What are the main causes of hair cracks (micro-cracks) in brown eggshells?

Hair cracks, or micro-cracks, are incredibly problematic in commercial brown egg trading as they often go unnoticed without professional candling but cause significant economic losses. As brown layer hens (like Lohmann Brown) age beyond 60 weeks, their ability to absorb calcium from their diet decreases, while the average egg size increases, resulting in a naturally thinner eggshell. Environmental heat stress (temperatures above 32°C) also causes hyperventilation, which reduces blood bicarbonate levels and depletes the calcium carbonate available for shell formation. Additionally, mechanical stresses in automatic collection belts, sorting tables, and transport crates can introduce fine hairline fractures. Wholesalers on Murghi Mandi discount cracked batches due to the high risk of breakage and Salmonella contamination. Farmers can prevent these issues by checking daily raw feed material rates on Poultry Rates, sourcing calcium pre-mixes on Poultry Plaza, and studying diagnostic guides in the Poultry Encyclopedia.