“It is an application of genetic principles to improving
heriditory for economically important traits in domestic
Ex: Improving of milk production in dairy animals
Egg production in chickens
Produce individuals with superior merits
Improvement of the characteristics.
Production of new traits.
Hand mating: In this method male and female are
brought together for a brief period and then separated
once the mating is over.
Ex : Rabbits and Hamsters are mated by this
Pair mating : This is the method in which male and
females are mated together rest of their breeding life.
In this method in case of mice one male mated with
one female , and left together for the rest of their
In the case of rats, pregnant females should be
isolated prior to delivery.
Harem mating : In this method males and females are
run together , but separated prior to parturition
In this method four females are regularly mated with
The female is separated soon after the pregnancy is
established, and replaced by fresh females.
Ex : guinea pigs are mated by this method.
Cross breeding : Criss crossing
“The crossing of two closely related genes is called
In this individuals are mated 4-6 generations.
Develop lines which commercially used.
Inbreed should have at least 50% coefficient of inbreed.
It is used to return desirable genetic characters.
Identify harm full genes.
Increase frequency of homozygocity .
Higher susceptibility to genetic disorders.
Risk of inbreeding depression I . e infertility , delayed
maturity , slow growth , decrease egg production.
hybrid vigor and fertility were lost due to repeated
Line breeding : This is the breeding of animals that share
common ancestors but are not closely related.
Line-breeding over successive generations will result
in more variations of physical appearance
Close breeding : In this mating the breeding is done
between brother-sister , dam-son etc.
The crossing of distantly related animals is called
In this method it is possible to breed a desirable type
of animal with a less desirable type and then to
increase the degree of desirable traits.
New and high yielding genes can be introduced into
the population through out -breeding.
They produce some valuable traits
Can create new breeds
Can produce a hybrid of superior vigor and value.
Introduction of new genes into population.
Out – crossing : It is system of mating where un related
animals with in the same breed.
Cross breeding :
a) Criss cross : Mating of two different breeds
Hampshire Vs Landrace
Progeny 1 Vs Hampshire
Progeny 2 Vs Landrace
It can produce pigs with different levels of inheritance.
b)Triple crossing : mating of three different breeds in
Cross breeds have different proportions for all three
Hampshire Vs landrace
• Progeny 1 Vs large black
Progeny 2 Vs Hampshire
Progeny 3 Vs Landrace
c)Back crossing : Mating of cross bred animals to one of
pure bred parents which were used to produce them.
Aa Vs AA
2AA , 2Aa
It is the system of breeding purebred sire to non
descript breed generation after generation.
Level of exotic breed inheritance increase upgraded
stock up to 99% in the 7th generation.
Selection and breeding are two main tools to produce
“sudden change in the genetic material”
The new traits into populations can also be induced
Most of the mutations are harmful and the process of
induction of this method of improvement of animals is
Eg : poultry that is resistant to white diarrhoea ,
increased egg production in fowls, increased fat
content in milk and better meat yielding in Turkeys etc.