Approximately half of discarded eggs in poultry farming are due to shell quality issues, impacting farmer profitability and consumer availability. Factors like genetics, bird health, nutrition, and handling significantly influence eggshell integrity, as highlighted by Mrs. Kasendi Mutinda, a Kenyan farmer who collects 12 crates of eggs daily from her 500 layers.

• 20-30 percent of shell quality variation is genetic, with older birds producing larger eggs with thinner shells.
• Diseases such as infectious bronchitis (IBV) and Egg Drop Syndrome (EDS) can severely damage oviducts, leading to poor eggshell formation; however, full vaccination can mitigate these risks.
• Nutritional deficiencies, especially in calcium, Vitamin D3, Zinc, Manganese, and Copper, contribute to soft or fragile shells.
• Improper handling, infrequent collection (recommended 3-5 times a day), and high temperatures (above 20 degrees Celsius) during storage weaken eggshells and increase contamination risks.