Livestock Breeding Techniques JS 3 Note

JSS 3 LIVESTOCK FARMING LESSON NOTE

FIRST TERM | WEEK 3: LIVESTOCK BREEDING TECHNIQUES

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1. Natural Insemination (Natural Mating)

Natural Insemination is the physical process whereby a fertile male animal (sire) naturally mounts a female animal (dam) during her heat period and deposits semen directly into her reproductive tract.

Common Natural Mating Systems:

• Pasture / Flock Mating: Males and females graze together continuously on pasture. Mating occurs freely whenever a female comes into heat.
  • Advantage: Low labor requirement.
  • Disadvantage: Sire identity and exact mating dates are difficult to track.
• Pen Mating: A selected male is housed in a pen with a specific group of females for a defined breeding period.
• Hand Mating: The female in heat is brought individually to a selected superior male's pen for a controlled mating session under farmer supervision, after which they are separated.
  • Advantage: Accurate record of mating date and fatherhood.

2. Artificial Insemination (AI)

Artificial Insemination (AI) is a scientific breeding technique in which viable semen is collected manually from a genetically proven superior male, evaluated, diluted, preserved, and later deposited into the female's reproductive tract using specialized instruments during her natural or induced heat period.

Main Steps in Artificial Insemination:
1. Semen Collection: Collected from superior males using an Artificial Vagina (AV) or electro-ejaculator.
2. Semen Evaluation & Dilution: Checked under a microscope for sperm motility and density, then diluted with extenders.
3. Semen Preservation: Frozen in plastic straws at −196°C in liquid nitrogen tanks for long-term storage.
4. Insemination: Thawed semen straw is loaded into an AI gun and deposited into the female cervix/uterus during standing heat.

3. Equipment Used in Artificial Insemination

AI Equipment	Function / Purpose
Artificial Vagina (AV)	Collects semen from the male by mimicking the temperature, pressure, and lubrication of a female tract.
Liquid Nitrogen Tank	Stores frozen semen straws at extremely low temperatures (−196°C) for years without losing viability.
Semen Straws	Thin plastic tubes used to hold individual doses of processed/diluted semen.
AI Insemination Gun / Syringe	Stainless steel tube used to hold the thawed straw and push semen through the female cervix into the uterus.
Plastic Sheath & Gloves	Provides sterile protection over the AI gun and protects the technician's arm during rectovaginal insertion.

4. Advantages and Limitations of Artificial Insemination

Advantages of AI:

1. Genetic Improvement: Semen from top-quality bulls, rams, or bucks can be used to upgrade local herds rapidly.
2. Cost Reduction: Eliminates the high expense of buying, housing, feeding, and managing aggressive breeding males on small farms.
3. Disease Control: Prevents the transmission of venereal/sexually transmitted diseases (e.g., Brucellosis, Trichomoniasis).
4. Overcomes Physical Size Mismatch: Allows heavy males to breed lighter females safely without physical injury.
5. Long-Distance Breeding: Semen can be transported across international borders easily without shipping live animals.
6. Extended Use of Sire: Semen from an outstanding sire can still be used long after his death.

Limitations / Disadvantages of AI:

• Requires trained, highly skilled technical personnel to operate equipment and deposit semen accurately.
• Requires careful heat detection by the farmer; missing heat signs leads to failure.
• High initial capital cost for specialized refrigeration equipment and liquid nitrogen supply.
• Risk of spreading genetic defects widely if an unproven male's semen is used indiscriminately.

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CLASS EVALUATION & REVISION QUESTIONS

1. What is artificial insemination?
2. State three differences between natural mating and artificial insemination.
3. Why is liquid nitrogen used in storing livestock semen? At what temperature is it kept?
4. Explain four benefits a smallholder livestock farmer gains by adopting artificial insemination.
5. List two reasons why artificial insemination might fail on a farm.

HOME ASSIGNMENT:
Draw and label three pieces of Artificial Insemination equipment (Liquid Nitrogen Tank, Semen Straw, and AI Insemination Gun) in your exercise book, stating one function for each.