ARTIFICIAL DRYIXG OF FORAGE CROPS 



27 



The digestibility of the nutrients in forage is not impaired by de- 

 hydration, provided the forage is not exposed to excessive drying 

 temperatures (table 6). It should be pointed out. however, that the 

 digestibility of the protein may be lowered if the exhaust temperature 

 of the dehydrator exceeds 350° F.. in which case the feeding value of 

 the forage would be affected materially. 



Several experiment stations have considered the possibility of sub- 

 stituting dehydrated forage, made from crops cut at an early stage 

 of maturity, for all or part of the grain or for part of the forage in 

 the usual dairy ration. That such substitution might be feasible is 

 indicated by the composition of early-cut forages as compared with 

 some of the feeds commonly fed to dairy cows (table 7) . These figures 

 show that, on the basis of total digestible nutrients, dehydrated young 

 grass is intermediate in value between the regular hays and grains 

 fed to dairy cattle. 



In feeding trials at the Vermont Agricultural Experiment Station, 

 in which dehydrated young grass was substituted for all the concen- 

 trates and the cows continued to receive full amounts of hay and silage, 

 milk and butterfat yields were lowered, apparently because of the 

 excessive bulk of the ration. In other trials at the same station, in 

 which dehydrated young grass was substituted for some of the grain 

 and for one-third of the usual amount of hay and silage, cows produced 

 as much milk, and they produced it almost as efficiently, as when they 

 were fed full allowances of grain, hay, and silage. The young grass 

 contained 20.4 percent of crude protein, 17.6 percent of crude fiber, 

 40.2 percent of nitrogen-free extract. 3.4 percent of ether extract, and 

 63.6 percent of total digestible nutrients, whereas the corresponding 

 percentages in the grain ration were 20.4. 6.3, 51.9, 4.5. and 72.9. 



In feeding experiments conducted by the Bureau of Dairy Industry 

 in cooperation with the Washington Agricultural Experiment Station, 

 it was concluded that artificially dried pasture herbage containing 20.7 

 percent of protein and 15.8 percent of crude fiber could be used effi- 

 ciently in replacing at least a part of the concentrate mixture for milk- 



In another experiment by the Bureau of Dairy Industry, four cows 

 that were fed dried immature pasture grass as the sole ration averaged 

 11,325 pounds of milk, which was 64.6 percent of their average pro- 



Table 7. — Comparative composition of grains, hays, and dehydrated young grass 



: i 



Feed 



Grain mixture ' 



Corn No. 2 - 



Barley 



Dehydrated young grass ! 



Dehydrated young Sudan grass 



Dehydrated pasture herbage 3 



Dehvdrated alfalfa leaf meal 



Alfalfa* 



Timothy hay ] 



Dry Crude 



matter protein 



Percent 



85.0 

 89.4 



90.5 

 86.3 



Percent 

 20.6 



8.6 

 12.7 

 20,7 

 14.2 

 24.6 

 18.9 

 14.8 



7.3 



Crude 

 fiber 



Percent 



6.7 



2.0 



5.4 



17.4 



18.8 



18.1 



24.3 



28.9 



30.1 



Xitrogen- 

 free extract 



Percent 

 51.4 

 69.3 

 66.6 

 40.7 

 42.4 

 39.2 

 38.1 

 36.6 

 42.4 



Ether 

 extract 



Percent 

 4.5 

 3.9 

 1.9 

 3.3 

 ?.4 

 3.5 

 2.8 

 2.0 

 1.5 



Total di- 

 gestible 



nutrients 



Percent 

 72.6 

 80.1 

 77.7 

 64.1 

 58.9 

 64.7 

 54.7 

 50.3 

 46.6 



i Camburn, O.M. 1934. The feeding value of artificially dried young grass, III. Vt. Agr. Expt. Sta. 

 Bui. 36S, 10 pp. 



2 Newlander, J. A. 1935. The digestibility of artificiallv dried Sudan grass. Vt. Agr. Expt. Sta. Bui. 

 386, 8 pp.. illus. 



3 Hodgson, R. E., and Knott, J. C 1932. Apparent digestibility of, and nitrogen, calcium, and phos- 

 phorus balance of dairy heifers on, artificially dried pasture herbage. Jour. Agr. Res. 45 (9): 557-563. 



* Morrison, Frank B. 1948. Feeds and feeding, a handbook for the student and stockman. Ed. 21, 

 unabridged, 1207 pp., illus. Ithaca, X. Y. 



