MINERAL COMPOSITION OF CROPS 11 



The phosphorus content of the alfalfa from even the better areas is 

 about as low as that found anywhere in the world for this plant when 

 harvested at the one-half bloom stage. (See appendix.) The calcium 

 is slightly below average for alfalfa, but the Ca:P ratio is 10 as com- 

 pared with 7.5, the ratio of the average values shown in the appendix. 

 The phosphorus contents of the clovers from both regions are not of 

 sufficient difference to be significant. The analyses of the wild grass 

 samples do indicate a difference of phosphorus, although the amount 

 found in the deficient areas is not so low as it was in the pasture grasses 

 studied by Theiler (table 2) . It is instructive to note that the calcium 

 content of forages from deficient areas was generally found to be 

 higher than in those from the normal areas, which may mean that a 

 Ca :P ratio less favorable to the animal is a factor to be considered. 



According to Eckles, Becker, and Palmer (161), mineral deficiencies 

 in cattle have been noted in 32 counties in Minnesota. The soils, 

 which at one time were covered with grass, are of glacial origin and are 

 described as young gray drift. While the phosphorus contents of the 

 forages from these areas show some differences according to the preva- 

 lence of disease, it must be admitted that they are all very low. For 

 example, the average phosphorus content of 9 samples of alfalfa from 

 normal regions in Minnesota was 0.257 percent, and that from 

 abnormal regions was 0.189 percent, while the average of all available 

 data for alfalfa at one-half bloom stage is 0.272 percent. The average 

 prairie hay in abnormal regions contained only 0.100 percent of phos- 

 phorus, while that from normal regions contained 0.108 percent. Such 

 differences are probably negligible, and the forages in the good regions 

 are probably on the border line as far as their nutritional value is 

 concerned. 



In harmony with the results from other deficient areas, it was found 

 that osteomalacia was more severe in years of drought than in wet 

 years. Likewise, the forage contained more phosphorus in the years of 

 higher rainfall. 



Later work from Minnesota by Eckles, Gullickson, and Palmer (162) 

 showed extreme cases of phosphorus-deficient forage in prairie hay 

 grown on the Nygaard farm. From 1925 to 1931 the phosphorus 

 contents of the hay from this farm varied from 0.047 to 0.094 percent. 

 Such values compare very well with the results of Theiler in South 

 Africa, and they are lower than the values found in Montana. It was 

 estimated by the authors that a cow receiving this hay along with the 

 usual ration of oats would receive only 68.6 percent of the phosphorus 

 necessary for maintenance and milk supply. 



Huffman and Taylor (281) in 1926 surveyed areas in Michigan where 

 depraved appetite occurred and found that soils in these areas con- 

 tained approximately one-half as much phosphorus as did normal soils. 

 Analyses of three samples of forage collected by these investigators do 

 not indicate a phosphorus deficiency, but the rather unusual circum- 

 stance is presented of a low phosphorus content in their forage samples 

 collected in the early spring followed by a 40-percent increase by mid- 

 summer and a further increase by fall. They state that depraved 

 appetite in Michigan cattle seemed to be most severe in the spring and 

 abated during the fall. They further found that, although a mineral 

 mixture similar to the mineral combination found in alfalfa hay failed 

 to relieve depraved appetite, well-cured alfalfa hay effected a cure in all 

 cases tried. 



