July 22,1918 Composition and Digestibility of Sudan-Grass Hay 
177 
considerable extent to the lack of uniformity in the conditions under 
which curing takes place; so in Table II the various constituents are 
expressed as percentages of the total dry matter present in the samples 
of hay analyzed. 
Table II.— Composition of the dry matter of Sudan-gross hay 
Constituent. 
Maryland 
(< 5 ). 
Virginia 
U). 
Texas (p). 
Oklahoma 
0). 
Average. 
Total dry matter. 
Protein. 
Nitrogen-free extract. 
Crude fiber. 
Ether extract. 
Ash. 
Per cent, 
go. 12 
6- 57 
Si -99 
34-83 
1.88 
4 - 74 
Per cent. 
96. 49 
4- 83 
51.09 
36. 92 
I.32 
5* 85 
Per cent. 
12 . 42 
45 - 56 
29-93 
I. 92 
10. 16 
Per cent, 
92. 80 
8. 56 
48. 98 
34. OI 
2. 42 
6. 03 
Per cent. 
93 * 14 
8.10 
49 - 4 i 
33 - 92 
1. 89 
6. 70 
The analyses of Sudan-grass hay that have been reported are fairly 
uniform in all their constituents except protein and ash, which show 
rather wide variations, due perhaps to the conditions under which the 
crops were grown and the stage of growth at the time of cutting. 
It is generally understood that the majority of crops alter materially 
in composition as ripening progresses. This change is due not only to 
the increase in the amount of dry matter and the decrease in the amount 
of water but also to a variation in the relative proportions of the indi¬ 
vidual constituents of the dry matter. These changes usually go on 
until the crop is practically ripe, but that this is not so in the later 
stages of ripening in the case of Sudan grass has been shown by Piper 
(Table III). 
Table III.— Composition of dry matter of Sudan-grass hay (4) made at various stages 
of ripeness 
Stage of cutting. 
Before 
heading. 
Heads ap¬ 
pearing. 
Beginning 
to bloom. 
In full 
bloom. 
Seeds fully 
mature. 
Protein.. 
Nitrogen-free extract. 
Crude fiber. 
Ether extract. 
Ash. 
Per cent. 
8. 08 
5 1 * 2 3 
32.00 
1. 79 
6. 89 
Per cent. 
6. 28 
53 - 4 i 
33 - n 
1.44 
5-75 
Per cent. 
5 - 34 
53 - 76 
34-42 
I. 27 
5 - 20 
Per cent. 
4- 83 
51. 09 
36. 92 
1. 32 
5.85 
Per cent. 
4- 38 
55 - 85 
36.02 
i- 55 
5 - 85 
As would be expected, there is a decrease in the protein and a slight 
increase in the crude-fiber content. These changes are marked in the 
case of the protein, but the other constituents are fairly constant. The 
significance of this is that from the time Sudan grass heads out until 
it is fully ripe there is very little change in the fiber content of the dry 
matter, and consequently the time of cutting can be delayed without 
much risk of the hay becoming too coarse. This suggests a distinct 
