D4: The layer type fowl (breeding goal, use, breeds, traits, breeding methods)

Question 1

what is the breeding goal?

Answer 1

• Raise strong laying hens that produce eggs of highest quality, require less feed, white/brown eggs
• increased Egg number, feed efficiency and egg quality

Question 2

use of layer type fowl:

Answer 2

• Meat
• Egg production
• Pet

Question 3

mention some layer type fowl breeds and their characteristics

Answer 3

• Hybrids: Golden Comet
  -> Laying huge amounts of eggs while consuming small amounts of food (280 eggs/year).
  -> White Leghorn x Rhode Island Red.
• Rhode Island: Dual purpose (eggs + meat) tough (250 eggs/year).
• Leghorn: Italian descent. (250 eggs/year) fully white body, large comb.
• Sussex: Dual purpose, 250 eggs/year.
• Plymouth rock: 200 eggs/year, Grey with white stripes.
• Ancona,
• Barnevelder
• Hamburg
• Marans
• Buff orpington

Question 4

difference btw white and brown egg laying hens

Answer 4

• Layer Breeds: white eggs and brown egg laying hens.
• With egg laying hens: smaller in size, eat less.
• Brown egg laying hens: relatively larger, eat more, lay bigger eggs.

Question 5

Egg production traits of layers

Answer 5

• Puberty, laying maturity, Early sexual maturity.
• Laying performance, egg production:
  o Good rate of laying, h2 = 0.15-0.25
  o Relative egg production
  o Absolute egg production (>300 = excellent layer)
• 1st year production:
  o Forms basis of determining egg-laying ability
  o First year eggs are smaller than that of the second year.
• Intensity of egg laying refers to the clutch size, a larger intensity means a longer egg laying period without intervals
• Egg quality:
  o Weight and size: XL = >73 g, L = 63-67 g, M = 53-63 g, S = <53 g
  o Interior egg quality (egg white, albumen size, size of egg yolk, cholesterol content)
  o Shell quality
• Broodiness
  o Non-broodiness is desirable, intensive selection against broodiness, most of hybrids are not broody.
• Mortality rates: 0.5-1.0% monthly

Question 6

Breeding systems and methods:
Methods of mating

Answer 6

o Flock or mass mating: with one cock and a group of hens
o Stud mating or hand mating – individually and artificial insemination (turkey only?)

Question 7

Breeding systems and methods:
selection methods

Answer 7

o Mass selection based on individual performance or appearance
o Family selection: sisters and brothers of a hen
o Pedigree selectio

Reciprocal recurrent selection (RRS), and recurrent selection (RS): Testing for the best combination ability (optimal combining,
heterosis) based on performance testing of progeny;

Reciprocal means: both paternal and maternal lines are tested in both lines (in reciprocal crossings: A-hen×B-cock and B-hen×Acock) and at the same time both lines are selected;

Question 8

Breeding systems and methods:
breeding of laying hybrids

Answer 8

purebred breeding
line crossing

*Crossing of inbred lines: rare within the same breed, only in laying hen and chicken breeding (2-way-crossing, 3-waycrossing).

*Outcrossing of lines (frequently 2-line-crossing): , only the best combination is used and bred with highest heterosis effect.