FOOD week 4 Egg Quality, Spoilage, Saftety and Management

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Questions and Answers

Which breed of chicken is favored by commercial egg producers in Australia?

ISA Brown

HyLine Brown (correct)

Hi-Sex Brown

HyLine White

What percentage of an avian egg is comprised of albumen?

52-58% (correct)

9-14%

32-35%

17%

Which component of egg yolks has been shown to potentially prevent atherosclerosis?

Phosvitin

Protein

Liposoluble glycoproteins (correct)

Lipid

What is the average protein content of a medium-size egg?

6.4 grams Signup and view all the answers

What is the main function of the waxy hydrophobic, proteinaceous layer on an eggshell?

To act as a mechanical barrier Signup and view all the answers

Which of the following is true about egg consumption in ancient humans?

Carbon dating of middens shows evidence of human consumption of ostrich eggs between 119,900 and 60,000 years ago Signup and view all the answers

Which of the following is NOT a factor that can damage the cuticle of an egg?

Immediate hardening of the cuticle Signup and view all the answers

What is the purpose of the lysozyme, avidin, and protease inhibitors found in egg white?

To inhibit the growth of microorganisms Signup and view all the answers

Which technology is used to detect internal defects in eggs?

Automatic candling Signup and view all the answers

What is the Haugh unit a measure of?

Egg quality based on albumen height Signup and view all the answers

Which environmental factor can reduce egg quality and increase the risk of Salmonella contamination?

Heat stress Signup and view all the answers

Which of the following is NOT a factor affecting egg production?

Genetic selection Signup and view all the answers

What is the major route for disease/pathogen transmission in poultry?

Transfer between production areas Signup and view all the answers

What is the main concern driving welfare considerations in the egg industry?

Consumer perception Signup and view all the answers

Which disease has been detected in poultry egg facilities in NSW and Victoria?

Salmonella Enteritidis Signup and view all the answers

What is the main method mentioned to safeguard egg production and the supply chain?

Improved vaccination programs Signup and view all the answers

Which disease can cause big liver and spleen in chickens?

Big Liver and Spleen Disease Signup and view all the answers

Which disease is caused by bacteria and can result in sticky eyes and respiratory symptoms in chickens?

Fowl Cholera Signup and view all the answers

Which disease is caused by parasites and can lead to weight loss and poor growth in chickens?

Round worms Signup and view all the answers

Which disease is caused by a virus and can result in tumors in chickens?

Marek’s Disease Virus Signup and view all the answers

Which of the following statements about ancient Egyptian food sources is true?

There is evidence of chickens being consumed in ancient Egypt before the New Kingdom Signup and view all the answers

What was the average number of eggs laid per year by hens in the 1900s?

80-150 eggs Signup and view all the answers

When did intensive egg production, with commercial farms housing 500,000 hens, get introduced?

1930-1950 Signup and view all the answers

What is the current trend in Australia regarding caged hen production?

Caged hen production is being phased out by 2036 Signup and view all the answers

What is the impact of free-range farming on chicken productivity, mortality, health, and welfare compared to conventional farms?

Free-range farming has lower productivity and higher mortality compared to conventional farms Signup and view all the answers

Study Notes

Chicken Breeds and Egg Production

The layer hens favored by commercial egg producers in Australia are typically White Leghorns.

Egg Composition

Albumen constitutes about 60% of an avian egg.
Egg yolks contain components like phospholipids, which have been shown to potentially prevent atherosclerosis.

Nutritional Facts

The average protein content of a medium-sized egg is around 6 grams.
The waxy hydrophobic, proteinaceous layer on an eggshell serves to protect the egg's contents from contamination.

Egg Consumption and History

Ancient humans consumed eggs as a valuable food source due to their high nutritional value.
Damaging factors for the cuticle of an egg include physical impacts, chemical exposure, and temperature variations; however, egg color does not affect cuticle integrity.

Egg Chemistry and Safety

Lysozyme, avidin, and protease inhibitors found in egg whites have roles in protecting against bacterial infection and preserving egg freshness.
Candling technology detects internal defects in eggs by examining the eggs' contents using light.

Quality Measures

The Haugh unit measures egg quality based on the height of the egg white, which correlates to freshness.
Environmental factors such as temperature extremes can reduce egg quality and increase the risk of Salmonella contamination.

Production and Welfare

Factors affecting egg production include hen age, health, and breeding, but housing density is not a direct factor.
The primary route for disease and pathogen transmission in poultry is through contamination of feed and water.
The main concern driving welfare considerations in the egg industry is the ethical treatment of hens and their living conditions.

Diseases in Poultry

Avian influenza has been detected in poultry egg facilities in NSW and Victoria.
Biosecurity measures are critical for safeguarding egg production and the supply chain from disease.
Newcastle disease can cause enlarged liver and spleen in chickens, while infectious coryza, caused by bacteria, leads to symptoms like sticky eyes and respiratory issues.
Coccidiosis, caused by parasites, results in weight loss and poor growth, while Marek's disease can lead to tumors in chickens.

Historical Context and Production Trends

Ancient Egyptians utilized various food sources, including eggs.
In the early 1900s, the average number of eggs laid per year by hens was about 120.
Intensive egg production, with commercial farms housing 500,000 hens, was introduced in the late 20th century.
In Australia, there is a current trend towards reducing caged hen production in favor of free-range methods.
Free-range farming impacts chicken productivity, mortality, health, and welfare positively compared to conventional farming systems.

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Description

Test your knowledge on the defence mechanism of avian eggs. Learn about the factors that can damage the cuticle and make it permeable, such as washing and bacterial enzymes. Discover how cooling and post-laying processes can create a vacuum that allows air and microbes to enter through the pores.