Classwork Series and Exercises {Agricultural Science – SS2}: Environmental Physiology

Environmental Physiology

Agricultural Science, SS 2 Week: 1

Topic: Environmental Physiology

Definition of Environmental Physiology

This can be defined as effects of the environment on the growth and performance of farm animals. Normal growth and performance are enhanced when climatic factors like temperature, rainfall, wind, relative humidity, sunlight etc. are moderate.

Effects of Changes in Climate on Growth

1. High intensity of radiation affect food intake of farm animals.
2. High relative humidity leads to heat stress in farm animals e.g. cattle, poultry, pig, etc.
3. Extreme low temperature leads to retarded growth or even death of chicks.
4. At high temperatures also, feather coverage in chicks are poorly developed and this may lead to pecking.
5. Wind aids the spread of air borne disease e.g. tuberculosis.
6. High rainfall leads to the multiplication of tsetse-flies which transmits trypanosomiasis.

Effects of Changes in Climate on Reproduction

1. Heat stress causes abortion in farm animals.
2. High temperature decreases ovulation in animals.
3. At high temperature, fertility and hatch-ability in breeder birds reduces.
4. High temperature leads to low rate of conception or fertilization in farm animals.
5. Light controls sexual maturity.

Effects of Changes in Climate on Milk Production

1. High temperature reduces the rate of milk production in farm animals.
2. High temperature and rainfall do not favour the rearing of daily animals.
3. High relative humidity favours the growth of disease pathogens that can reduce milk production in farm animals.

Effects of Changes in Climate on Egg Production

The effects include;

1. Temperature
2.   It reduces spermatogenesis and libido in males.
3. High temperature lower egg production.
4. iii.   High temperature reduces hatch-ability of eggs.
5. Egg storage period is reduced under high temperature.
6. High temperature causes a reduction in feed intake while a low temperature encourages more feed intake.

Control of Heat/Temperature

1. Fans or air conditions should be introduced.
2. Enough windows or opening for ventilation should be provided.
3. Vents should be provided at the roof tops.
4. Room heater or lanterns should be used to warm the building when it is cold.
5. Relative Humidity
6. It is very important in incubation of egg.
7. High humidity compounds heat stress.
8. High humidity causes feed to go moldy.
9. It encourages the spread of disease.

Control of Humidity

1. Free ventilation should be allowed when the humidity band is high.
2. Spilling of water in poultry houses should be avoided.
3. Humidifiers or open trays filled with water should be fixed to increase humidity.

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