Genetic

• Breeds of Chickens

  • Broiler: Plymouth Rock, New Hampshire, Langshan, Brahma
  • Layer: Leghorn, Plymouth Rock, Minorca, Ancona, New Hampshire
• Genetic Traits

  • At least 30 traits
  • Including: behavioral traits, welfare, sustainability
• Strains


  Developed to focus on specific genetic traits
• Production performance standards continuously vary and change
• Genetic trait selection

  1. DNA marker assisted selection

  2. Genomic selection of SNPs

  3. Done by poultry breeding companies
• Companies focus on specific traits which also include welfare and behavior of chickens, not only production traits
• Chicken Strains

  • Broiler: Cobb, Aviagen brands: Ross, Rowan Range, Arbor Acres, Indian River
  • Layer: Hi-line, Lohmann, Dekalb, Isa white, Isa Brown, H&N
• Broiler Strains: Cobb, Aviagen brands: Ross, Rowan Range, Arbor Acres, Indian River
• Layer Strains: Hi-line, Lohmann, Dekalb, Isa white, Isa Brown, H&N
• research line not bred extensively

  Experimental line
• cross of 2 or more experimental lines (hybrid vigor) required to form a pedigree line

  Synthetic line
• pure line with high genetic level

  Pedigree (elite) generation
• pure line between Pedigree and GP

  Great grand parent (GGP)
• pure line below GGP & PS

  Grand parent (GP)
• boiler breeder or commercial layers from GPs (male vs female

  lines) and is a product of 2-way genetic cross

  Parent stock (PS)
• This refers to the age at which hens start laying eggs. The aim is to have a uniform flock begin production at around 18-19 weeks of age, with peak egg production occurring at 24 weeks. Uniformity in onset of production allows for efficient management of the flock.


  Age at onset of production
• This metric measures the efficiency of egg production by calculating the number of eggs produced relative to the initial population of hens. It helps assess the productivity of the flock and the effectiveness of management practices.

  Hen Housed
• Capitalization in poultry farming refers to achieving maximum egg production at the lowest possible cost. It involves optimizing feed, housing, and other resources to maximize profitability while maintaining high production levels.


  Capitalization
• measures the number of eggs produced per day of production. It provides a daily snapshot of the flock's productivity and helps monitor changes in egg production over time.

  Hen day production
• refers to the weight of eggs produced per hen. It is an important metric for assessing the overall productivity of the flock and the quality of the eggs produced.

  Egg Mass
• nfluence egg size and feed requirements. Larger hens tend to produce larger eggs and may have higher feed requirements. Managing body weight and frame size is essential for optimizing egg production and feed efficiency.

  Body Weight / Frame
• refers to the ability of hens to maintain high levels of egg production over time. A persistent laying pattern, with 90% Hen-day production maintained at over 60 weeks of age, indicates good flock performance and management.

  Persistency of Egg Production
• measures the amount of feed required to produce eggs. A lower feed conversion ratio (FCR) indicates better feed efficiency. Good average layer FCR is around 2.1, and efficient feed utilization is associated with improved bird health and profitability.

  Feed Efficiency
• encompasses various factors such as shell strength, color, smoothness, and shape. It is influenced by environmental factors, nutrition, and hen health. High-quality eggshells are essential for egg handling, storage, and consumer satisfaction.

  Egg-Shell Quality
• includes factors such as Haugh unit (a measure of egg white thickness), egg solid yield, blood spots, and meat spots. These traits affect egg appearance, shelf life, and suitability for different processing methods.

  internal quality
• Other traits may include specific characteristics related to egg odor, such as the ability to produce trimethylamine (TMA) oxidase. Controlling egg odor is important for consumer acceptance and product quality.
• Temperament and welfare traits relate to the behavior and well-being of the birds. Genetic lines favorably predisposed to various housing systems exhibit traits such as reduced cannibalism, pecking, nervousness, and delayed egg production. Promoting positive welfare outcomes contributes to overall flock health and productivity.
• Blood spots are small, red spots or streaks found on the surface of the egg yolk. They result from the rupture of blood vessels during the egg formation process within the hen's reproductive tract. Blood spots are usually harmless and do not indicate any health concerns. However, they are considered undesirable in commercial egg production because they can affect the aesthetic appearance of the egg and may lead to consumer rejection. Blood spots are more common in brown-shelled eggs but can also occur in white-shelled eggs, albeit less frequently.
• Meat spots are irregularly shaped, dark-colored spots or particles found within the egg white or yolk. They are composed of tissue residues, such as small pieces of the reproductive tract or ovary, that mistakenly become incorporated into the egg during formation. Meat spots are also harmless from a health perspective but are considered aesthetically unappealing and can reduce the overall quality of the egg. Like blood spots, meat spots are undesirable in commercial egg production and can lead to consumer dissatisfaction if present in eggs sold for consumption.