Because of the prevalence of cobalt deficiency during the 1944-45 barn 

 feeding season, it was natural that other conditions be called cobalt deficiency. 

 Thus, when each letter was received, the condition described was classified 

 as cobalt deficiency or not cobalt deficiency. During a period of about nine 

 months cobalt was sent to over 200 livestock owners. Reports were not ob- 

 tained from quite a few farmers, but the returns were as good as might be 

 expected from this tvpe of survey. It was found that the classification of cases 

 into cobalt deficiency or not cobalt deficiency was almost pexfect. indicating 

 that cobalt deficiency has rather definite symptoms which make the deficiency 

 rather easily identified in most cases. 



The information obtained in the letters describing the. condition and 

 reporting on the use of cobalt did not furnish reliable data on the relative 

 prevalence of the condition among different age groups, breeds, etc. To get 

 such information a brief questionnaire was sent to each person who had 

 used cobalt. Naturally, the returns also were not complete, but because of 

 the relatively large number, the data obtained presented a rather accurate 

 picture of the situation. 



Table 1 — Summary of Cobalt Trials and the Result Obtained 



Table 1 gives a summary of the use of cobalt and the results obtained in 

 each county. It can be seen that both the number of herds treated and the 

 percentage of animals affected per herd was highest in Carroll County, the 

 apparent original location of the deficiency. Hillsboro and Rockingham coun- 

 ties also had a lot of the deficiency, apparentlv due in part to the intensive 

 and extensive use of poultry manure on the land. Before the development 

 of the poultry industry in this area, cobalt deficiency apparently was not a 

 problem. The explanation for this situation appears to be this. There is a 

 certain amount of available cobalt present in the. soil for a crop. If it all 

 goes into a small amount of hay, there is enough present on the percentage 

 basis to prevent the deficiency. If the same amount is distributed through a 

 much larger quantity of hay. the amount present on a percentage basis may 

 be reduced to less than the amount required to prevent the deficiency. Poul- 

 try manure simply acted in stimulating the growth of the forage. 



Figure 1 gives a better idea of the relative prevalence of the deficiency 

 in various parts of the state. It can be seen that cobalt deficiencv was much 



