Animal Breeding II SS1 Livestock Farming Lesson Note

In our last lesson, we looked at how we select the best animals and the difference between natural mating and “AI” (Artificial Insemination). Today, we are going to look at the different systems of mating.

Think of this like a family tree. Depending on how closely the parents are related, the “family” will turn out differently. In livestock farming, we use three main systems: Inbreeding, Linebreeding, and Crossbreeding.

Inbreeding (The “Close Family” System)

Inbreeding is when you mate animals that are very closely related. Examples include mating a father to his daughter, or a brother to a sister.

Why would a farmer do this? Usually, it is to make a particular trait “stick.” For example, if a family of pigs has a specific type of white skin that people like, inbreeding keeps that color pure.

Advantages:

• It makes the breed “pure” (Uniformity).
• It helps the farmer identify bad traits in a family so they can be removed.

Disadvantages:

• Inbreeding Depression: This is the biggest problem. The babies often become small, weak, or lose the ability to have their own babies.
• Diseases can spread or become more common in the family.

Linebreeding (The “Cousins” System)

Linebreeding is actually a milder form of inbreeding. Instead of mating brothers and sisters, you mate animals that are distantly related—like cousins or a grandfather to a granddaughter.

Why do we use it? It is safer than inbreeding. It allows the farmer to keep the “good blood” of a famous ancestor (like a legendary bull) in the herd without the high risk of making the animals weak.

Advantages:

• It maintains the good qualities of a specific ancestor.
• It is less risky than close inbreeding.

Disadvantages:

• If not done carefully, it can still lead to the same problems as inbreeding over a long time.

Crossbreeding (The “Mix-Match” System)

This is very common in Nigeria! Crossbreeding is mating two animals from different breeds. For example, mating a local “Muturu” cow (very tough and survives diseases) with a foreign “Holstein” cow (produces massive amounts of milk).

Advantages:

• Hybrid Vigor (Heterosis): This is a fancy way of saying the baby is often better than both parents! It grows faster, is stronger, and produces more.
• It combines the best of two worlds (e.g., the toughness of the local breed and the high production of the foreign breed).

Disadvantages:

• The farmer might lose the “pure” local breed over time.
• It requires more money because crossbred animals often need better food and medicine than local ones.

Summary Table of Advantages & Disadvantages

Conclusion: Which should a farmer choose?

Most small-scale farmers in Nigeria find Crossbreeding to be the most profitable because the animals grow faster and bring in more money. However, big research farms use Inbreeding to make sure they have pure seeds to sell to others.

As a student, the rule is simple: Avoid mating close relatives (Inbreeding) in your backyard farm, or your animals will eventually become small and sickly!

Class Discussion / Homework

1. Explain why a farmer might see his goats getting smaller every year if he keeps only one male for many years. (Hint: Think about Inbreeding).
2. What is “Hybrid Vigor”?

Project: Go to a nearby farm or ask a local cattle herder. Ask them if they have “Crosses” (mixed breeds) and why they like them. Write down their answer in three sentences.