United States. Bureau of Animal Industry.

Special report on diseases of cattle and on cattle feeding online

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and the young tick soon gets upon any northern cattle which happen
to be on the pasture. As soon as they have attached themselves to the


skin they inoculate tlie cattle and Texas fever breaks out a week or
more thereafter. That ticks may and do produce Texas fever had been
suspected for many years in various parts of the country. A definite
proof was not offered, however, and the experiments carried on by the
Bureau of Animal Industry were the first to demonstrate this impor-
tant fact. It is not within the seope of this work to describe the steps
by which this conclusion was reached, nor the experiments made in
this direction. These will be found in the forthcoming report. There
are some important facts in the disease itself cleared up by these
experiments which require mention here.

The so-called period of incubation. After the young ticks have
attached themselves to cattle the fever appears about ten days there-
after iu midsummer. When the weather is cool, as in autumn, this
period may be a little longer. The actual period of incubation may be
shorter than this, for if blood from a case of Texas fever be injected into
the blood-vessels of healthy cattle the fever may appear within five days.
When cattle graze upon pastures over which Southern cattle have
{>;i-.-ed, the time when the disease appears varies within wide limits.
When the animals have been put upon pastures immediately after
Southern cattle have infected them with ticks, it may take from thirty
to sixty days, or even longer, before the disease appears. This will be
readily understood when we recall the life history of ticks. The South-
ern cattle leave only matured ticks which have dropped from them.
These must lay their eggs and the latter be hatched before any ticks
can get upon native cattle. The shortest period is thus not less than
thirty days, if we include ten days for the period of incubation after
the young tick has attached itself to native cattle. When the infec-
tion of pastures with ticks has taken place early in the season, or when
this is coldj the period will be much longer because it taTtes longer for
the eggs to hatch.

If native cattle are placed upon pastures which have been infected
.some time before with ticks, the disease will appear so much sooner
because the young ticks may be already hatched and attack the cattle
at ouee. It will be evident, theretore, that the length of time elapsing
bet ween the <ujpoliit of native cattle on infected fields and the appear-
ance of the disease will depend on the date of original infection and on
the weather, whether cold or hot. When native cat tie are placed upon
fields on which young ticks are already present they will show the lever
iu thirteen to fifteen days if the season be hot.

The fever appears before the ticks have matured. In fact they are
still small enough to be overlooked. In any case very careful search
should be made for them in those places upon which they prefer to
locate, the thighs, escutcheon, and udder. After the acnte stage of the
fever has passed by the ticks begin to swell np and show very plainly.
(Plate xi.iv. Figs. 6 ami 7.)

Preretttion. So far as our experiments have gone they indicate that


Texas fever is carried north only by the cattle tick. That there may be
other sources of infection can not be denied, but if there be such they
come into operation rarely and perhaps in very restricted localities.
Hence, to prevent Texas fever north of the permanently infected area
is to keep the pastures free from cattle ticks, and to do this no Southern
cattle with ticks must be allowed upon them. Ticks may, however,
reach pastures in other ways. Cattle cars from the South may leave
the sweepings and manure in places where cattle may get access to
them. These will contain ticks or eggs which will give rise to a brood
of young ticks in due time, ready to inoculate cattle when the opportu-
nity presents.

How to rid pastures of ticks without destroying the vegetation upon
it we do not know at present. Every pasture once infected is dangerous
during the entire season. Fortunately the winter destroys the tick and
afresh importation from the South is necessary to produce the disease
again during the following season. This is not strictly true for sheltered
places near the Texas-fever line, for they may live through very mild
winters in such places and produce disease the following summer. The
precise temperature at which the egg or the various stages of the cat-
tle tick are destroyed can not be accurately ascertained, because it
depends on the amount of protection and shelter which they may obtain.
It is therefore impossible to state how late in the winter ticks carried
from the South are still likely to perish in the North before the ensuing
spring. We know that cold greatly retards the development of ticks
in the egg and afterwards, and that any fatal disease in cold weather is
not likely to occur, but if the ticks should survive until summer the
danger of an outbreak is imminent. This danger diminishes, of course,
the farther north we go and the period of time during which ticks may
be carried thither with impunity is greater, owing to the longer season
of cold.

Treatment. When the disease has broken out, all animals, the sick
as well as the healthy, should at once be removed to another non-
infected pasture. While this may not cut short the disease, it may
save the lives of some by removing them from the possibility of being
attacked by more young ticks. Removal from infected pastures like-
wise prevents a second later attack in October or early in November,
which is caused by another generation of ticks. It is true that sick
natives infect with a new generation of ticks the pasture to which they
are removed, but these usually appear so late that they have but little
opportunity to do any damage. Hence, sick natives do not, as a rule,
cause visible disease in other natives.

It is of importance to remove all ticks, as far as this is possible, from
sick animals, since they abstract a considerable amount of blood and
thereby retard the final recovery. No systematic experiments have as
yet been made in the medicinal treatment of the sick, as the study of
the cause of the disease has taken all the time that could be given to


these investigations in past years. Sulphate of quinia, in doses of 15
to 30 grains, according to the size of the animal, has apparently given
good results in the hands of some veterinarians, and tincture of aconite
root and Epsom salts have been combined with it according to indica-
tions of the individual cases.

The previous pages have reference only to northern pastures. Whether
the tick alone, or perhaps other pests also infect cattle which have been
taken south, \ve are unable to state without having recourse to experi-
mental inquiries. It is reasonable to assume, however, that the same
causes are operative in the permanently infected area, and that ticks
must be kept away from imported animals, especially during the warmer
half of the year if disease is to be prevented.

Of the means by which ticks may be most easily and effectually
removed from cattle or kept away from those not yet attacked, noth-
ing definite can be said at present, and there is abundant room for
experimentation in this direction, especially within the area perma-
nently infested with the cattle tick.

Sanitary regulations. The disease, outside of the infected district,
may be prevented by proper regulations governing the movement of
cattle from that district during the season of the year that infection is
possible. Such regulations are now made yearly by the Secretary of
Agriculture. They define the boundary of the infected district, and
provide that no cattle shall go out of it except for immediate slaugh-
ter during that portion of the year included between the dates of Feb-
ruary 15 and December 1. Cattle from the district going to slaughter
can not be driven, but must be shipped by rail or boat. The waybills
and cars are marked " Southern cattle " when they cross the boundary
line, and when they are unloaded for feeding, watering, or sale they
are placed in pens set apart for such animals and into which native
stock is not allowed to go. The cars and boats which have trans-
I>orted such cattle must be cleaned and disinfected before native stock
can be carried.

By these simple regulations the disease has been almost entirely pre-
vented during the last two years, and little or no hardship has been
caused to those shipping r handling cattle from the infected district.
This success is one of the best illustrations of the value of proper reg-
ulations made in accordance with the principles of veterinary science
and intelligently administered.



[Description of plates.]

PLATE XLII. Fig. 1. Spleen of an acute fatal case of Texas fever. The narrow
end of the spleon is here represented. Fig. 2. Spleen of healthy steer. Though the
latter animal weighed one-half more than the former, the weight of the diseased
spleen, 6| pounds, was nearly three times that of the healthy spleen, 2| pounds.

PLATE XLJII. Showing the cut surface of a healthy liver taken from a steer
slaughtered for beef. Fig. 2. Showing the cut surface of the liver in Texas fever.
Fig. 3. Represents the appearance of the urine in an acute fatal case of Texas fever.
Fig. 4. Shows red corpuscles, magnified a thousand diameters, containing the par-
asite of Texas fever. This appears as a blue point, a, near the edge of the corpuscle.
The blood was taken from a skin incision. The case was non-fatal and occurred late
in fall. Fig. 5. Shows red corpuscles from the blood of an acute fatal case, tweuty
hours before death. The Texas fever microbes, , are shown as pear-shaped bodies
stained with methylene blue within the red corpuscles. The larger body on the
right, &, is a white blood corpuscle also stained with methylene blue. Magnified
a thousand diameters.

PLATE XLIV. The cattle tick, the carrier of Texas fever. Fig. 1. A series of ticks,
natural size, from the smallest, just hatched from the egg, to the mature female ready
to drop off and lay eggs. Fig. 2. Eggs, magnified 5 times. Fig. 3. The young tick
just hatched, magnified 40 times. Fig. 4. The male after the last molt, magnified
10 times. Fig. 5. The female after the last molt, magnified 10 times. Fig. 6= A por-
tion of the skin of the udder, showing the small ticks. From a fatal case of Texas
fever produced by placing young ticks on the animal. Natural size. Fig. 7. A por-
tion of the ear of the same animal showing same full-grown ticks, ready to drop off.
Natural size.

Fig. 3




Kip. 1

9 J 3 : 'J

Pig. 3


Kip. 7

nil'! c.vr'ri.H: TICK rm: < .\!.'I.'II-:K (>i n-:\.\s i i ATI.'



Professor of Agriculture and Director of the Agricultural Experiment Station, University

of Wisconsin.

Ten years ago the cattle business of the country was undergoing a
great and wonderful change; companies were being formed to control
vast herds which were to range unrestrained over the western plains,
with no provisions as to feed except the seeming abundance of natural
grasses, and little care except rounding up and branding. With this
unprecedented expansion came the natural attendant of good prices
for cattle of almost any quality in the older agricultural sections, and
beef- producers everywhere made money. It mattered little in Illinois
or Iowa whether a fattening steer ate half a bushel of corn a day or
only a third of a bushel, for there was proftt in the business, and giv-
ing attention to little details about feeding was not to be thought of in
such times. Those fanners who had advanced in dairying far enough
to make line goods likewise found high prices awaiting their products
and were satisfied to continue their feeding operations with little
thought of closer economy.

But times have changed; the young stock bought from our western
farms at good prices to go to the plains proved fruitful and multiplied
amazingly, and hordes of their descendants have been coming back
year after year to aid in depressing t lie cattle market. Dairy products
have kept up wonderfully well, but I do not think we can hope for higher
prices at any time than have ruled the past year.

We are passing through a period of lulling prices which began years
ago with the manufacturer, carrier, and merchant, and which is now
bearing down most heavily upon our agricultural industries. The mar-
velous advancement made in transportation facilities the world over
has brought about a new let of conditions; stock, bred thousands of
miles apart and reared under the most diverse conditions of range, cli-
mate, feed, and cost of production, meet at the great commercial cen-
ters, to be sold according to supply and demand, quality alone being
the varying factor. The problem is still further complicated by the
production of meat in distant parts of the world, which is now shipped
as frozen carcasses to the great meat consuming centers. Nor is there
any going backward in this matter. We can not hope that any of the



potent forces now at work, which all tend to equalizing the markets,
will cease for even a single day. While legislation may aid in some
minor matters, the general law that supply and demand rule prices
remains inviolable. I know of but two means of successfully meeting
the sharp competition which is certain to continue, first, by making
products of a higher quality, and, second, by cheapening the cost of

While lack of space prevents more than a mere mention of the sub-
ject, I can not help but urge that our farmers and stockmen endeavor
to secure the very best machines possible for converting coarse feeds
into beef and dairy products. To have any other than the best cattle
obtainable for the specific purpose in view is to start handicapped in
what is sure to be a severe contest.

In the other line of improvement there is also much opportunity for
careful study and the exercise of discretion and good judgment. The
farmer and stockman should have a clear knowledge and good under-
standing of the several different kinds of stock foods, their relative
values, and the combinations of those best suited for different animals
in different stages of growth and usefulness. With an earnest desire
to help the feeder in the study of the great problem which constantly
confronts him this chapter is written.


Fifty years ago those great lights in agricultural chemistry, Liebig,
of Germany, Boussingault, of France, and Lawes and Gilbert, of Eng-
land, began investigations of agricultural problems, many of which
were immediately helpful to agriculture and all tended to awaken an
interest in an art previously neglected by scientific investigators. Out
of this awakening grew the movement for a better knowledge of animal
nutrition, and how and by what means the products of our fields were
manufactured into flesh, milk, and other animal products. Germany
has led the world in founding agricultural-experiment stations, and to
German chemists and animal physiologists are we largely indebted for
what is known in this most important field. Though the investigations
began over a generation ago and have occupied the energies of many
eminent men, the records of whose observations fill hundreds of books,
so great is the subject that it now seems but fairly begun. Still, much
has been found that is of great importance and utility to the practical


Mainly through the studies of the German investigators has come
the first attempt to place the great art of feeding on a scientific basis.
The various investigations in animal nutrition have been summarized
and set forth in the writings of Wolff and Kuehn, of Germany, and very
ably presented to English readers by Dr. Armsby in his " Manual of


Cattle Feeding." The leading features of this system have also been
given in some of the reports of our American experiment stations.
Being largely the result of German investigations and formulations, it
is naturally spoken of as the "German system," while the tables of
data relative to feeding stuffs and feeding rations are usually spoken
of as the German feeding tables or the tables of Kuehn or Wolff, as
compiled and arranged by those writers.

Table I of this chapter presents the studies of chemists both in this
country and abroad, summarized and placed in the most available con-
densed form. The figures giving the composition of fodders are in most
cases taken from the compilation of analyses of American fodders by
Dr. E. H. Jenkins and A. L. Winton, jr., first published in Volume II
of the Experiment Station Record, Department of Agriculture (pp.
702-709). That portion of the table which gives the digestible constit-
uents was derived from the first part of the table through coefficients
of digestibility given by Dr. Jenkins in the Report of the Connecticut
Experiment Station for 1886 or from later sources.

There was a time when farmers thought that science, and even agri-
cultural science, could bring little that would be helpful to them, but
happily that day is past, and I approach the scientific side of the sub-
ject of feeding with no fear whatever that it will prove uninteresting
to my readers, but rather that a large majority will gladly avail them-
selves of any opportunity which may offer for a better understanding
of the great problem of stock feeding. It will be remembered in study-
ing the table that like most first attempts at definite expression of diffi-
cult and complex problems, what is here given is but a crude expres-
sion of important laws, and that the tables will no doubt be consider-
ably modified or perhaps supplanted in time by better ones, when the
animal physiologist has enlarged our knowledge of what becomes of
plant constituents in the animal body. In its present form it contains
so much of value that it will well repay all the study and time devoted
to it.


This table looks formidable enough, but when we have studied it,
column by column, I do not think it will be regarded as difficult, nor
will its contents seem dry to farmer readers. In the first column are
given the names of fodders, all of which are used in some portion of
the country for stock-feeding purposes; next to this comes a statement
of the number of analyses from which the succeeding average figures
are derived.

Water. In the laboratory the scales of the chemist are so delicate
that he can weigh a thimbleful of corn meal with a smaller proportional
error than the farmer weighs a wngon load of corn. In a small dish
on these scales he places a sample of the fodder with which he is to
\vork and determines its weight. Placing this in an oven it is dried at
a temperature of 212 F. for several hours and weighed again. The


heat lias driven off the water and the difference in the two weights
represents the water which the sample contained. The average amount
of water found in the various samples in the list is placed in the column
headed " Water." It will be seen that the proportion of water in the
different feed stuffs varies greatly. In 100 pounds of pasture grass
there are 75.3 pounds of water on an average; with roots the amount
reaches as high as 90 pounds, while for straw and grain it varies from
8 to 1C pounds of water per hundred weight. Water is the great vehicle
for transporting food both in the plant and animal, and, while of the
highest importance to both, it is so universal and abundant that we
need not further consider it at this time.

Ash. Carefully burning a sample of the fodder, the chemist deter-
mines the ash. By the table we find that in 100 pounds of pasture
grass there are 2.5 pounds ash, while in clover hay there are over 6
pounds. One hundred pounds of shelled corn contains only 1.5 pounds
of ash, while the same weight of wheat bran yields over 5 pounds. The
ash elements in plants are very important, since they enter into the
composition of all the tissues of the body in a small way, and form the
larger part of the bones. Experience shows that when the stockman
feeds his animals abundantly with a variety of nutritious foods they
are amply supplied with ash for all necessities of the body, so that as
with water this part of the plant substance need not receive special
attention when considering the constituents of feeds, though there are
a few special cases where the supply of ash is apt to be lacking, even
when the animals are seemingly well nourished.

Crude protein marks a very important group of substances in fodders,
the characteristic element of all being nitrogen . The chemist has found
that protein compounds weigh C.25 times as much as the nitrogen con-
tained ; by a complicated process he determines the weight of nitrogen
in a sample of feed, and multiplies this by 6.25, which gives the crude
protein. A considerable portion of the bones, the ligaments which hold
the bones together, the muscles which surround the bones, the tendons
which bind the muscles to the bone, and the great nervous system, as
well as the internal organs of the body, are largely composed of protein
compounds. From this we can readily understand that protein is a very
important part of stock foods, being especially needed with young, grow-
ing animals. We turn with interest to the table and note that the total
crude protein in pasture grass is 4 pounds to the hundred, while in
oats there are 11.8 pounds, in corn, 10.5 pounds, and nearly 33 pounds
in 100 of linseed meal.

Crude fiber is determined by boiling a sample of the fodder first with
a weak alkali, and then with a weak acid in order to dissolve out as
much of the substance as possible. The uudissolved portions represent
the tougher parts of the framework of the plant, usually termed cellu-
lose or crude fiber. The table shows that a large portion of rye straw
is crude fiber, while in grains like corn or wheat the amount is very


Ether extract. On another sample of the fodder the chemist places
ether, which dissolves out whatever fats and wax it contains, and this
dissolved portion is called the ether extract or crude fat. Hay and
straw contain very little fat, and still less is found in mangolds or
turnips, while corn contains considerable, and oil meal and cotton-seed
meal a relatively large amount.

Xitrogen-free extract signifies what is left of the organic matter of the
plant after deducting the preceding groups of elements. It contains
starch, sugar, dextrine, and gums.

Carbohydrates. The nitrogen-free extract and the crude fiber are
grouped together under the term carbohydrates. The leading function
of the carbohydrates is to furnish fuel for the animal body. Portions
not needed for immediate wants may be converted into fat and stored
up in the tissues awaiting future demands.

The figures given in all the columns of the table we have passed over
are derived from analysis in the laboratory, and represent the total
amount of each of the plant constituents in the several groups. Thus
far the investigation is purely a chemical one, though the grouping of
the substances has some relation to the uses of the food in the animal
system. Having learned the amount of each of the constituents in a
given fodder, the chemist proceeds to feed it to some farm animal,
usually an ox or a sheep, in order to ascertain what portion of each is
digestible. The value of gold ore is not rated by the total amount of
gold contained, but rather by that portion which can be recovered by
practical processes; so with our feeds, only those portions which can be
digested and utilized by the animal are really valuable. The results of
digestion trials are grouped in the last columns of the table under the
head ' Per cent of digestible matter," and these data have cost the
chemist and animal physiologist much patient labor; oven now the
results are crude and far from satisfactory.

Let us study this table item by item, as we did the first part. We
learn that while the total crude protein in pasture grass is 4 in 100
pounds, the digestible crude protein is 2.8 pounds in a hundredweight.
The digestible carbohydrates, the eomi>oumls of crude fiber and nitrogen-

Online LibraryUnited States. Bureau of Animal IndustrySpecial report on diseases of cattle and on cattle feeding → online text (page 51 of 56)