chapter2 Flashcards
a segment of the DNA
[deoxyribonucleic acid)
gene
Store and transmit information from cell to cell (mitosis)
and from parent to offspring (meiosis)
gene
Each nucleotide consists of
phosphate
(P),
a sugar (S) and
a base (B)
how many chromosomes of Chicken
78 chromosomes, 39 pairs
how many chromosomes of Turkey
82 chromosomes, 41 pairs
how many chromosomes of Duck
80 chromosomes, 40 pairs
Responses to selection depend
on the extent to which the traits
are inherited.
SELECTION METHODS
This inheritance level is
expressed by the so-called
heritability (h2
).
Pure lines are primarily
developed by use of
closed
flock selection
SELECTION PROCEDURES
Based on individual Performance
Based on the Performance of their
Sibs (family selection)
Moderately to Highly Heritable Traits
Physical characteristics
Productive traits
Lowly Heritable Traits
Biological fitness
Reproduction
a selection procedure to find the lines with the best combining
ability
RECIPROCAL RECURRENT SELECTION PROGRAM
The end products are generally originating from 4 different lines.
This is called a
4-way-crossing
Characteristics most often considered in selecting pure-line breeders are:
Growth
Reproduction
can be classified depending on whether it is
aimed to increase homozygosity or heterozygosity.
SYSTEM OF BREEDING
a breeding system means each possible mating in a population
has the same probability or occurrence. Normally used in breeding
experiments to minimize genetic changes in a control population
wherein selected populations are controlled.
Random Mating
mating between individuals which are more closely
related to each other than the average relationship between all
individuals in a population. It can be consistently carried out for
several generations.
Inbreeding
under Inbreeding system
Close inbreeding
Strain Breeding
Line breeding
- opposite of inbreeding. Mating of animals that are less
closely related. Mating between strains or inbred lines are the forms of
outbreeding.
Outbreeding
- Two different populations (inbred lines, strains or breeds)
are crossed to produce a first filial (F1) generation.
Single or 2-way cross
In this method, F1 crossbred females (AB) are mated to males
of a third line (C), to obtain a F2 progeny (ABC)
Three-way cross
Mating between sibs and parents and progeny.
Full sib mating and backcrossing of the progeny to the younger of
the parents are often practiced.
Close inbreeding -
- Developing a small group of animals within a
breed and variety with a special character in view. This is a mild form
of inbreeding.
Strain Breeding
inbreeding with an ancestral line and is the most
intensive form of back-crossing. Line breeding is backcrossing to the
same parent for several generations in succession.
Line breeding
METHODS OF MATING
Pen mating
Flock mating
Stud mating
Artificial Insemination (AI)
– the usual method of pedigree breeding of chicken to
segregate a single male with a group of females for the period of
breeding season.
Pen mating
– several males to females ; system by which two or
more roosters go with the hens in the pen.
Flock mating
– males are penned and females are brought to them
after every 3 eggs lay; usual procedure to have a male confined at all
times to individual pens and female will be introduced,
Stud mating
is defined as the pairing of a male and a female for the purpose
of reproduction or production of young ones.
Mating
is the technique by which seminal fluid
(semen) of male is introduced or deposited into the female
reproductive tract by a pipette.
Artificial Insemination (AI)
Artificial Insemination (AI) Advantages:
- Allows an unlimited number of single male mating without requiring
extensive breeding equipment - Accurate Pedigree possible
- If, due to some reason, a male of superior qualities cannot mate, it
can still contribute to the next generation - The incidence of sexually transmitted diseases is reduced or avoided
Artificial Insemination (AI) Disadvantages:
It requires more labor
* Chances of cross-contamination of birds through the inseminating
equipment
* Involves handling of birds which may cause stress.
It is a red
wild chicken that is widely spread in the East-Java, Burma, Thailand and
Sumatra
Red jungle fowl (labuyo), Gallus bankiva
it is pale gray wild chicken that is
widely spread in South and West India.
Gray jungle fowl ,G. sonnerati
It is a wild chicken found in Sri lanka.
- Ceylon jungle fowl, G. lafayeti
It is a Javanese wild chicken that
is widely spread on the Island of Java and lesser Sunda Island
Java (green) jungle fowl, G. varius
widely believed to be the most probable ancestor of
the modern chicken.
Red jungle fowl
- Some changes in the genetic make-up of certain
individuals due to factors that are within as well as
factors that surround the subject.
GENETIC MUTATION
The change have been transmitted from generation
with the possibility of being modified from time to time
as more factors and individuals interact with each
other.
GENETIC MUTATION
types of SELECTION
Natural selection
Artificial selection
it is the type of selection that (survival of the fittest),Climatic differences
,Difference in nutrition.
Natural selection
it is the type of selection that the interference of man in achieving
certain goals and personal ideals in improving the
chicken for meat, for eggs, for fighting cocks, for fancy
feathers
Artificial selection
CLASSIFICATION OF BREEDS AND VARIETIES
Class
Breed
Variety
Strain
Class – a group of chicken that were developed in common area
a group of chickens (fowls) possessing certain
conformation or shape of body that distinguishes them from
other chickens.
Breed
– a group of chickens within a breed that have the same
plumage color and type of comb.
Variety
a group of chickens within a variety of a breed which
has undergone constant specific selection for certain traits by a
specified breeder for periods of about 5 to 8 years.
Strain
The existing breeds of poultry are classified into 2
ways:
(1) Economic/Utility Classification and
(2) Standard Classification
Egg type chicken
Leghorn
Minorca
Ancona
Mikawa
Meat type
Brahma
Cochin,
Langshan
Cornish
white rock
General/ Dual-
purpose type
Rhode Island Red,
New Hampshire,
Plymouth Rock,
Lancaster, Nagoya,
Cantonese
Fancy Class
Silkies
Bantams &
Frizzle
Fighting Class
Hatch, Sweater, Claret,
Lemon, Whitehackle,
Roundhead, Orientals,
Regular grey, Dom,
Butcher, Kelso, Brown
red, Muff
American class
Plymouth Rock, Wyandotte,
Rhode Island Red, New
Hampshire, Lancaster
Asiatic class
Brahma, Cochin, Langshan,Cantonses, Nagoya
English class
Orpington, Cornish, Sussex &
Australorp
Mediterranean class
Leghorn, Minorca & Ancona
SELECTION OF BREEDERS
Health and vigor
Body conformation
Size
Color
Head
Wings and tail
Shanks and toes
Combs
Egg performance
SELECTION OF GOOD BROILERS
Appear healthy and lively
- Feathering shiny and normal (may depend on the breed)
- Large size for the age
- Eyes clear and shiny
- Clean and dry beak and nostrils
- Clean feathers around the vent
- Straight legs and toes
SELECTION OF GOOD LAYERS
Should appear healthy and lively.
- Feathering normal for the breed.
- A red comb (more colored when in lay).
- Eyes clear and shiny.
- Clean and dry beak and nostrils.
SELECTION OF GOOD COCK
- Alert and protective nature.
- Shiny and normal feathering for the breed.
- Clear and shiny eyes.
- Clean and dry beak and nostrils.
- Clean feathers around the vent.
- Straight legs and toes with no signs of scaly legs.
- Large size relative to the hens.
SIMPLE RULES TO CHOOSE THE RIGHT BREED AND IMPROVE
SELECTION
- Practice judging the external features of cocks, hens, growers,
and chicks, to know which features indicate a good healthy and
productive animal. - Always choose birds with a lively behavior.
- Always check whether the hens are in lay.
- A potentially good layer has a long straight back and a broad
bottom. - Always check the belly and navel spot of newly hatched chicks.
PROSPECT OF NATIVE CHICKEN
*Increasing demand for chicken meat with strong flavor.
- Conforms with criteria for organically produced products.
- Animal Welfare Act and humane management system.
- Meat available in live, fresh and fresh-chilled, and cut-up
parts forms. - Preference for intense yellow-colored egg yolk.
*Not import dependent
POTENTIAL OF NATIVE CHICKEN
- Can survive without expensive feeds and inputs.
- Well-adapted to climatic extremes.
- Can live and reproduce even under harsh conditions,
- Resistant to many known diseases that plague modern breeds
- Good ranging ability.
- Can convert farm by-products and other traditional feeds into
meat, eggs and fertilizer,
how many percent of Laying period livability in native chicken
More than 80%
how many clutches per year Egg production in native chicken
10-15 per clutch; 60-100 per year
