بسم الله الرحمن الرحیم
Final Exam
ANPR 592 : ANIMALS OF ARID ZONES
Answer all of these questions:
Q1.
It is an hour after sunrise on a windless, cloudless day in AlKharj (August). The air
temperature (T
a) is rising, but several degrees below the upper critical temperature for
your heifer. She still half-immersed in a water hole, where she has been since sunset of
the previous day. Her core body temperature (monitored via telemetry) was 38.0 (3
hours earlier) and is now 39.2
oC.
a)What is the major avenue for heat transfer from this animal under these
conditions?
Two)
Is she in thermal balance? Is it necessary to make additional
measurements to determine this balance?
Three)
Should we attempt to give her several tablets of bovine aspirin to
reduce her temperature? What would be the result?
Q2.
Both negative- and positive-feedback systems are found in all mammals. Give
examples of each system and describe the difference between the 2 feedbacks, using
your examples. Why is the negative-feedback the predominant form of physiological
control?
Q3.
Two experiments were conducted during summer (35oC) to study the
effect of drinking cold water on dairy cattle performance. One experiment was done at
Alkharj and the other was at alkhobar. The water temperature was 10
oC. Rectal
temperature and respiration rate were recorded during the experiment.
Is there any difference between these two studies, explain in details.
Q4. Discuss the followings briefly and define each one of them:
1-Zone of thermoneutrality
2-
Zone of thermal comfort
3-
Hyperthermy
4-
Zone of survival
5-
Zone of homeothermy
Q5.
Use the Water- and minerals balance as an example of the control system.
Q6.
Why will a Holstein cow with potential to produce 50 kg/day in Canada only
produce 10 kg in a tropical hot humid climate. Why will this cow produce possibly
35kg/day in Alkharj.
Q7.
Environmental heat sufficient to elevate body temperature of a cow in estrus will
reduce the conception rate- if it is embryo mortality- present the several theories to
describe why the embryo may die in a stressfully hot environment.