Lesson Notes By Weeks and Term - Senior Secondary 3

TERM – 1^ST TERM

WEEK THREE

Class: Senior Secondary School 3

Age: 17 years

Duration: 40 minutes of 5 periods each

Date:

Subject: ANIMAL HUSBANDRY

Topic: METHODS OF FARM ANIMAL IMPROVEMENT

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

I.) Define breeding

II.) Identify the advantages and disadvantages of breeding

III.) Define hybridization

IV.) Identify the advantages and disadvantages of breeding

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures,

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

NOTE

METHODS OF FARM ANIMAL IMPROVEMENT

3. BREEDING

Breeding is a method of animal improvement, involves selectively mating animals with desirable traits to produce offspring with those desired characteristics. This process aims to enhance specific traits within a population over successive generations through controlled reproduction.

Advantages of breeding

1. Breeding allows for the improvement of desired traits such as productivity, disease resistance, or temperament by selecting parent animals with superior characteristics.
2. Breeders have the ability to directly influence the genetic composition of the population by selecting specific individuals for mating, leading to targeted genetic improvements.
3. Breeding programs can be tailored to meet specific production goals or environmental conditions, resulting in animals that are better suited to their intended use or local climate.
4. Through careful selection and breeding, populations can be developed that are more resilient to environmental challenges, reducing reliance on external inputs and promoting sustainable agricultural practices.

Disadvantages of breeding

1. Continuous breeding from a limited pool of individuals can lead to inbreeding, which increases the risk of genetic disorders and reduces overall genetic diversity within the population.
2. Small breeding populations are susceptible to genetic drift, where random fluctuations in allele frequencies occur over time, potentially leading to loss of genetic variability and decreased adaptability.
3. Breeding programs typically require multiple generations to achieve significant improvements in desired traits, leading to long breeding cycles and delayed results.
4. Despite careful selection, the expression of traits in offspring can be influenced by complex interactions between genes and the environment, leading to variability in performance outcomes and potentially unpredictable results.

4. HYBRIDIZATION

Hybridization, as a method of animal improvement, involves crossing individuals from two different breeds or populations to produce offspring with a combination of desirable traits from both parental lines. This process aims to capitalize on the phenomenon of hybrid vigor or heterosis, where the offspring exhibit superior performance compared to their parents.

Advantages of hybridization

1. Crossbreeding can result in offspring with enhanced vigor, productivity, and disease resistance compared to purebred individuals, due to the mixing of diverse genetic backgrounds.
2. Hybridization allows breeders to combine desirable traits from different breeds or populations, leading to animals that possess a broader range of beneficial characteristics.
3. Hybrids often exhibit improved performance traits such as growth rate, fertility, and overall health, making them more economically valuable in agricultural production systems.
4. Hybrids may exhibit increased adaptability to diverse environmental conditions, making them suitable for a wider range of production environments.

Disadvantages of hybridization

1. Hybrid populations may exhibit greater phenotypic variability compared to purebred populations, making it challenging to maintain uniformity in traits such as size, color, or conformation.
2. While hybrid vigor is generally advantageous, the extent of heterosis can vary widely depending on the specific traits being evaluated and the genetic backgrounds of the parent lines, leading to inconsistent performance outcomes.
3. Some hybrids may exhibit reduced fertility or reproductive performance, particularly in later generations, which can pose challenges for breeding and maintaining stable populations.
4. Continuous reliance on hybridization for genetic improvement may lead to the loss of valuable indigenous breeds or populations, as well as increased dependency on external breeding programs and genetic resources.

EVALUATION: 1 Define breeding

2. Identify 3 advantages and disadvantages of breeding
3. Define hybridization
4. Identify 3 advantages and disadvantages of breeding

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively