The sulfur appeared in the blood within four hours from the time silage 

 feeding started and in the milk at the next milking, which was in 15 hours. 

 Approximately two thirds of the sulfur was absorbed and one third passed 

 through the body in the feces. Most of the absorbed sulfur was excreted in the 

 urine while only 1-2.6 percent of the radioactive sulfur fed appeared in the 

 milk. 



The results of this experiment indicate that sulfur from sulfur dioxide 

 used as a silage preservative probably has some value nutritionally. On the 

 other hand, the heavy feeding of such silage requires the elimination of rather 

 large amounts of sulfur by the kidneys. Although this has not been proven 

 to be harmful, it does indicate need for further study. 



The project was done in cooperation with R. V. Harrington and R. R. 

 Baldwin of Central Laboratories, General Foods Corporation, Hoboken, N. J. 



H. A. Keener, A. E. Teeri 



Minor Element Content of Forage Can Be Reduced by Heavy Fertilization. 



Research work conducted at this Station and elsewhere has shown that 

 as the yield of forage increases the cobalt content of the forage tends to de- 

 crease. Because of the increasing acceptance of the intensive type of rough- 

 age program, it seemed that if this principle applied to other minor elements, 

 deficiencies other than cobalt might eventually affect the livestock of the area. 

 Accordingly, an experiment to study this situation was started in 1949. 



The first year the forage crops were heavily fertilized; both timothy 

 and brome grasses were very low in cobalt, iron, and copper. Ladino clover 

 was lower than normal in cobalt and iron, but not as low as the grasses. Last 

 year cobalt remained at about the same level, but the amount of copper in 

 all species was reduced somewhat. This was particularly true for ladino clover 

 in which copper was only about one third the level of the previous year. 

 In fact, the copper content of the ladino clover was lower than that of the 

 brome grass with which it was growing. This is rather surprising in view of 

 the generally accepted idea that legumes are generally higher in minerals 

 than the grasses. The manganese content of all the forage species has re- 

 mained within the normal range. 



The low cobalt content of the forage resulted in cobalt deficiency in 

 dairy heifers in about six months. This was true for both timothy hay and 

 ladino-brome hay. After cobalt deficiency was encountered all animals were 

 given supplemental cobalt so that other deficiencies would not be masked. All 

 normal animals then seemed to develop normally for nearly a year, when 

 apparently another deficiency appeared, first in the animals being fed tim- 

 othy hay and later in those receiving ladino-brome hay. This condition is 

 characterized by anemia in animals of all ages, also a misshapen spine in 

 older animals, and poor growth rate in calves. Copper deficiency is suspected, 

 but definite conclusions must await further studies. There is no indication 

 that the low mineral content of the ration has affected the reproductive per- 

 formance of the heifers adversely in their first gestation. 



The project was done in cooperation with K. C. Beeson and E. J. Thacker, 

 U. S. Plant, Soil, and Nutrition Laboratory, Ithaca, N. Y. 



H. A. Keener, F. E. Allen 

 K. S. Morrow, G. P. Percival 



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