DENTITION AND AGE OF PIGS
Although the majority of pig sellers may claim to be, and may be able to
substantiate the claim to be, equally as honest as the majority of
others in trade, yet there may be a small minority who are apt to
attempt to palm off pigs as being older than they really are. It is most
annoying when you are anxious to purchase pigs of say six or seven
months old which are quite ready to be quickly fattened, to have pigs of
four or five months old which continue to make growth instead of flesh,
so that they are not ready for killing until two or three months after
they are required for conversion into bacon.
Although the object of the Council of the Smithfield Club is to prevent
fraud of a different character, i.e. the exhibition in classes limited
to certain ages of pigs of an age greater than that given on the entry
form, yet the following table showing the normal state of the dentition
of pigs at certain fixed ages will enable purchasers to discover whether
or not the seller has attempted to deceive him. It may at once be
admitted that there will be a limited number of cases in which the state
of dentition of pigs is abnormal, but after examining the teeth of some
thousands of pigs during the past sixty years, we have no hesitation in
asserting that more than half, at least, of the variations from the
normal are allayed dentition. It is claimed that a man of experience is
quite able to arrive at the approximate age of a pig by its development
and appearance; some few persons may have that instinctive knowledge
more or less fully developed, but this examination of the state of
dentition is of the greatest possible assistance in arriving at the
actual age of the pig, particularly desirable as it is in case of a
difference of opinion between buyer and seller.
The following are the conditions of the state of dentition to which all
pigs have to conform ere they are allowed to compete for the prizes
offered by the Smithfield Club at their annual shows:--
"Pigs having their corner permanent incisors cut will be considered as
exceeding six months.
"Pigs having their permanent tusks more than half up will be considered
as exceeding nine months.
"Pigs having their central permanent incisors up, and any of the first
three permanent molars cut, will be considered as exceeding twelve
months.
"Pigs having their lateral temporary incisors shed, and the permanents
appearing will be considered as exceeding fifteen months.
"Pigs having their lateral permanent incisors fully up will be
considered as exceeding eighteen months."
As the majority of the pigs bought of dealers by amateurs are young pigs
it may be advisable to state that a pig of the age of eight weeks old
should have its two central incisors fully grown. A pig three months
old should have all four temporary incisors cut, the two outside ones
being more than half as long as the two central incisors.
As the first set of the teeth of a pig like that of a child are merely
temporary, and as these give place at fairly definite ages of the owner
to permanent ones, it may be well to endeavour to describe as clearly as
possible the position and appearance of the temporaries as compared with
the permanents. The pig is one of the few animals which is possessed of
teeth at its birth; these number eight, two on each side of the upper
and lower jaw. It has been suggested that these early teeth are provided
to assist the pigling to grasp firmly the sow's teat when in the act of
sucking. These eight teeth vary somewhat in length; those pigs which are
carried by the sow beyond the usual period of sixteen weeks frequently
have longer and even sharper teeth than those of pigs which are born at
the usual time. These longer teeth are also sometimes of a dark colour.
This is doubtless the origin of the remark commonly made by
old-fashioned pigmen that "pigs born with black teeth never do well."
This might have been so prior to the discovery that the breaking off the
sharp teeth of the newly born pigs frequently saved trouble, and often
the life of the little pigs. Pigs whose teeth are discoloured at birth
are usually more robust rather than the reverse, since the sow carrying
them beyond the allotted time is invariably in a vigorous state of
health, and her pigs consequently more fully developed.
When the pig is about a month old, the two central incisors are cut in
each jaw, these are two of the four front teeth in each jaw of the pig
at a subsequent age. Two temporary molars are also cut on each side of
the jaw above and below, with the first temporary molar in each place
ready to come through the gum.
At two months the temporary central incisors are fully developed, and
the two lateral temporary incisors can be seen in the gums, if they are
not already through. All three temporary molars are now about level.
When the pig is about three months old its temporary teeth are all in
position, the temporary lateral incisors are through, and nearly as long
as the temporary central incisors. Owing to the lengthening of the jaws
the two temporary corner teeth which were present at birth will have
become further apart. When the pig is about five months, the fourth
molar in either jaw shows itself in the gums, then at six months the
wolf teeth show between the tusks and the premolars, and the fourth
molar is nearly level with the first premolar. The corner incisors and
the tusks usually disappear, and are replaced by permanents when the pig
is nine months old. The second permanent molar also shows itself. At
twelve months the two central temporary incisors give place to the
permanents; these last are more square in form than the temporaries, and
are thus easily distinguished. The three temporary molars will also be
ready for displacement by three permanents. These last will be level
with the other permanent molars when the pig is fifteen months. The two
lateral incisors will also have given place to permanents. At eighteen
months the third permanent molars will be coming through, and at the age
of twenty months the pig's teeth are fully developed.