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increasing the production of metabolic heat [1]. For adult sheep, the lower critical temperature
is –3 °C [2]. Low temperatures can provide a risk to the welfare of sheep during transport
because of increased ventilation chilling the sheep. This paper [3] reports on an investigation
into the importance of three factors during the road transport of sheep in cold temperatures:
covering the vehicle, duration of the
transport, and feeding prior to transport on the welfare
of sixty transported 4-month-old Dorper × Mongolian female sheep in a cold climate. The
transport journeys took place on 15 and 16 January 2020. Mean maximum and mean minimum
temperatures on these two days were −13 °C/−21 °C and −11 °C/−18 °C; the humidity was 69%
and 77%, respectively. Three experiments were conducted with two treatments in each and 10
sheep in each treatment. The factors investigated in the three experiments were: enclosing the
vehicle (truck with or without a plastic cover and 1 h trip); transport duration (1 or 2 h); and pre-
feeding (feeding the sheep before loading or not, on a 2 h trip). Temperatures were low before
the transport, -17 and -13 °C.
The results from the covered vehicle study included that the sheep in the covered vehicle
had greater increases in head and ear temperatures compared to those in the open vehicle.
And that Heat shock proteins (HSP), which expression can occur after excessive temperature
change, including cold temperature change, were higher in the sheep transported in the open
vehicle. Sheep transported for 2 h increased their leg temperatures, whereas those transported
for 1 h had reduced leg temperatures. Increases in non-esterified fatty acids (NEFA) and lactate
dehydrogenase (LDH) in the blood samples during the longer transport suggested that sheep
had more muscular and metabolic activity, compromising their well-being. For two-hour
transportation compared with one-hour transportation cortisol increased significantly more.
Creatine kinase and Lactate dehydrogenase (LDH) increased significantly in the longer duration
transport, which could indicate a muscle damage effect of movement during driving. Alanine
aminotransferase (ALT) was also higher and this can indicate a change in liver function. High
concentrations of ALT could be an index of activity in the blood for the metabolic processes
involved in carbohydrate, protein, and fat conversion [4]. The rates of metabolism increase
during stressful conditions [5] and also when skeletal muscle is regularly contracting [6].
Feeding prior to transport did not affect body temperatures, but those not fed prior to transport
had reduced alanine transferase, HSP and cortisol in their blood, whereas those that were fed had
reduced NEFAs, LDH and creatine kinase. Prior feeding had no effect on the sheep temperature
indices over a two-hour transport period.
Thus, the sheep most at risk of the adverse effects of cold temperatures were those transported
in
open vehicles, those transported for a longer time, and those not fed before transport.
These problems identified in sheep in transport in cold climates, can have impacts on human
wellbeing, including loss of profit to the farmer, food security (reducing live animal transport
will reduce losses of food from animals in the current system), Ethic concerns of the general
public; customers have concerns about the well being of the animals that provide them with
food, and the affect on the ; human-animal relationship on the :stock people involved in the care
of these animals.
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