Agriculture Reference
In-Depth Information
136 km in Zimbabwe and sustaining a total live weight
loss of 12.88% (1.7% tissue loss) regained much of the
tissue loss in 24 hours after resting and drinking water,
but not eating. Even after rail transport for 4 days in
South Africa during mid-summer, cattle recovered rap-
idly if rested with food and water. In the same country,
the resting of adult Merino sheep for 24 hours with feed
and water after rail transport for more than 3 days had a
beneficial effect on carcase yield. Much of the weight loss
in pigs during transport is believed to be due to loss of
water, so it is important for these animals to have access
to water before and after transport. However, it has been
shown in Poland that resting pigs for 24 hours after
transport does not help them to recover unless they are
fed, and even feeding restores the condition of the mus-
cles and liver but not the loss of carcase weight.
In the case of
farmed deer
, it was found that after a
journey of 160 km lasting 3 hours, a group of 5 hinds lost
1.09% of their pre-transport weight when weighed
within 90 minutes of slaughter. Three similar groups
held in a lairage with
ad libitum
food and water for 3,
6 and 18 hours lost 1.93, 3.19 and 6.22% of their body
weight, respectively. Although live weight loss increased
with lairage time, hot carcase weight was unaffected
(Grigor
et al.
, 1997).
of 149.6 kg live weight loses 4 kg during its first day of travel
and 1.8 kg on the second day; and a bullock weighing 610 kg
will lose 30-40 kg during the first day of travel but only
5-6 kg on subsequent days. Studies indicate that it takes
5 days for cattle to recover this loss.
However, it should be pointed out that there is evi-
dence that feeding pigs up to the time of collection leads
to higher transport mortality (Warriss 1995) and that
pigs as monogastrics can suffer from travel sickness due
to vehicle vibration which can be accentuated by poor
roads and poor driving.
Studies in New Zealand indicate that in lambs the loss
in carcase weight over the first 24 hours in transit is
small. However, if the period without food extends
beyond 24 hours, the loss of carcase weight becomes sig-
nificant, amounting to approximately 0.5 kg/animal/day.
With bacon pigs, the loss in actual carcase weight is
about 0.9 kg for every day of their journey, and it is prob-
able that both muscular and fatty tissues are affected,
with an abnormal loss of water from the muscular tis-
sues. The effect of overexertion, excitement and strange
surroundings on pigs during transit may also cause a loss
of 6-7% in the weight of the liver.
The amount of weight loss in pigs increases with a rise
in temperature and decrease in relative humidity. When
Large White pigs were sprayed with fine sprays of cold
water in an uncovered lorry which travelled 80 km, the
weight loss was reduced by 50%. Pigs also lose weight
when transported during very cold weather. Relative
humidity and temperature also appear to be involved in
the development of dark, firm and dry (DFD) meat in
cattle, the incidence of which, at least in Britain, seems to
be greatest during cold, muggy days of November.
In the United States, cattle transported by rail are stated
to lose 1.48% of carcase weight on journeys of up to
161 km and 2.1% on journeys of 402-482 km. Tissue
shrinkage begins during the early part of a journey,
continues at a relatively uniform rate for 90 hours and
then tends to diminish. Some shrinkage occurs even if
animals receive food and water during transport but is
less if these are provided during long journeys. In the past,
cattle from the northern parts of Australia lost so much
weight on their long overland trek to the slaughterhouses
that they were placed on pastures for up to a year to regain
the weight and quality needed to meet export demands.
From work in Australia, Thompson
et al.
(1987)
report that in a 35 kg lamb of fat score 3, the losses of hot
carcase weight were in the order of 4 and 6% after 24 and
48 hours' fasting, respectively, compared to mean losses
in 27-32 kg lambs of 2 and 4%.
In relation to
weight loss
suffered during transit, it is
possible in many cases to restore some, if not all, of this
loss with adequate rest. Cattle transported by rail for
Transport mortality
Death during transport is a measurement indicating a
severe level of distress in transit. A mortality rate above
zero must always be considered unacceptable from a
welfare perspective. All those involved in the transport
of animals must strive to achieve this ideal goal, espe-
cially faced with increased consumer awareness of the
ethics of food, animal production and transport.
Deaths occur in all classes of livestock during trans-
portation, although in most countries the incidence is
less than 0.5%. In a survey of mortality rates in 2.9 mil-
lion slaughter pigs throughout England, Warriss and
Brown (1994) indicated that 0.061% died during transit,
while 0.011% died in the lairage. Kephart, Harper and
Raines (2010) reported a mortality rate of 0.06% in pigs
irrespective of journey length, compared with a study by
Abbott
et al.
(1995), who found a death rate during
transport of 0.11%. These figures are very similar to
those reported in the 1970s by Smith and Allen (1976),
suggesting that the position has remained fairly stable
over that 40-year period.
Extremes of
temperature
, especially heat, can be
responsible for many losses in livestock, particularly
pigs. At 32°C, death rates are twice that recorded at 16°C.
More animals die when it is hotter, particularly above
16°C (Allen and Smith, 1974), and when animals are left
in a stationary vehicle. It has been noted that in summer,
