Other Forage Quality Indices 
Forage Pa!atability 
Palatability is that quality in a forage plant 
that makes it preferred when a choice between 
plants is available. It has been defined as the 
relative relish with which forage plants are 
consumed (National Academy of Sciences-Na- 
tional Research Council 1962). 
The production of grazing animals largely 
depends upon (1) the amount of forage in- 
gested and (2) the level of individual nutri- 
ents. Palatability may be equal to, or more 
important than, nutrient content because it 
directly influences the rate and total intake of 
forage (Hurd and Blaser 1962). 
Palatability varies with species, location of 
animals, and previous experience, and it is in- 
fluenced by the interrelationships of plant, ani- 
mal, and environmental factors. Some studies 
have established that animals generally select 
forage high in important nutrients (Swift 
1948), whereas other studies have shown cor- 
relations ranging from zero to high (Hurd and 
Blaser 1962). It is generally agreed, however, 
that plants high in sugar content are eagerly 
sought by ruminants. 
Regardless of the relations between the pal- 
atability of forage and its nutritional value, 
any evaluation of the overall quality of a plant 
should include relative palatability because of 
its important effect on forage intake. 
Other Forage Attributes 
There are many attributes of plants that 
have been used to estimate forage quality. 
Some of the more useful ones are: 
Federal hay grades. —The U.S. Department 
of Agriculture has formulated a grading sys- 
tem for hay based upon visual estimates of 
odor, color, leafiness, stem texture, and amount 
of foreign matter. The hay grades generally 
reflect the responses of growing cattle and 
milking cows to various qualities of hay. The 
hay grades are not precise enough, however, to 
accurately predict the feeding value of forage 
grown on a given farm (Reid et al. 1959). 
Leaf content.—The leafiness of a forage is 
usually highly correlated with its nutritive 
value, because the leaves generally contain 
higher levels of important nutrients than the 
stems. Plant leaves contain more protein, phos- 
phorus, calcium, and carotene, while the stems 
contain more fiber (Dietz et al. 1958). A wide 
leaf-to-stem ratio would indicate higher nutri- 
tive value than a narrow ratio (Reid et al. 
1959). 
Botanical composition. —Forage quality can 
be measurably influenced by the different pro- 
portions of the various plant species ingested 
by animals on the range. The use of forage leg- 
umes has been widely advocated, and has led to 
the inference that the nutritive qualities of leg- 
umes are superior to those of nonlegumes. 
There is evidence, however, that grass forage 
with an adequate protein content may produce 
animal responses (body weight gain, milk 
yield, etc.) equal to those from grass and leg- 
ume mixtures because the energy production of 
the two sources may be approximately the 
same. In some situations, inadequate levels of 
protein and certain minerals in grasses could 
result in reduced animal response (Reid et al. 
1959). 
DISCUSSION AND SUMMARY 
A review of the literature on forage quality 
provides the impression that, after a slow, 
faltering start, rapid progress is now being 
made. Almost all advances in both human and 
animal nutrition have been made in the past 50 
years. Even with our increased knowledge, 
many problems associated with the concept of 
forage quality must still be solved. It is doubt- 
ful whether all the essential nutrient compo- 
nents for any species have been discovered 
(Maynard and Loosli 1956). 
Many nutritional terms and tests, as well as 
other indices of forage quality, have been de- 
scribed in this paper. Which of these are most 
practical for the range technician to consider 
in evaluation of forage for livestock and wild- 
life? The proximate scheme of analysis, while 
useful, should be superseded by the newer 
techniques because of inherent weaknesses in 
describing the carbohydrate portion. For rumi- 
nant animals the following variables are rec- 
ommended for consideration in routine analy- 
ses: Dry matter, gross energy, crude protein, 
fiber, lignin, cellulose, ash, calcium, phospho- 
rus, and beta carotene. The information pro- 
vided by these determinations should be of 
great practical value in most range forage 
evaluations. More information on certain min- 
erals may be needed in areas where deficiencies 
are known to occur. Information concerning 
crude fat may be valuable for some shrub 
ranges containing plants with high true fat 
content. 
An additional step in evaluating forage 
value is the determination of animal response. 
Palatibility is also important, because it di- 
rectly influences feed intake. However, some 
plants may be very valuable on the range even 
when their palatability is rather low if they 
contribute essential constituents, such as vita- 
mins and minerals to the diet when other more 
palatable plants are deficient, in these nutrients. 
Forage quality can be better evaluated by de- 
termining forage digestibility by various 
classes of ruminants. As previously described, 
there are many techniques for determining for- 
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