28 CIRCULAR NO. 116, BUREAU OF PLANT INDUSTRY. 



REVIEW OF WORK DONE AND IN PROGRESS. 

 EARLY EXPERIMENTS. 



It is well known in the hay industry that the most important 

 factor in grading hay is its color. Preliminary tests to determine 

 the effect of the application of artificial heat to freshly cut alfalfa 

 showed no injury to the color by temperatures ranging as high as 

 150° to 180° F., and later tests have not only confirmed these results 

 but have shown that temperatures as high as 250° F. may be safely 

 applied under proper conditions. 



A chemical examination of the artificially cured hay to determine 

 its feeding value as compared with that of freshly cut alfalfa and 

 of alfalfa cured in the field by the ordinary process and stored in 

 the barn* till ready to bale showed that the artificially cured product 

 stands much higher in protein than the field-cured hay. The re- 

 sults of this examination are given in Table I. 



Table I. — Chemical analysis of alfalfa hen variously treated. 



Kind of hay. 



Green 



Field cured 



Artificially cured 



Reduced to water-free basis: 

 Green 



Field cured , 



Artificially cured 



Moisture. 



72.31 

 74.93 



16.72 

 17.19 



3.92 

 5.94 



Ether ex- 

 tract. 



0.84 

 .69 



1.71 



1.82 



2.67 

 3.58 



3.03 



2.05 

 2.19 



^.77 

 2.16 



Ash. 



2.71 

 2.36 



5.76 

 5.56 



9.13 

 8.23 



9.78 

 9.41 



7.03 

 6.71 



9.50 



8.75 



Crude 

 fiber. 



7.57 

 6.97 



23. 38 

 23. 37 



29.67 

 22.51 



27.33 

 27.80 



28.07 

 28. 22 



30.85 

 23.93 



Albumi- 

 noids (NX 

 6.25). 



5.37 

 4.75 



11.84 

 10.95 



16.96 

 18. 57 



19.39 

 18.94 



14.21 

 13.22 



17.65 

 19.73 



Nitrogen- 

 free ex- 

 tract. 



11.20 

 10.30 



40.59 

 41.11 



37.65 

 41.16 



40.80 

 41.04 



48.76 

 49.76 



39.17 

 43.: 5 



The early experiments showed that artificial curing was successful 

 in so far as color and feeding value, as determined by chemical ex- 

 amination, were concerned. 



Extended inquiry failed to discover any type of kiln on the market, 

 such as is in use for the drying of other products, that could be 

 made available for the haying industry. The pioneer work of de- 

 signing and erecting a drying plant encountered many difficulties; 

 and, in the absence of data for the solution of the various problems, 

 progress was necessarily slow. 



WORK IN THE YEAR 1909. 



As originally designed, the machinery of the hay-drying kiln con- 

 sisted of seven endless conveyors arranged in a building 20 feet high. 



[Cir. 116] 



