WEEK FIVE
ANIMAL IMPROVEMENT
CONTENT
- Meaning of animal improvement
- Aims of Animal improvement
- Process/method of animal improvement
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
- To produce animals that can give high yield or products in form of meat, egg, milk etc.
- To produce animals that can provide high quality of products such as yolk size, shell hardness etc.
- To produce animals with high feed conversion efficiency.
- To produce animals with high growth rate.
- To produce animals with early maturity.
- To produce animals which can adapt to climatic/environmental conditions.
- To produce animals that are resistant to parasites and diseases.
EVALUATION
- What is animal improvement?
- State five aims of animal improvement.
PROCESS/METHODS OF ANIMAL IMPROVEMENT
There are three methods or processes of animal improvement. These are;
- Introduction
- Selection
- 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
- Breeds which are not originally present in the home country are introduced
- It enhances greater productivity
- It leads to the absence of pests and diseases
- Breeds may perform better in terms of quality and quantity, if it is able to adapt to local environment.
Disadvantages of introduction
- It may introduce new disease(s) to the new area.
- It may introduce new pet(s) to the area.
- It may have the problem of adaptation to the new area.
- It may not perform maximally
GENERAL EVALUATION
- Define introduction as a method of animal improvement.
- State three advantages and three disadvantages of introduction.
READING ASSIGNMENT
Essential agricultural science by O. A. Iwena Pages 378 – 381.
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
- 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.
- 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:
- Mass selection
- Progeny selection
- Family selection
- Pedigree selection
Advantages of selection
- It ensures that only the best naturally available animal is selected
- Animals with desirable characteristics are selected.
- Animals from the best breeds are bred for distribution.
- Animals with undesirable characteristics are dejected and rejected.
- Selection reduces the spread of diseases.
- It also reduces the spread of parasites associated with breeding stocks.
Disadvantages of selection
- Selection is tedious and time consuming.
- It is very costly in terms of time and money.
- It requires expertise which may not be readily available.
- It brings about elimination or exclusion of some desirable trait of some parents stocks.
- No new desirable characteristics are introduced.
EVALUATION
- Define selection as a method of animal improvement.
- State three advantages and three disadvantages of selection.
- Briefly explain the types of selection.
BREEDING: Breeding involves the development of animals by transferring inherited qualities from parents to offspring. This achieved through mating.
Types of Breeding
- 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.
- 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.
- 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.
- 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
- 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)
- Offspring grows more rapidly and is more economical to rear (cross breeding).
- It results in the production of pure breeds or pure lines (in-breeding).
- It helps to concentrate and preserve specific qualities in an animal (in-breeding).
- Offsprings produced can withstand variations within the environment (cross-breeding)
Disadvantages of Breeding
- It may result in in-breeding depression, I.e. a reduction in vigour performance (in-breeding).
- It can also result in drop in production such as milk, egg, slow growth rate, loss of fertility (in-breeding).
- It may also result in poor resistance to diseases (in-breeding).
EVALUATION
- Define selection as a method of animal improvement.
- State three advantages and three disadvantages of selection.
- Briefly explain the types of selection.
GENERAL EVALUATION
- What is animal improvement?
- State five aims of animal improvement.
- Define selection as a method of animal improvement.
- State three advantages and three disadvantages of selection.
- Briefly explain the types of selection.
- State four factors to consider while carrying out artificial insemination.
READING ASSIGNMENT
Essential Agricultural Science by O.A. Iwena, pages 378-381
WEEKEND ASSIGNMENT
- All the following are aims of animal improvement except A. Fast growth rate B. Egg size C. Susceptibility to disease D. High feed conversion
- …is the process of picking or selecting from a mixed population, those animals with breeding value as parents. A. Introduction B. Selection C. Breeding D. Picking
- The mating of unrelated individual animals within the same breed is called A. Out breeding B. In-breeding C. Line breeding D. Cross breeding
- Sterility could occur during the practices of the following except A. Artificial insemination B. Castration C. Bad hygiene D. Balanced ration intake
- ____ is the ability of individual animals to survive unfavourable environmental weather conditions and reproduce. A. Introduction B. Artificial selection C. Natural selection D. Selective selection.
THEORY
- (a) What is animal improvement?
(b) State five aims of animal improvement. (WASSCE 2013 question 8 a and b).
- Write short notes on the four types of artificial selection.
- Write short note on the following system of breeding
- In-breeding
- Line breeding
- Cross breeding (WASSCE 2000 question 8a).
- State four objectives of animal improvement programmes in West Africa. (WASSCE 2012 question 8c).