إنتاج الدواجن: الكفاءة والوراثة

• The primary goal of poultry production is converting feed into high-value nutrients (meat and eggs) suitable for human consumption.
• Feed represents 60-70% of the total costs in meat or egg production, making improved feed efficiency crucial.
• In the 1950s, chicken meat production was secondary to egg production. Today, it is a primary source of meat.

Chicken Breeds

• Laying hens are often slaughtered after their laying period, providing meat.
• Other poultry like turkeys, ducks, geese, quail, and rabbits are raised solely for meat. Their egg production is limited to reproduction.
• Modern meat poultry production relies on genetically superior birds with rapid growth and efficient feed conversion.
• Geneticists crossbreed native chicken breeds, creating commercial meat hybrids efficient at converting feed to meat quickly.
• Some hybrids can reach 2 kg live weight in 7 weeks, consuming 1.4 kg feed per kg of live weight.
• Broiler production depends on exploiting hybrid vigor (heterosis) from crossing diverse breeds.

Types of Hybrids

• Single two-way crosses: offspring of two different purebred lines.
• Three-way crosses: Created by crossing a two-way hybrid female with a male from another line.
• Four-way crosses: Result from crossing two different two-way hybrids.
• Three-way and four-way hybrids are preferred for commercial meat hybrids due to their uniformity in growth.
• Creating four-way hybrids involves five steps.

Four-Way Hybrid Development

• Step 1: Develop pure, separate lines of native breeds known to contribute desired traits. This involves intensive inbreeding with strong selection for traits like growth rate, feathering, and meat quality.
• Step 2: Conduct multiple two-way crosses between family lines, testing offspring to identify individuals with high compatibility, indicated by superior performance compared to their parents.
• Step 3: Maintain outstanding families in a pure form as foundation stock for commercial hybrids, being able to capitalize on their power for years to come. Companies keep these originals very closely guarded, hence they are often internally referred to using numbers or the company owner's name.
• Step 4: Select founding stock to create "grandparent" generation hybrids. One hybrid functions as parents to the commercial hybrid, the other as mothers. All mothers provide +100 chicks per laying. Plymouth Rock hens are used as mothers, Cornish hens are used as fathers.
• Step 5: The process involves conducting crosses between the parental generations to produce commercial meat hybrids i.e. "broilers". It ends after the poultry is raised to 7 weeks.

Factors Affecting Meat Production

• Genetics, feed efficiency, growth rate, and carcass characteristics influence meat production.
• Genetics affects the nutritional aspects through high growth rates, early feathering, high resistance to diseases. Carcass qualities include a good shape matching breed standards and high levels of nutrients.
• Diet impacts nutritional status.
• The conditions in which the poultry are raised affects their health, requiring strict maintenance and environmental regulations from farmers.

Genetic and Related Factors Influencing Growth Rate

• Genetics: Growth is a polygenic trait. Crossing relatively heavy birds with one having lighter characteristics results in an average bird. The heritability factor of development can range between 60 an 70%. Hybrid breeds commonly mix local types of chickens with those that are more developed in size etc. to improve on the blend.
• Internal breeding reduces poultry size. To increase profitability for breeders, crossbreeds are vital to exploit heterosis.
• Egg Size: Larger eggs produce larger chicks.
• Gender: Males grow faster and have more muscle mass.
• Thyroid Activity: Higher thyroid function increases growth rate.
• Feathering Rate: Faster feathering correlates with faster growth.
• Feed Conversion Efficiency: Efficient feed conversion leads to faster growth.

Measuring Growth Rate

• Growth rate is assessed by tracking an individual's weight over time at set dates, determining if the weight is on track with standard conditions.
• The ratio can be calculated through the following ratio: (Final Weight - Initial Weight) / ((Initial Weight + Final Weight) / 2). Multiply the result by 100 to find growth rate.
• Early growth is more profitable.
• High initial growth is the most important for growth. This declines at the 12-16 week mark depending on incubation.

Additional Characteristics

• Keel Length: Longer keel bones are linked with increased volume of meat on the front
• Leg shape can also infer growth rate.

More Factors Affecting Growth

• A bird's ability to convert feed to meat is affected by genetics. Crossing different breeds is vital to produce offspring that take qualities from each of the parents.
• The proper preparation of hen's food supply can affect the nutrition provided to the yolk. Protein levels are vital to chicks as they age.
• The time of the year also affects the chicken's capacity to grow. The high temperatures throughout the summer lower the bird's ability to eat as the food is less appealing.
• The facilities in which they are grown is vital to the safety of the chicks. An area free of germs that is spacious helps make the conditions suitable.

Feed Efficiency

• Feed efficiency is important for profitability.
• It depends on how well the animal's body functions and is a hereditary trait.
• The ratio is measured to be +1kg of organic material per +4kg of the bird i.e. 4:1 on average.

Feather Quality

• The feather quality, the result of the hereditary factors of the bird, affect a hen's ability to clean its feathers - which can decline it's ability to be sold.
• Having a balanced diet increases feather quality.
• Birds with lower standards tend to create less feathers.
• To assess feathers, assess wing feathers by inspecting the number of primary feathers growing at a 5-7 ratio. Additionally, count secondary feathers to measure growth.
• Check the tail feathers after one week.
• Back feathers reflect growth up to 4 weeks after incubation.

Bird size

• The amount of muscle a chicken contains has a large impact on the quality of the meat. To improve muscle mass: increasing the number of cells, and increasing the size of individual cells.
• Hereditary factors affecting the bird's characteristics is also essential.
• The shape of the bird also has consequences on its value: the most appealing birds are wide between rib-cages and have round thighs and lower body.

Meat and Body Characteristics

• Body composition refers to parameters of blood volume and other measures.
• Mixing breeds is vital to increasing meat in birds. The bigger meat, the more the chickens are sold.
• The food of high quality and organic matter improves their flavour. The birds also must be of a young age to be well-liked.
• Meat color: Meat color has to have to be yellowish in order to draw customer's love, as well as the skin color has to be light. Additionally, muscle is often inspected to see the flavor and fat of the chicken meat. Muscle and taste are commonly looked for when inspecting meat.

Advantages of Broiler Production

• High Efficiency: Broilers efficiently convert feed to meat, with about 1 kg growth per 1.4 kg feed.
• Short Production Cycle: Broilers are ready for market in 42-49 days.
• Low Disease Risk: Their short life reduces disease exposure.
• Mechanization: Broiler production can be heavily mechanized.
• High Demand

Industry Guidance

• Select broiler breeds carefully
• Provide food with reasonable expenses
• Make it commonplace provide health services to hens in safe manners
• Increase organic means for growing hens
• Promote the product through social and monetary services