Inbreeding and line breeding are types of animal breeding where closely related individuals are mated. Inbreeding increases homozygosity and can help establish desirable traits, but excessive inbreeding leads to inbreeding depression over multiple generations. Inbreeding depression reduces fertility and litter size due to increased genetic disorders and lower immune function in offspring of related individuals. While inbreeding brings genetic purity, it also has disadvantages like reduced productivity if taken to an extreme.

1. M.SC. ZOOLOGY 1st SEMESTER
SUBJECT : ANIMAL BREEDING
NAME: ABHIJEET PATTJOSHI
REGD.NO : 200705180006
SESSION: 2020-2022
TOPIC NAME: INBREEDING AND LINE BREEDING
GUIDED BY: MR. PRADIP KUMAR PRUSTY
SCHOOL OF APPLIED SCIENCE, BHUBANESWAR

2. CONTENT
• Meaning of Animal Breeding
• Types of breeding in animals
• Meaning of Inbreeding
• Impact of Inbreeding
• Types of Inbreeding
• Advantages of Inbreeding
• Disadvantages of Inbreeding
• Inbreeding Depression
• Conclusion

3. ANIMAL BREEDING
• Breeding is sexual reproduction that produces offspring,
usually animals or plants. It can only occur between a male
and a female animal or plant.
• Animal breeding is the process of selective mating of
animals with desirable genetic traits, to maintain or enhance
these traits in future generations.

4. TYPES OF BREEDING
Breeding in animals takes place in 2 different types, which are:
1. Inbreeding
2. Outbreeding
1. Inbreeding:
Inbreeding is the mating of closely related individuals within
the same breed for 4-6 generations.
2. Outbreeding:
Outbreeding is the mating of animals of the same breed
but which have no closer relationship than at least 4-6
generation.

5. INBREEDING
• Inbreeding is the production of offspring from the mating
or breeding of individuals or organisms that are closely
related genetically.
(Or)
• Inbreeding means mating of individuals that are related to
each other by ancestry.
Example : Sire to daughter, son to dam, brother to sister

6. IMPACT OF INBREEDING
• Inbreeding increases the proportion of homozygosity which
enhance the chances of offspring being affected by
recessive or deleterious traits.
• It creates lot of genetic disorder like haemophilia, sickle cell
anemia and so on.
• Inbreeding is basically used in selective breeding like
livestock- to establish new desirable traits in the stock.
• Inbreeding often leads to reduction of litter size and
fertility.
• Inbreeding is totally opposite to outbreeding.

7. INBREEDING IN A DIAGRAM

8. TYPES OF INBREEDING
There are again two types of inbreeding which are:
1. Close breeding :
• This is most intensive breeding where animals are
very closely related and can be traced back to more
than one common ancestor.
• Examples: Sire to daughter, Son to dam, Brother to
sister.
2. Line breeding :
• Mating animals that are more distantly related
which can be traced back to one common ancestor.
• Examples: Cousins Grandparents to grand offspring,
Half-brother to half-sister. Line breeding increases
genetic purity amongst the animals of progeny
generations.

9. ADVANTAGES OF INBREEDING
• Inbreeding brings the homozygosity
in the population so it helps in producing pure line of
animals.
• It helps in accumulation of superior genes and
elimination of less desirable genes and hence
increases the productivity of inbred population

10. DISADVANTAGES OF INBREEDING
• Reduced fertility both in litter size and sperm viability
• Increased genetic disorders
• Lower birth rate
• Higher infant mortality and child mortality
• Loss of immune system function
• Leads to inbreeding depression

11. INBREEDING DEPRESSION
• Inbreeding depression is the reduced biological fitness in
a given population as a result of inbreeding, or breeding
of related individuals.
• Inbreeding depression is the reduced survival and fertility
of offspring of related individuals.
• It occurs both in plant and animal population, as well as in
humans.

12. INBREEDING DEPRESSION

13. CONCLUSION
• Inbreeding means mating of individuals that are related
to each other by ancestry.
• There are two types of inbreeding which are:
1. Close breeding
2. Line breeding
• Inbreeding increases the homozygosity and helps in
producing pure line.
• However, excessive inbreeding reduces fertility, litter
size and ultimately leads to inbreeding depression.

14. REFERENCES
• https://www.britannica.com/science/animal-breeding
• https://en.wikipedia.org/wiki/Animal_breeding
• https://www.sciencedirect.com/topics/biochemistry-
genetics-and-molecular-biology/inbreeding
• https://evolution.berkeley.edu/evolibrary/article/conserva
tion_03