FIFTY-THIRD ANNUAL CONVENTION 45 



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

 calving. This rest period will give them an opportunity to 

 rebuild the stores of calcium and phosphorus in their bodies, 

 which may have been depleted by the drain of milk pro- 

 duction. 



Practical Pointers on Minerals for Dairy Cows 



On account of the great importance of supplying cows 

 plenty of minerals, it may be well to summarize very briefly 

 and definitely the recommendations with reference to this 

 matter : 



In the usual dairy ration there is more danger of a lack 

 of calcium than three is in phosphorus. This is because 

 most of the common protein-rich feeds are also rich in phos- 

 phorus. This includes wheat bran in particular and also 

 wheat middlings, cottonseed meal, and linseed meal. Glu- 

 ten feed, germ oil meal (corn germ meal), brewers' grains 

 and distillers' grains are not especially high in phosphorus. 



When 20 per cent or more of the concentrate mixture 

 or grain mixture consists of wheat bran, wheat middlings, 

 linseed meal, or cottonseed meal, the cows will get plenty of 

 phosphorus. If less of these high-phosphorus feeds is fed, 

 it is best to supply additional phosphorus by adding bone 

 meal, as stated later. 



A large production of milk and thrifty calves are an 

 impossibility if there is a lack of calcium in the ration. The 

 best way of furnishing plenty of lime is to grow and feed an 

 abundance of alfalfa, clover, or soybean hay whenever it 

 is possible. All legume hays are rich in lime. Furthermore, 

 well-cured, green colored hay, cured in the sun, contains 

 the vitamin which animals need to enable them to assimi- 

 late and use the calcium in their feed. 



If poor roughage must be used, such as hay from the 

 grasses (not legumes) corn stover grown on acid soil, or 

 straw, add 3 to 4 pounds of ground limestone, wood ashes, 

 or dried marl to each 100 pounds of concentrate or grain 

 mixture. Preliminary experiments indicate that dolomitic 

 limestones, which are high in magnesium may be used sat- 

 isfactorily as a source of lime. 



If there is not 20 per cent of high-phosphorus feeds in 

 the concentrate mixture (wheat bran, wheat middlings, lin- 



