ANIMAL IMPROVEMENT

Subject:

Agricultural Science

Class:

SS 3

Term:

First Term / 1st Term

Week:

Week 9

Topic:

ANIMAL IMPROVEMENT

Previous Knowledge: The pupils have previous knowledge of

  FISH HARVESTING 

that was taught in their previous lesson.

Behavioural  Objectives : At the end of the lesson, learners will be able to

• Say the meaning of animal improvement
• List the objectives of Animal improvement
• Write out the process/method of animal improvement

Instructional Materials 

• Wall charts
• Online Resource
• Textbooks
• Laptop
• Crop samples
• Pictures that are related to the subject matter
• Flash cards
• www.edudelighttutors.com

Methods of Teaching 

• Role modelling
• Questions and Answers
• Explanation
• Discussion
• Recitation
• Imitation
• Story Telling
• Dramatization

WEEK NINE 

MEANING OF ANIMAL IMPROVEMENT 

Animal improvement refers to the ways of developing and breeding only those animals that show the greatest merit under consideration such as good feed conversion, growth rate, disease resistance, egg size, etc. It also involves the upgrading of existing (local) breeds as a result of some undesirable characteristics which they possess.

AIMS OF ANIMAL IMPROVEMENT

1. To produce animals that can give high yield or products in form of meat, egg, milk etc.
2. To produce animals that can provide high quality of products such as yolk size, shell hardness etc.
3. To produce animals with high feed conversion efficiency.
4. To produce animals with high growth rate.
5. To produce animals with early maturity.
6. To produce animals which can adapt to climatic/environmental conditions.
7. To produce animals that are resistant to parasites and diseases.

PROCESS/METHODS OF ANIMAL IMPROVEMENT

There are three methods or processes of animal improvement. These are;

1. Introduction
2. Selection
3. Breeding

INTRODUCTION: Introduction is the bringing into the farm or a country, high quality breeds of livestock with a high productive capacity and other good desirable characteristics from another farm or country. Before the introduction of such animal from another country (exotic breeds), one must be sure breeds possess higher quality characteristics than the local breeds

Advantages of Introduction

1. Breeds which are not originally present in the home country are introduced
2. It enhances greater productivity
3. It leads to the absence of pests and diseases
4. Breeds may perform better in terms of quality and quantity, if it is able to adapt to local environment.

Disadvantages of introduction

1. It may introduce new disease(s) to the new area.
2. It may introduce new pet(s) to the area.
3. It may have the problem of adaptation to the new area.
4. It may not perform maximally

SELECTION: Selection is the process of picking or selecting from a mixed population, those animals with breeding value as parents. Selection is undertaken to maximize genetic gain.

Selection is grouped into two main classes 

1. Natural selection: This is the ability of individual animal to survive unfavourable environmental weather conditions and reproduce. Those that are unable to survive die off.
2. Artificial selection: This selection is done by man using his intelligence and influence to select and mate animals in order to increase the number of animals.

There are four types of artificial selection:

1. Mass selection
2. Progeny selection
3. Family selection
4. Pedigree selection

Advantages of selection

1. It ensures that only the best naturally available animal is selected
2. Animals with desirable characteristics are selected.
3. Animals from the best breeds are bred for distribution.
4. Animals with undesirable characteristics are dejected and rejected.
5. Selection reduces the spread of diseases.
6. It also reduces the spread of parasites associated with breeding stocks.

Disadvantages of selection

1. Selection is tedious and time consuming.
2. It is very costly in terms of time and money.
3. It requires expertise which may not be readily available.
4. It brings about elimination or exclusion of some desirable trait of some parents stocks.
5. No new desirable characteristics are introduced.

BREEDING: Breeding involves the development of animals by transferring inherited qualities from parents to offspring. This achieved through mating.

Types of Breeding

1. In-breeding: this involves the mating of more closely related animals than the average of the population from which they come e.g. the mating of father to daughter, son to mother or brother to sister.
2. Line-breeding: It is closely related or similar to in-breeding. It involves the mating of not too closely related animals e.g. mating between cousins.
3. Cross breeding: This is the mating of proven quality animals from different breeds. It may lead ta an increase in hybrid viguor e.g. the cross between muturu (resistance to trypanosomiasis) and white Fulani (less resistant to disease) to produce a hybrid which combines two good qualities of two breeds.
4. Out breeding: This is the mating of unrelated individual animals within the same breed. 

Out breeding is the opposite of in-breeding. It produces offspring with greater vigour and productivity.

Advantages of Breeding

1. The crossing or mating of superior animals from two different breeds produce an offspring that is superior to the average of either parent. This is called hybrid vigour or heterosis (cross breeding)
2. Offspring grows more rapidly and is more economical to rear (cross breeding).
3. It results in the production of pure breeds or pure lines (in-breeding).
4. It helps to concentrate and preserve specific qualities in an animal (in-breeding).
5. Offsprings produced can withstand variations within the environment (cross-breeding)

Disadvantages of Breeding 

1. It may result in in-breeding depression, I.e. a reduction in vigour performance (in-breeding).
2. It can also result in drop in production such as milk, egg, slow growth rate, loss of fertility (in-breeding).
3. It may also result in poor resistance to diseases (in-breeding).

ARTIFICIAL INSEMINATION

CONTENT

This is the introduction of semen into the reproductive tract of the female by a method other than natural mating. The semen containing the spermatozoa are carefully handled,diluted and stored in freezer at a temperature of -1960C in liquid nitrogen until it is required for use.

For artificial insemination to succeed, the following must be ensured

1. Viable spermatozoan must be used.
2. Heat period must been observed.
3. Special handling of spermatozoan because of short life span.
4. Tactical introduction technique.

Method of collection of semen

1. Artificial Vagina
2. Massage method
3. Electro-ejaculation.
4. Recovery of semen from the Vagina after service.

Advantages of artificial Insemination

1. It is easier and less expensive than natural mating since the farmer is saved the expense of maintaining a herd of animals.
2. Easier and cheaper to import semen than whole animal.
3. Larger extent of using one and best male animal’s semen.
4. Handicap of different sizes of female animals is overcome
5. Long use of semen even after death of the male animal.
6. Venereal and infectious diseases associated with mating are easily avoided.
7. Short period of testing with particular semen for research purposes can be achieved.

Disadvantages of Artificial Insemination

1. Expertise experience is needful.
2. Expertise is difficult to come by in term of cost and search.
3. Heat period is unpredictable and limiting.
4. Pregnancy rate may be low if handling procedure is adequate (poor timing of oestrus cycle..
5. Inbreeding may occur if only few males are used. That is low level of heterosis.

Presentation : 

The topic is presented step by step

Step 1: The class teacher revises the old topic

Step 2: The class teacher introduces the new topic

Step 3: The class teacher allows the pupils to give their own contributions and gives room for pupils” participation

Class Teacher and Pupils Activities. Interaction or Participation 

This involves class teacher and pupils’ interaction, conversation, imitation or modeling through discussion, play method or just by recitation or asking and answering questions that are related to the topic that has just been taught.

EVALUATION

1. What is animal improvement?
2. State five aims of animal improvement
3. Define introduction as a method of animal improvement.
4. State three advantages and three disadvantages of introduction.
5. Define selection as a method of animal improvement.
6. State three advantages and three disadvantages of selection.
7. Briefly explain the types of selection.
8. Define selection as a method of animal improvement.
9. State three advantages and three disadvantages of selection.
10. Briefly explain the types of selection.

Conclusion : 

The class teacher concludes the lesson by giving the pupils some notes on the topic that has just been taught. He goes round to mark and he does the necessary corrections.