252 Western Live-stock Management 
which are especially good for the growing horse, also 
contain a considerable amount of energy, and from 
this standpoint would be good for the hard-worked horse, 
but because of their washy effect, they are less desirable 
than some of the less nutritious hays, such as timothy. 
Timothy does not contain a large amount of digestible 
nutrients, but because of its favorable influence on the 
digestive system of hard-worked horses, it has long been 
the common practice to use it almost exclusively and de- 
pend on grain for most of the energy or digestible nutrients. 
In some sections rolled barley and wheat hay are used 
extensively. Either of these feeds has a tendency to 
cause impactions. In using feeds of such nature, it is 
desirable to use some laxative feed, such as alfalfa hay 
or bran, which will tend to keep the bowels open and have 
a favorable action on the digestive organs. Thedemands 
of the work horse for protein and mineral matter are com- 
paratively small and there are very few feeds commonly 
used which do not contain a sufficient amount of these 
nutrients. A slight excess of protein will not be harmful, 
for it may serve the same purposes in the body as carbohy- 
drates and fat; that is, for the production of energy. 
There is a limit, however, to the amount of protein which 
may be successfully fed. All of the nitrogen taken 
into the body must be taken out by the kidneys, and an 
excess of protein will produce disorders of these organs. 
The amount of protein which may be fed to a horse varies 
greatly with different individuals, and there is no way to 
tell in advance just where the limit lies. The feeds which 
produce the largest amount of net energy or digestible 
nutrients are the grains and mill feeds, as corn, barley, 
oats, bran, and oil meal, and it is on such feeds that the 
horse must largely depend for the energy to perform hard 
