ARTIFICIAL DRYING OF FORAGE CROPS 23 



of the grass fed did not result in a greater degree of calcium deposition. 

 Either the green or the artificially dried grass was as efficient in pro- 

 ducing calcification as was similar grass that was cured by exposure 

 to 15 hours of sunlight. The results of this experiment are not in 

 accord with the results of an experiment conducted by Bechdel 7 at 

 the Pennsylvania station who found that there was an appreciable 

 difference in the antirachitic potency of artificially dried alfalfa hay 

 and sun-cured alfalfa hay when fed to 6-month-old dairy calves. A 

 severe rachitic condition developed during a 6-month feeding period 

 when 1 pound of artificially dried hay was added to the basal diet, 

 and a mild rachitic condition developed when 1 pound of sun-cured 

 hay was added. As much as 2.5 pounds of artificially dried hay did 

 not prevent the development of a mild rachitic condition, while the 

 same amount of sun-cured hay prevented the appearance of rickets. 

 Perhaps the calcifying power of the artificially dried pasture herbage 

 was due to the fact that the grasses were immature and growing 

 rapidly at the time of cutting. 



In the second experiment 8 digestion trials were conducted with 

 sheep on mixed pasture grasses that were artificially dried at exhaust 

 gas temperatures of 250°, 300°, 350°, and 400° F. to determine the 

 effects of these temperatures on the digestibility and availability of 

 the nutrients in the pasture herbage. The results were that the 

 percentage of apparent digestibility of the feed constituents of the 

 rations of sun-cured grass and of the grass dried artificially at exhaust- 

 gas temperatures of 250°, 300°, and 350° showed no significant differ- 

 ences, indicating that artificial drying under these conditions had no 

 depressing effect on the availability of the nutrients. The percentage 

 of apparent digestibility of the nutrients in the sun-cured and in the 

 artificially dried grasses at 250°, 300°, and 350° averaged for dry 

 matter, 76; for crude protein, 76; for crude fiber, 83; for ether extract, 

 73; for nitrogen-free extract, 83; and for ash, 44. 



The results of the feeding trials of the material dried at 400° F. 

 showed that this temperature for the exhaust gas from the drier had 

 a depressing effect on the apparent digestibility of the crude protein, 

 dry matter, and nitrogen-free extract. There was also evidence of 

 the burning of some portions of the more leafy material when dried 

 at the outlet temperature of 400° F. The apparent digestibility of 

 most constituents was somewhat lower for the green grass than for 

 the material dried at 250°, 300°, 350°. As the exhaust temperature 

 of drying was increased by 50° intervals there was a definite lowering 

 of the percentage of natural color in the herbage. That dried at 

 400° had only 76.3 percent as much color as that dried at 250°. 



7 Bechdel, S. L., and others, rickets in calves. Pa. Agr. Expt. Sta. Bull. 291, 41 pp., illus. 1933. 



8 Hodgson, R. E., Knott, J. C, Graves, R. R., and Murer, H. K. effect of temperature of 



ARTIFICIAL DRYING ON DIGESTIBILITY AND AVAILABILITY OF NUTRIENTS IN PASTURE HERBAGE. JoUT. Agr. 



Research 50: 147-164; illus. 1935. 



