HOG SLAUGHTERING
HISTORICAL -- INVESTMENT -- HOG YARDING -- HOG DRESSING -- HOISTING
-- STICKING -- NECK WASHING -- SCALDING -- SCRAPING MACHINES -- HAND
SCRAPING -- CLEANING BODIES -- HAM FACING AND CUTTING -- LEAF LARD
-- SPLITTING -- WASHING -- DRYING -- CARE IN CHILL ROOMS -- OPEN AIR
HANGING -- CHILLING NECESSITIES -- SHRINKAGE IN CHILL ROOMS -- HOG
BY-PRODUCTS -- HEADS -- PLUCKS -- PAUNCHES -- ENTRAIL FAT.
=Historical.=--In no department of the industry has the progress been
so extensive as in pork packing. Only a few years ago, comparatively,
it was impossible to kill hogs for packing purposes, except during the
winter season, and the various packing plants located throughout the
country worked during the winter months in their crude way, packing as
many hogs as conditions would permit, turning out the cured meat in the
spring, in inferior condition.
Under the conditions then existing there was little of the hog sold
fresh, for being killed as they were, in isolated places, there was
little opportunity to make it available for general consumption,
consequently fresh pork was sold only in the immediate vicinity of the
slaughtering place and it was necessary to cure the balance. Under
present methods, fresh pork product is shipped to England and delivered
in good condition to the consumer.
The important step in the evolution of “all-the-year packing” from
“winter packing” was the introduction of the refrigerating machine,
and in packing houses today little or no regard is paid to the outside
temperature. Another great advantage is the transportation facilities
now available. When killing hogs in large quantities the fresh pork
product is sold fresh and consumed as such, and a much greater revenue
is derived than when salted as formerly, and sold as cured meats. With
the present facilities for distribution the public can buy fresh pork
at any time of the year, while a few years ago it was impossible to
obtain it at any price during warmer seasons, unless in the immediate
neighborhood of the place where the animals were slaughtered.
[Illustration: FIG. 97.--UNLOADING HOGS FROM CAR.]
=Investment.=--The investment capital used in pork packing is
much greater than for beef, for in slaughtering cattle there is
comparatively little left that requires storage, but in slaughtering
hogs fully seventy per cent of the carcass goes into the curing
department, to stay from thirty to ninety days; consequently a much
larger and more expensive set of buildings is required than for
slaughtering cattle. For instance, in the matter of chill room it is
customary to require cooler space for twice or three times the killing
capacity and storage area equal to five times the hog hanging area;
in other words, if a plant was to be built to kill a thousand hogs a
day there should be hanging capacity for 2,500 and five times the floor
area should be sufficient for curing the product, providing it is sold
promptly as cured. If it is to be carried for any length of time a
greater ratio than five to one should be used. This, of course, does
not refer to any of the auxiliary departments of the plant but only to
the cold storage and chill room department.
=Hog Yarding.=--Hogs should be rested in closed covered pens arranged
for summer ventilation, and winter warmth. It is essential that they be
well rested and cooled before they are slaughtered. To rest twenty-four
hours is by no means detrimental. In driving provide the driver with a
flat canvass belt attached to a short wooden handle so that the hogs
are not abused by clubbing. Keep plenty of water in the troughs and
keep pens clean.
More care should be used in handling hogs than any other live stock, as
hogs are more easily injured. Special pens should be provided for their
reception. Hogs should never be killed until they are thoroughly rested
and in normal condition. In the summer weather they should be sprinkled.
=Hog Dressing.=--The principal points for attention in hog slaughtering
are briefly referred to under the following headings.
=Hoisting.=--When passing to the catch pens for hoisting, the pen
floor should be arranged with raised or corrugated surfaces to avoid
the possibility of its becoming slippery and the hogs “spreading” as
a result. The hogs should be headed in such a direction that when the
shackle is attached to the wheel the hind quarter of the hogs are the
first to move upward, without unduly twisting or wrenching the hog.
The transfer to the sticking rail should be done smoothly and without
jerking.
A hoist, shown in Fig. 102, is often used; it is not only a very useful
device but it is also economical from the fact that it does not jar or
injure the hogs when hung up, as is often the case with an ordinary
hand hoist. This particular machine is adapted for small slaughter
houses rather than where business is done on a large scale, in which
case a double machine will be found almost indispensable.
[Illustration: FIG. 98.--DIAGRAM OF COVERED PEN FOR HOGS AND SHEEP WITH
DETAIL OF CONSTRUCTION.]
[Illustration: FIG. 99.--ELEVATION FOR COVERED PEN FOR HOGS AND SHEEP
WITH DETAIL OF FENCE AND GATE.]
[Illustration: FIG. 100.--HOGS RESTING AND COOLING OFF BEFORE BEING
TAKEN TO THE SLAUGHTERING HOIST.]
=Sticking.=--Make a large and free opening. To insert a knife and make
a slit only large enough to admit it is insufficient. The sticker’s
knife should be sharpened on both front and back and when it is
withdrawn, a long smooth opening four or five inches long should
be made. It is far better, as hogs bleed more freely and die much
sooner. Be careful to see that the veins and arteries are cut, and at
the same time do not cut into the shoulder, as in that instance the
blood settles there and it becomes necessary to trim, resulting in
considerable loss. See that sufficient hogs are kept on the rail so
that they may bleed out well before dropping in the tub. The sticker
should keep close to the hanging off--sticking the hogs immediately
upon hanging.
[Illustration: FIG. 101.--HOISTING HOGS ON A HURFORD REVOLVING WHEEL.]
=Neck Washing.=--Where space is available a washing spray of cold water
to drench the forequarters, head and feet, is a great advantage, as
the washing of the blood enables better scalding and makes for cleaner
hands and feet.
=Scalding.=--See that the tub is long enough to permit carrying a
comparatively low temperature and a good soaking of the hogs. This will
assist very materially in the removal of the hair, either by hand or by
machine. The scalding water should be alkaline, by the use of potash
or lime. It should be kept at an even temperature and the hogs put in
systematically.
[Illustration: FIG. 102.--HURFORD SMALL HOG HOIST.]
=Scraping Machines.=--There are a variety of mechanical scrapers on
the market, and the output of goods per hour is perhaps the guide
in selecting a scraper for a large output. All things considered, a
vertical type barrel equipment, with scraping arms, delivering the
hog into a horizontal beater type would appear as the most efficient
and the less expensive for up-keep. The up-keep on a hog scraper is a
matter of no small figure and is worthy of careful consideration in the
selection of the equipment. In small plants, the choice is a matter of
personal preference, the beater types being probably the most popular.
=Hand Scraping.=--Hair should be scraped out when possible in
preference to cutting off by shaving. A bench is provided following the
scraper for the finishing touches in this respect.
[Illustration: FIG. 103--STICKING AND BLEEDING HOGS.]
=Body Cleaning.=--A most important feature in dressing hogs is the
matter of getting the hair off, the skin cleaned and washed before
opening the hog. Inspection requirements as to cleanliness practically
demand this, and it is a proper method of dressing.
=Ham Facing and Cutting.=--In ham facing care should be used to see
that the workmen cut off the fat down to the lean meat, and at the same
time do not cut the striffen. In opening the hog it is requisite that
the opening cut should be a straight line from the stickers cut to the
bung. The breast splitting and opening over breast bone is made so as
to equally divide the sides and avoid trimming when cutting hogs; the
intestines are removed without cutting or breaking.
FIG. 104.--HOG SCALDING.
=Leaf Lard.=--Pulling the leaf lard just before the splitting, should
be done with care in order that the leaves may be pulled clean.
If this operation is performed in an indifferent manner, a considerable
amount of the leaf lard will be left in the carcasses and it is
afterward scraped out. Lard left after pulling the leaf, should be
scraped out, as it is often worth more as lard than if left as meat.
Its presence greatly disfigures the meat.
=Splitting.=--This should be done carefully and accurately through the
backbone. A wide blade chopper is by all means preferable.
=Washing.=--The hog when once cleaned, and after eviscerating and
before splitting or pulling the leaf lard, should not be washed further
unless it be on the neck, since water on split backs is detrimental to
the keeping quality of pork loins.
=Drying.=--Few appreciate the value and importance of “skin drying”
hogs by dry-shaving and dry-scraping the surface. The advantage to
refrigerating more than overcomes the initial cost of the labor
necessary.
[Illustration: FIG. 105.--HOG SCRAPING GANG AT WORK.]
=Care in Chill Room.=--It is in this particular part of the house
that the most careful and minute attention to details is necessary
in order to turn out meats in the best marketable condition, as only
a few degree deviation in temperatures from carefully set rules in
the handling of chill rooms, shows excess per cent of sour meat found
thirty to sixty days afterward, when the meats are brought from the
curing cellar. This, therefore, is a department that should receive
the most careful attention. A wrong start here can never be righted
afterward. The rule for operation is previously given under another
chapter. (See Chapter on Coolers).
[Illustration: FIG. 106.--CLEANING HOG CARCASSES.]
=Open Air Hanging.=--It was formerly considered a necessity to have
an open-air hanging room where hogs could dry after slaughtering,
in many cases allowing them to hang over night; the object being to
save refrigeration. It is the common opinion that the economy thus
obtained is anything but economy. Past experience has proved that there
are certain conditions which must be adhered to closely in the safe
handling and curing of pork products, and proper temperatures are among
the most important of these. It is very rare that these temperatures
prevail in the outside atmosphere, and hogs that are left on hanging
floor over night are either insufficiently chilled or over-chilled.
Many packers feel it advantageous, however, to run hogs into a hanging
room, allowing them to dry out for one or two hours prior to putting
them in the chill room. While this has no deteriorating effect on the
product, the expense of handling them and the cost of labor incurred is
about equal to the saving in refrigeration, if they are put directly
into the chill room.
[Illustration: FIG. 107.--SCRAPING LEAF LARD.]
=Chilling Necessities.=--The essential feature in a chill room is
that it be properly constructed and have sufficient refrigeration so
that the temperatures can be controlled precisely as desired. It is
advisable that the coolers be partitioned into tunnels. Into this the
hogs are run as fast as killed, providing that the temperature is not
run up too high. If the temperature goes above 45° F., the carcasses
should be run into another tunnel and placed in the first one as the
temperature goes down.
When the carcasses are to be cut after being forty-eight hours in
the chill room, the cooler should be brought down gradually to a
temperature of 28° F. If they are to be cut when seventy-two hours old,
which from the author’s experience is preferable, the cooler should
be brought down gradually to a temperature of 30° F. With a cooler
properly equipped, and a careful attendant, these instructions can be
carried out in detail, and when thus followed the safe curing of the
product will be found to be practically assured.
While there are other matters which need careful attention, if the
chilling is not done properly, the rest of the operation will never
save the product. The cooler should at all times be kept dry and clean
with dry sawdust on the floor, to absorb drippings, clots of blood,
etc., from the carcasses; whereas, if the drippings are allowed to
remain on the floor they soon become soured and a menace to the product.
=Shrinkage in Chill Rooms.=--The question is often raised as to how
much hogs shrink in the cooler from dressed warm weight to chilled
weight, and many people figure this shrinkage represents a loss. It
is a variable quantity depending upon conditions such as the dryness
of the hogs, the quantity of the air circulation, its temperature and
other agents. If the hogs be sold whole plant weights it represents a
loss, but no cooler can be controlled to prevent shrinkage if it be
working properly. Aside from this quite a proportion of the hog is
passed to curing rooms for treatment in salt or pickle and the original
inherent moisture is hardly a traceable factor here and also the
shrinkage in that portion rendered into lard is immaterial, while the
portion shipped as fresh pork must be well dried out to arrive in good
condition upon shipment.
The following figures give an idea of the actual shrinkage of hogs
placed directly in the coolers. It will be noted the tests were made
on light hogs used for shipping purposes. The percentage of shrinkage
would not be as great on heavier carcasses:
=TEST NO. 1 ON SHRINKAGE OF HOGS IN COOLER.=
=Forty-five hogs weighed in cooler direct from killing floor--Warm
weight, 6,892 pounds; average, 153 pounds; temperature of cooler, 51°
to 48° F.=
=Weight after hanging in cooler forty-eight hours, 6,682 pounds;
shrinkage of 210 pounds or 3.04 per cent; temperature of cooler, 35°
to 36° F.=
=Weight after hanging cooler seventy-two hours, 6,570 pounds;
shrinkage of 322 pounds or 4.67 per cent; temperature of cooler, 31°
to 32° F.=
=Weight after hanging in cooler ninety-four and one-half hours, 6,552
pounds; shrinkage of 340 pounds or 4.93 per cent; temperature of
cooler, 32° F.=
=TEST NO. 2.=
=Forty-five hogs weighed into cooler direct from killing floor--Warm
weight, 6,970 pounds; average, 155 pounds; temperature of cooler, 54°
F.=
=Weight after hanging in cooler forty-six hours, 6,660 pounds;
shrinkage of 310 pounds or 4.45 per cent; temperature of cooler, 36°
F.=
=Weight after hanging in cooler seventy-two hours, 6,623 pounds;
shrinkage, 347 pounds or 4.97 per cent; temperature of cooler, 32° F.=
=Weight after hanging in cooler ninety-four hours, 6,613 pounds;
shrinkage, 357 pounds or 5.12 per cent; temperature or cooler, 32° F.=
=Hog By-Products.=--These consist of the heads, plucks and entrails,
and so much ingenuity is being used to make commercial products
thereof, that nearly as much labor is expended upon these parts as upon
the dressing of the hog.
=Heads.=--The heads are best made free from hair before severing from
the carcass. If the loose hair is properly removed before the head is
dropped, there is far less likelihood of hair coming in contact with
cheek meat and tongues, from which parts it is difficult to hand pick.
The heads cleaned, they are skinned, the tongue is taken out, cheek
meat cut off, jaws pulled, brains removed from skulls, skull frame cut
into, to separate the teeth section and upper part of skull, cleansed
of lithoids; snouts and ears are separated from face pieces and
prepared for food products.
=Plucks.=--Plucks are separated into livers, lungs and hearts. The
hearts are used as sausage meat. The livers are selected for quality
and many sold at retail. Defective livers are used for meat meal or
digester tankage.
=Hog Paunches.=--Thoroughly clean, strip from fat, remove lining for
sale to pepsin factories. Hog pouches are used for head cheese stuffing
or cleaned like tripe for sheep sausage.
=Entrail Fats.=--All entrail fats are satisfactory for use in prime
steam lard if properly cleaned.