This presentation has been supported by the Erasmus
Plus K2 Cooperation Partnerships.
Innovation of the structure and content of study programs in the field of animal
genetic and food resources management
with the use of digitalization innovation.
The European Commission
support for the production of this presentation does not constitute
an endorsement of the contents, which reflects the views only of the authors.
And the Commission cannot be held responsible for any use
which may be made of the information contained therein.
Genetic gain also known as genetic progress
is a basic concept in animal and plant breeding, as well as in agriculture and animal production.
The amount of genetic progress
depends on several factors that I would like to talk about
Today the challenge for livestock production is to meet the growing demand for animal products
while reducing environmental impact.
This means that the performance and resistance of the animals
must be increased as well as the quality of the animal products.
Performance improvement should focus on lifetime productivity,
which can be improved not only by increasing production, but also by improving characteristics
such as health, reproduction and longevity.
The objectives of animal breeding is to genetically improve animals
in a specific direction. Milk yield and composition,
Meat production, egg production and improvement of reproductive
characteristics, fertility and prolificacy
The aim of breeding is to obtain animals with a better genotype in the next generation.
For this reason, the process of genetic improvement is stretched over time.
This is a detailed diagram of the genetic improvement of the population.
each species of animals used by
humans has its breeding program, which is the basis
for improving important functional characteristics such as those mentioned a moment ago.
The elements of the breeding program are the breeding goal,
the control of current performance and the collection of this information.
The selection system for suitable slash best individuals
from the population and the mating system.
Finally, an assessment of the transfer of progress
in the production population
The optimal breeding
program is adapted to the specificity of a given species and the characteristic
included in the
breeding goal.
The breeding program is aimed at genetic improvement
through the selection of individuals for the parents of the next generation.
The breeding goal express es the combinations of traits
that the breeder wants to improve in the selection process.
The amount of progress achieved in the breeding goal and the traits included in it
depends on the accuracy of selection, its intensity and the spacing of generations.
Breeding program for dairy cattle – objectives
The objectives of improvement in the breeding program
for dairy cattle are for the production characteristics with particular
emphasis on the composition and quality of milk, which have a large impact on its price.
That is the content of fat, protein, dry matter and milk
functional characteristics that have a significant impact on reducing production
costs, such as features of the external structure of the body,
fertility, health of the udder, longevity of animals,
features of milking capacity, ease of childbirth.
of the pig breeding program are mainly related
to the improvement of
reproductive characteristics
such as number of piglets born, number of piglets weaned,
number of teats per female and age of her first calving.
In addition to reproductive performance, an important element
in pig breeding are meat performance characteristics, fattening and slaughter
such as daily weight gain meat content
in the carcass area of the eye of the loin, intramuscular fat content,
water absorption, active acidity, color and texture of meat
The basis
for obtaining
offspring with better characteristics than the parents is to know the value
milk, yield, carcass value, or laying value of the parents.
Then preparing such a ranking, ranking in terms of the features selected for improvement.
Selection as a process that changes the frequency of genes and genotypes
in the selected population allows for the achievement of the objectives of the breeding program,
which most often focuses on improving the breeding value of a selected group of traits
in order
to maximize profit.
In assessing
the effects
of the selection of quantitative measurable traits.
It is helpful to compare the average phenotypic and breeding values of the improved traits.
If selection is affected, if the offspring is clearly genetically superior to the parent.
Distribution of breeding value of offspring
from mating parents with known values
Knowledge of the laws of inheritance makes it possible to predict the value
of offspring for mating parents with known breeding values.
Unfortunately, the same laws regarding the randomness of gene transmission
mean that the expected effect may not be achieved at all.
In practice, the breeder can obtain
both higher and lower value animals.
The measure of successful selection is the appropriate
response of the population to the breeding methods used, which means that the offspring
of the selected parents will be much better than the parents generation.
Genetic gain is the difference between the average breeding
values of individuals from successive generations.
Genetic gain is the product of heritability
and selection difference.
Genetic gain
Genetic gain, therefore,
is the difference between the genetic value
of a given trait in the offspring
and the value of that trait in the parent herd,
obtained as
a result of selection
that resulted in a favorable change in gene frequency in the progeny
compared to the parents.
Genetic gain
is the measure of the magnitude of the population's response to selection.
It is defined as the difference between the average breeding values of the progeny
and the parent generation.
I mentioned
at the beginning that the value of genetic progress depends on several factors.
These are accuracy of the assessment at the genetic value of individuals
subjected to selection, selection, intensity, genetic variability of the selected trait.
Heritability of the selected trait
I'll start with the first factor
the accuracy
of the assessment
at the genetic value of individuals subjected to selection,
which is reflected in the correlation between the phenotypic and genetic value of individuals
and the assessment of the breeding value is preceded
by the determination of the value of phenotypic traits.
That is the assessment of performance.
These are continuous processes.
A number of methods are used to assess the breeding value.
Methods of evaluating breeding value are subject to modification.
Due to emerging modern techniques e.g.
related to the development of molecular genetics, genomic evaluation,
as well as resulting from breeding reasons increase in the level of performance characteristics of animals.
Inclusion of new breeding goals, modifications of breeding programs, etc..
An important feature of modern breeding value assessment methods is that they allow to separate
the influence of environmental factors such as year of birth, season season, micro
climatic conditions, nutrition, region of the country and others
on the level of production characteristics.
Thus, the obtained ratings characterize
the potential production possibilities encoded in the animals genes,
the appropriate size of the so-called active population.
That is, the proportion of animals subject to control and evaluation
of breeding value in relation to the entire population of a given species breed, line.
Using in the assessment not only the phenotype of the evaluated animal,
but also information on the performance of its ancestors.
Collateral relatives and offspring contributes
to increasing the accuracy of animal assessment.
That is,
the selection of individuals
for the parents
of the next generation
is the basic tool of the breeder
thanks to which, he can pursue the set breeding goal.
In the case of selection, we care about choosing the best animals, that is,
those with the highest breeding values.
In most cases,
the selection criterion
is assumed to have
a normal distribution.
The term selection of the best animals is imprecise.
The figure shows the distribution of most traits of great
economic importance in animal husbandry.
Depending on the breeders determination
fewer individuals can be selected for the selection herd,
and then the selection intensity will be high.
You can select more individuals.
For example, about 30%.
And then the selection intensity will be lower than after the interests of most selected venture you show.
The intensity of selection is greater in males than in females.
Among the males, only about 0.5
to 2% of the best individuals are mated with females.
Some tell me
the value of genetic gain
also depends on genetic variation of the selected trait.
Genetic variability consists in the diversity
of the genetic endowment of individuals in a population and arises
under certain environmental conditions as a result of the action of many factors.
If you are not to
the value of genetic gain
also depends on the heritability of the selected trait.
Heritability expresses the extent to which
a trait is passed from parents to offspring.
When heritability is high, more than 0.4.
We observe greater phenotypic similarity
between closely
related individuals
The process
of genetic improvement of animals must go hand in hand
with providing them with optimal housing conditions and a high level of welfare.
Because the effective implementation of the breeding goal depends
on the interaction of two basic factors genotype and environmental conditions
for example, a sow with the best possible genotype will not produce large numbers of piglets.
If veterinary care is neglected or if he ration is deficient in nutrients,
Finally,
I wanted
to give
two examples
of visible genetic gain: in dairy cattle
it is an increase in milk yield in subsequent years
of the breeding program.
In pigs it is an increase in the meat content in the carcass
of paternal and maternal breeds and crosses of the progeny generation
In conclusion,
genetic gain is an improvement
of a selected trait or multiple traits in a population over generations,
even a process that consists in identifying individuals with outstanding
genetic characteristics and using them as parents for the next generation.
By selecting and breeding these individuals,
their valuable genetic material is passed on to the offspring,
which leads to an increase in the frequency of desired traits in the population.
Genetic gain depends on several factors, including the heritability of the traits of interest,
the intensity of selection, the genetic variation in the population,
and the time needed to complete
one breeding cycle
Thank you for your attention.