Browse through topics for Senior Secondary 2 1st, 2nd and 3rd Terms, All Weeks, All Subjects
Term: 3rd Term
Week: 4
Class: Senior Secondary School 2
Age: 16 years
Duration: 40 minutes of 2 periods each
Date:
Subject: Agriculture
Topic:- Environmental Physiology
SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to
INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source
INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures
INSTRUCTIONAL PROCEDURES
PERIOD 1-2
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PRESENTATION |
TEACHER’S ACTIVITY |
STUDENT’S ACTIVITY |
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STEP 1 INTRODUCTION |
The teacher reviews the previous lesson on fertilization, implantation, gestation and parturition |
Students pay attention |
|
STEP 2 EXPLANATION |
She defines environmental physiology She states the effects of climate change on growth, reproduction, egg and milk production |
Students pay attention and participates |
|
STEP 3 DEMONSTRATION |
She further discusses how to control heat/temperature, humidity and light |
Students pay attention and participate |
|
STEP 4 NOTE TAKING |
The teacher writes a summarized note on the board |
The students copy the note in their books |
NOTE
ENVIRONMENTAL PHYSIOLOGY
Environmental Physiology is concerned with the environment's influence on the physiological function and performance of living organisms.
EFFECTS OF CHANGES IN CLIMATE ON GROWTH
Changes in climate have some effects on the growth of farm animals.
(i) Extremes of either not or cold conditions is unfavourable and reduces the performance of farm animals.
(ii) Wind aids the spread of diseases (air borne diseases, e.g. tuberculosis) which cause retarded growth of even death of farm animals.
(iii) High rainfall leads to the multiplication of tsetse flies which transmits trypanosomiasis and such disease reduces the growth of even leads to the death of farm animals.
(iv) High temperature leads to heat stress in farm animals, e.g. cattle, poultry and pig.
(v) High relative humidity affects food intake of farm animals.
(vi) High intensity of radiation affects food intake of farm animals.
(vii) Moderate wind velocity promotes good ventilation and this enhances the normal growth of farm animals. Extremes of wind have negative impacts on the growth of animals.
EFFECTS OF CHANGES IN CLIMATE ON REPRODUCTION
Changes in climate have some effects on reproduction of farm animals.
(i) Heat stress (i.e. high temperature) causes abortion in farm animals.
(ii) High intensity of radiation causes heat stress in farm animals, this reducing their reproductive capabilities.
(iii) High relative humidity affects the reproductivity of farm animals.
(iv) High temperature leads to low rate of conception or fertilisation in farm animals.
(v) At high temperature, frequency of mating and quality and quantity of semen in breeder birds decrease.
(vi) At high temperature, fertility and hatchabilityin breeder birds decrease.
(vii) High temperature decreases ovulation in animals.
(viii) High rainfall and high humidity cause the chilling of young ones soon after parturition.
(ix) High temperature can reduce spermatogenesis of male animals.
EFFECTS OF CHANGES IN CLIMATE ON MILK PRODUCTION
Changes in climate have some effects on milk production by farm animals.
(i) High relative humidity favours the growth of disease pathogens that can reduce milk production in farm animals.
(ii) High intensity of radiation from the sun causes heat stress in animals, this reducing their milk production.
(iii) High temperature and rainfall do not favour the rearing of diary animals.
(iv) High rainfall leads to the multiplication of tsetse flies which transmit trypanosomiasis in diary cow, thereby leading to low milk production.
(v) Physiological processes are retarded at extremes of temperature leading to low milk production.
(vi) Pathogenic bacteria in milk are destroyed when milk is subjected tons high temperature of about 70°C. (pasteurisation)
EFFECTS OF CHANGES IN CLIMATE ON EGG PRODUCTION
Changes in climate have some effects on egg production in poultry birds.
(a) Temperature
(i) High temperature causes a reduction in feed intake, leading to low egg production.
(ii) It reduces spermatogenesis and libido in makes.
(iii) High temperature causes heat stress, thus reducing egg production.
(iv) It may result in death of birds, particularly chicks and layers
(v) It is necessary for incubation of eggs.
(vi) High temperature reduces hatchability of eggs
(vii) Ideal or moderate temperature leads to better egg production.
Control of Heat/ Temperature
(i) Fans or air conditioners should be introduced.
(ii) Enough windows and opening for ventilation should be provided.
(iii) Poor conductors of heat should be used as roofing sheet. Sun-reflecting sheets can also be used or the roof should be painted White. Pens should also have the ceiling boards under the roof.
(IV) Room heaters or lanterns should be used to warm buildings when it is cold.
(V)During construction, keep open parts of the buildings away directly from the solar radiation (i.e. East to West direction)
(b) Relative Humidity
(i) It is very important in incubation of eggs.
(ii) High humidity compounds heat stress.
(iii) Low humidity induces rapid water loss from the birds' body and thus increases their water intake.
(iv) High humidity causes feed to go mouldy.
Control of Humidity
(i) This can be controlled by fixing of humidifyers or open trays filled with water to increase humdity.
(ii) Free ventilation should be allowed when the humidity is high.
(iii) Spilling of water in poultry houses should be avoided to reduce humidity or dampness.
(3) Light
(i) It controls egg laying in hens.
(ii) Duration of lighting controls time spent at feeding which regulates growth and rate of feathering.
(iii) Direct light of high intensity causes street to the eyes.
(iv) Bright light makes the birds active.
Control of light
(i) In short day length, extra illumination should be provided.
(ii) A reasonable part of the walls should be made up of wire mesh or glass to promote lighting.
(iii) Windows should be covered with dark cloth to reduce light intensity.
EVALUATION: 1. Define environmental physiology
CLASSWORK: As in evaluation
CONCLUSION: The teacher commends the students positively