74 ILLINOIS STATE DAIRYMEN'S ASSOCIATION 



MINERAL NEEDS OF DAIRY COWS 



(F. B. Morrison, Professor of Animal Husbandry and 



Assistant Director of Agricultural Experiment 



Station, University of Wisconsin). 



At the present time, the importance of mineral matter 

 for live stock is receiving much popular attention, due 

 chiefly to striking results which have been secured in re- 

 cent experiments by nutrition experts. As a consequence, 

 many proprietary mineral mixtures are now being widely 

 advertised, often with extravagant claims. It is therefore 

 essential that stockmen understand clearly just how much 

 is known concerning the mineral requirements of live stock* 

 They can then supply any needed mineral supplements for 

 their stock at low expense, without spending unnecessarily 

 large sums on expensive preparations. 



Importance of Mineral Matter. 



That the mineral matter is of the greatest importance 

 to animals is shown by feeding rations freed as far as pos- 

 sible from it, in which case they die of mineral starvation. 

 Indeed, animals thus fed generally perish sooner than when 

 no food is given. During such starvation the nervous sys- 

 tem first suffers in a perceptible manner; marked weakness 

 of the limbs, trembling of the muscles, convulsions, and 

 grqat excitability result. 



Mineral matter is found in all the vital parts of the 

 body. The nuclei, or life centers, of all cells are rich in 

 phosphorus, and the skeleton is composed largely of cal- 

 cium (lime) combined with phosphorus. Blood deprived 

 of its calcium does not clot. The blood serum is rich in 

 common salt and other salts of sodium, while the red blood 

 corpuscles are rich in potassium compounds. The power of 

 the blood to carry oxygen is due to hemoglobin, an iron- 

 protein compound in the red corpuscles. In the stomach 



