Question

Mating of the related individual with 4-6 generation is known as

• A. Inbreeding
• B. Line breeding
• C. Close breeding
• D. Out breeding

Hint:

Remember the division of Inbreeding:
- Extremely close relatives (1-2 generations) $\rightarrow$ Close Breeding.
- Moderately related relatives (4-6 generations) $\rightarrow$ Line Breeding.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Animal breeding strategies use controlled mating systems to improve genetic traits in livestock.
Mating systems are broadly classified based on the genetic relationship between the parents:
- Inbreeding: Mating of individuals that are more closely related than the average of the population.
- Outbreeding: Mating of unrelated individuals.
Inbreeding is further subdivided into close breeding and line breeding based on the closeness of the relationship.

Step 2: Detailed Explanation:
Let us define and distinguish between the breeding systems listed:
1. Close Breeding:
This is an intense form of inbreeding where highly closely related individuals are mated.
Examples include mating sire to daughter, dam to son, or full brother to full sister (within 1 to 2 generations).
While it rapidly fixes desirable genes, it also increases the risk of inbreeding depression and genetic defects.
2. Line Breeding:
This is a milder, more selective form of inbreeding designed to maintain a high genetic relationship to an outstanding ancestor.
It involves mating individuals that are more distantly related, typically sharing a common ancestor 4 to 6 generations back (e.g., half-siblings, cousins, grandparents to grand-offspring).
This strategy allows breeders to concentrate the desirable traits of a superior ancestor while minimizing the risks of severe inbreeding depression.
Therefore, this description matches the question.
3. Inbreeding:
While line breeding is a form of inbreeding, "inbreeding" is a broad category.
The specific term for mating individuals related within 4 to 6 generations to maintain a relationship to a specific ancestor is "line breeding."
4. Out Breeding:
This is the mating of completely unrelated individuals (belonging to different families, breeds, or species) to introduce new genetic variation.

Step 3: Final Answer:
Mating related individuals within 4 to 6 generations is known as line breeding.
Therefore, the correct option is (B).