon- 

 ful of this solution. This amount will contain 2 grains of 

 the drug, which is the desired daily dose. 



Cows Need Plenty of Calcium (Lime) and Phosphorus. 



Milk is very rich in both calcium (lime) and phos- 

 phorus. Therefore, dairy cows must receive liberal sup- 

 plies of both these minerals to secure continued high pro- 

 duction and to have a thrifty offspring. In the usual dairy 



