Page 69 - Agriculture_Form_Three

Agriculture for Secondary Schools

This requires a sturdy holder for the bucket. Likewise, the habit of suckling each
other is a problem in dairy calves. The problem can be reduced by making the calves
suckle harder and longer by using a rubber teat rather than a bucket and by giving
them access to dry feed. Assuming inter-suckling is not a problem; a group pen for
calves is more natural than individual pens and it helps to ensure normal activity
and resting.

Sheep are vigilant, tight flock and respond to disturbance by fleeing. When designing
handling facilities, these characteristics should be taken into account. A race should
be straight, level, fairly wide, without blind ends, and preferably have close-boarded
sides of which sheep will be appearing in a queue; one sheep followed by another
sheep. Those at the back should be able to see the sheep leading the queue, but the
sheep leading the queue should not see those sheep behind it. If the leading sheep
can turn back, there is a possibility that the rest of other sheep will stop the move and
turn around thus disturbing the handling activities. Sheep move best from dark into
light areas and dislike reflections, abrupt changes in light contrast and light shining
through slats, grates or holes. Therefore, handling facilities should be examined
from the height of the sheep’s eye level rather than the human to detect flaws in the
design.

Housing in relation to livestock environmental requirements

Livestock housing design is mainly concerned with the physical environment, in
particular climatic and mechanical factors. However, all other factors should also
be considered in order to create a good layout where healthy and high yielding
animals can be provided with correct feeding. The livestock housing should also be
designed in a way that enables animals to be easily handled and can produce without
stress or suffering physical harm. For example, beef cattle make their best gains at
temperatures below 25 °C. Pigs require a change in ambient temperature as they
age and grow and, like cattle, they show a decreased feed intake when under heat
stress. Piglets survive and develop best at 30 - 32 °C initially followed by a gradual
reduction to 20 °C over the first three weeks. Growing pigs (30 - 65 kg) make good
gains in the temperature range of 10 - 25 °C with 24 °C being optimum. The optimal
ambient temperature for pigs weighing 75 - 120 kg is 15 °C. Breeding sows do
well at 15 °C but suffer badly at 25 °C and above since they do not sweat when hot.
Reproduction rates fall under heat stress and sows are more likely to trample their
piglets in the discomfort of hot weather. Housing pigs has therefore to adhere to
provision of such favourable temperatures.

Sheep can tolerate a wide range of temperatures but should be protected from wind
and rain. However, a long period of high ambient temperatures inhibits reproduction.
Heat stress also reduces lambing rate, decreases the incidence of twinning, and

Student’s Book Form Three
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AGRICULTURE FORM 3 9.11.2022.indd 58
AGRICULTURE FORM 3 9.11.2022.indd 58 10/01/2025 12:31