Minor Element Content of Forage 

 Con be Reduced by Heavy Use 

 Of Fertilizer and Lime 



The trend among progressive dairy- 

 men in this area is to apply com- 

 mercial fertilizer and lime more 

 heavily to the soils on which forage 

 crops are grown in order to obtain 

 greater yields per acre. The high 

 quality forage thus produced is past- 

 ured or harvested and stored so that 

 its feeding value will be as high as 

 possible. With this type of program 

 much less feed, particularly concen- 

 trates, is purchased from other farms 

 or from other areas of the country. 

 Other research has suggested that 

 such a situation may lower the minor 

 element content of the ration. In 

 order to determine what effect such 

 a program may have on the chemical 

 composition of the forage and on the 

 growth, reproduction and production 

 of cattle, a long time experiment is 

 being conducted. The forage is be- 

 ing grown at Northwood while the 

 cattle are being maintained under 

 controlled conditions at the Dairy 

 Husbandry Nutrition Research Barn 

 al Durham. 



During the first year of the ex- 

 periment timothy produced under in- 

 tensive fertilization was low in co- 

 balt, iron, and copper. The same was 

 true for brome grass. The ladino 

 clover with which the brome grass 

 was grown was lower than normal in 

 cobalt and iron, but it was not as 

 low in these elements as were the 

 grasses. Calves fed the timothy hay 

 developed marked cobalt deficiency 

 symptoms, while calves fed the la- 

 d]no-brome hay developed moderate- 

 ly severe cobalt deficiency. This is 

 contrary to the general opinion that 

 cattle which are fed a forage contain- 

 ing a considerable percentage of le- 

 gumes receive adequate cobalt. At the 

 present time cobalt deficiency is the 

 only deficiency which has been found 

 to affect the cattle on this experi- 

 ment in any way. Conclusions in re- 



gard to other elements will have to 



await future developments. 

 H. A. Keener 

 G. P. Percival 

 K. S. Morrow 



Radioactive Cobalt Used 

 In Mineral Studies 



Studies on cobalt deficiency at this 

 Station and elsewhere have shown 

 that when cobalt is fed to deficient 

 animals, recovery takes place very 

 rapidly. When cobalt is injected into 

 the jugular vein, however, larger 

 amounts of cobalt have to be given 

 and recovery takes place- more slow- 

 ly. If cobalt functions in the rumen 

 as has been believed generally, an 

 explanation was needed as to why 

 injected cobalt brought about any 

 response at all. 



In order to see if cobalt could 

 make its way into the rumen con- 

 tents from the blood stream, an ex- 

 periment was carried out in which 

 ladioactive cobalt was injected into 

 cobalt deficient sheep. A very small 

 amount of the injected cobalt was 

 found in the rumen contents and it 

 appeared to be enough to explain 

 the slow response from cobalt in- 

 jections. Using the radioactive iso- 

 tope, it also was found that cobalt 

 carbonate, which is relatively in- 

 soluble in water, can be absorbed 

 into the bloodstream in appreciable 

 quantities. It is known that cobalt 

 carbonate will relieve cobalt de- 

 ficiency. This work, however, does 

 not indicate just where cobalt car- 

 bonate goes into solution. 



H. A. Keener 

 G. P. Percival 



The Effect of Sulfathalidine on the 

 Excretion of Water-Soluble Vitamins 

 By Ruminants and on Their 

 Utilization and Digestion of the 

 Protein and Energy in the Feed 



Oral administration of sulfathali- 

 dine to heifers resulted in a signifi- 



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