Breeds-of-Chickens

Development of Modern Breeds and Varieties

  • Wild Jungle Fowl vs Modern Hen

    • Wild jungle fowl: ~0.9 kg weight, few eggs per cycle.

    • Modern hen: 1.5 to 2.0 kg weight, lays ~320 eggs.

Drivers of Change in Breeds

  • Genetic Mutation

    • Changes in genetic makeup from various factors.

    • Transmission across generations; can be modified by environmental interactions.

Selection

Natural Selection

  • Influenced by climatic and nutritional differences.

    Artificial Selection

  • Human intervention aimed at specific goals:

    • Meat

    • Eggs

    • Game fowls

    • Fancy feathers

  • Cross Breeding

    • Often unplanned; involves release of pet breeds.

Standard Classification of Chicken

  1. Class: Groups based on common development areas.

    • American Class: Developed in the Americas (e.g., Plymouth Rock, Wyandottes).

    • Asiatic Class: Originated in Asia (e.g., Brahmas, Cochin).

    • Mediterranean Class: Primarily egg-type breeds (e.g., Leghorn).

    • English Class: Developed in England and colonies (e.g., Dorkings, Cornish).

    • Other classes: Polish, Hamburg, and French classes, including 189 varieties recognized.

  2. Breed: Distinct body structure from other chickens.

  3. Variety: Specific color and comb shape within a breed.

    • Example: Breed - Leghorn, Variety - White, Single comb.

  4. Strain: Continuous selection within a variety for traits over 5-8 years.

Classification by Utility

  • Egg Type: Smaller size; large white-shelled eggs; examples include Leghorn, Minorcas.

  • Meat Type: Larger, slower, and gentler; examples include Brahmas, Cochin, Cornish.

  • Dual Purpose Type: Medium-sized good layers; examples include Rhode Island Red, Plymouth Rock.

  • Fancy/Ornamental Type: Valued for beauty; examples are Frizzle, Bantams.

  • Game Fowl: Bred for resilience and fighting; examples include Ruble, Claret.

Commercial Chickens Classification

  • Egg Type strains: Hyline, Lohmann, Hisex.

  • Meat Type strains: Arbor Acre, Cobbs, Hubbard.

Genetic Basis Traits in Department of Poultry Breeding

  1. Fertility

  2. Hatchability

  3. Livability

  4. Growth rate

  5. Feed efficiency

  6. Egg production characteristics:

    • Sexual maturity age

    • Rate of lay

    • Persistency

  7. Egg size and quality.

  • Heterosis: Crossbred offspring outperform parental averages.

Methods of Mating in Chickens

  1. Pen Mating: One male among several females; labor-efficient.

  2. Stud Mating: Individual males for short mating periods.

  3. Flock Mating: Multiple roosters with females; recommended ratios are followed.

  4. Artificial Insemination: Manual collection and application of rooster's semen.

    • Advantages include control over mating, reduced male-female ratio issues, and prevention of fighting.

Methods of Flock Improvement

  1. Selection Methods:

    Individual Selection: Based on individual performance.

    Family Selection: Whole family selected based on average performance.

    Within Family Selection: Individual performance against family mean.

  2. Breeding Techniques:

    Inbreeding: Mating closely related individuals for purity.

    Crossbreeding: Different breeds for hybrid vigor.

    Strain-Crossing: Combining different strains for trait compatibility.

    Outbreeding: Introducing unrelated individuals to enhance performance. e. Reciprocal Recurrent Selection: Breeding designed for high heterosis.