The Rural Voice, 2006-03, Page 20Curiosity spoiled the pork
University of Guelph researchers find that a pigs personality influences
the stress they experience in shipping and processing. Surprisingly,
curious pigs show the most problems.
By Keith Roulston
n the ongoing campaign for
consistent pork tenderness,
little immeasurables like
animal personality and on-farm
management play an important,
and only recently -discovered,
role.
Two researchers told
producers at the Centralia Swine
Research Update in Kirkton,
January 25, that new studies
show how the personality of the
pig can affect meat tenderness
after processing and how some
simple management techniques
can help reduce the losses.
The importance of the issue
was touched on by Dr. Peter
Puslow, part of a team of
University of Guelph
researchers looking into factors
causing such meat -quality -
related factors as drip -loss and
the colour of meat in loins. If
drip loss could be reduced by
one per cent, he said, it would
mean an extra $26.5 million in
the pockets of Ontario's pork
industry.
The study involved following
pigs shipped from 20
commercial producers, as well
as two groups of pigs produced
at the university's own Arkell
research farm ( a total of 624
pigs), through processing at That curious pig in the lead might produce tough meat
Conestoga Packers. The study when processed, University of Guelph research shows.
went all the way from the Producers can take steps to manage the incidence of
subjective in recording the stress in handling pigs.
behavioural activities of the pigs during handling, to the
precision of pH testing of the meat to tenderness tests using
precise shear -force measuring machinery in the laboratory.
Blood testing measured levels of blood glucose and lactate.
Genetic testing was done on the pigs that presented
extremes within the sample to see if genetic markers could
be identified.
The results showed extremes: for instance drip loss
ranged from 2.69 to 12.54 in loin measurements (not good
news for attempts to hit the U.S. National Pork Board goal
of 2.5 per cent drip loss). Similarly tenderness ranged from
16 THE RURAL VOICE
a shear force reading of 2.08
for the loin to a high
(tougher meat) of 7.66.
The early evidence in the
three year study that began
in 2005, is that stress plays a
big role in the quality of the
meat. Dr. Tina Widowski,
another member of the
research team, explained that
fear or stress results in a
surge of adrenaline which
can change the pH and
temperature of the muscle at
slaughter, which in turn
affects the colour and water -
holding capacity of the meat.
As well, she said,
prolonged stress from
fatigue or fighting can affect
meat quality by depleting the
energy stores necessary for
the biochemical changes that
ensure a good quality
product.
"Reducing stress all the
way from that farm to the
point of slaughter is
important for ensuring both
good animal welfare and
meat quality," Dr. Widowski
said.
A lot of attention has been
given in recent years to
training handlers of pigs'and
redesigning handling
facilities at processing plants
to reduce stress on animals
but even in a well-designed
facility, skilled handlers often find that some pigs are
simply harder to move than others, says Dr. Widowski. The
result is more stress on the pigs (not to mention the
handlers).
For some of the pigs, experience of being moved
reduces the stress level. University researchers tried to
measure the experience factor by observing two farms and
following the pigs from those farms through the packing
plant. Pens on the two farms were "walked" once, twice of
three times a week during the last 12 weeks, with some
pens not walked at all. To "walk" the pens, the stockperson
i
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