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Hairy experience
Q
The few gilts and sows that I keep
have a very thin cover of hair. This
is most apparent in the Tamworth, but
I’ve noticed the same condition on my
Large Black and cross-bred pigs too.
There’s almost a total loss of hair cover
along the sides and hind limbs. What
do you think is causing this and should I
be concerned?
JP, Isle of Lewis, Hebrides
A
The photograph you’ve supplied
illustrates the situation that you
outline perfectly. I have encountered the
same, or at least very similar, situations
year after year. If anything, the smaller
breeds of ‘pet’ pig, such as the Kune
Kune and Vietnamese, for example,
seem to be most noticeably affected.
During the summer I took particular
note and have pictures of most of the
pure breeds with variable degrees of
alopecia (hair loss). I’ve observed such
individual pigs in shows and sales as
well as on pig farms. You may think I’m
avoiding the question and in particular
what is likely to be the cause. My
conclusion is that there is more than
one factor involved which results in the
steady thinning of the hair cover.
Seasonal effects are involved.
Despite the fact that pigs rely more
on huddling together and burying
themselves in the bedding to keep
warm, their hair cover – as well as
their fat layer under the skin – also
contributes to body temperature control
(homeostasis). As a point of interest,
pig skin resembles human skin more
closely than many other species, but
has comparatively few sweat glands.
So, if the environmental temperature
rises, the production of hair will be
influenced.
A pig’s hair coat consists of bristles
which make up 60-70% plus a more
downy hair, which accounts for the
remaining 30-40%. Many stock people
will have noted pigs that are unwell or
performing poorly appear to become
‘hairy’. Also, pigs that are kept outside
often appear to have more hair cover.
The thinning and/or loss of a pig’s
hair cover may occur in combination
with skin irritation. If the pigs you
mention are rubbing on pen structures
(or anything else outside), or scratching
with their hind feet, then there’s
probably a different, irritation-triggered
cause.
The most frequent of these is
sarcoptic mange, which is caused by
a microscopic mite that burrows into
the superficial skin layers; it can also be
found in the ears. Another possibility is
the pig louse (a so-called ectoparasite).
These can be seen with the naked eye,
but they generally tend to produce less
irritation. I’m assuming that there are
no obvious signs of skin irritation
with your pigs, otherwise you’d have
mentioned it.
The causes of non-itchy loss of hair,
as listed in the veterinary texts, involve
deficiency of various microelements.
These include certain of the B vitamins
riboflavin and niacin, fatty acid
deficiency, panthothenic acid deficiency,
biotin deficiency and even vitamin A, C
and E deficiency. With this in mind, the
answer could be to focus on the supply
of a balanced feed for your adult pigs.
Almost always the compound
feed industry ensures balance with all
major and minor elements that are
known to produce pig health, including
a healthy skin. If you feed your own
components, then it’s very important
to make sure that the ration being
given is actually meeting the dietary
needs. With the arrival of winter, and
the feeding of a professionally-balanced
ration, I’d expect the hair and bristles
to redevelop.
Hair length and coverage will vary with the seasons, but hair loss can be triggered by other factors too.
Winter 2010 19