Figure 2. A trench silo constructed for research work at the University. 



is fed to the calves. On other farms 

 little hay is fed until the calf is sev- 

 eral montlis old. In both cases a vit- 

 amin D deficiency is likely to result 

 if supplemental vitamin D is not fed. 



An attempt was made to study the 

 effects of vitamin D deficiency in an 

 experiment with calves fed a vitamin 

 D ration and maintained in the ab- 

 sence of sunlight. It was found that 

 the basal metabolism was increased 

 quite markedly in the deficient calves 

 long before any visible rachitic sym- 

 toms were observed. The protein in 

 the ration was utilized to a greater 

 extent by the calves when they were 

 given a small supplement of irradi- 

 ated yeast. The vitamin D supplement 

 also prevented rickets. From the re- 

 sults of the experiment, a moderate 

 supplement of vitamin D is recom- 

 mended in the ration of the calf not 



only to prevent rickets but to enable 

 it to make better use of its feed. 

 N. F. CoLovos, H. A. Keener, 

 A. E. Teeri and H. a. Davis 



Improving the Processing, Packaging 

 And Shipping of Bull Semen 

 Used for Artificial Insemination 



A container has been developed 

 for carrying bull semen by the tech- 

 nician while in the field. The con- 

 tainer consists of a copper can 5% 

 X 41/2 X 31/4 inches, with twelve % 

 inch copper tubes evenly spaced in 

 the can for holding the semen vials. 

 The vials are 12 x 75 mm. and hold 

 about 5 ml. of semen. 



In use, the container is nearly 

 filled with water and placed in the 

 freezing compartment of a refriger- 

 ator and left there until frozen solid. 

 The technician's kit has an insulated 



.23 



