SPRING SUMMER BONUS MAGAZINE 2026

Same house, same feed. Why don’t your eggs grade the same? Mlungisi Gwala - Technical Advisor: Poultry In commercial egg production, profitability depends heavily on howmany eggs fall into premiumgrading categories. Yet many producers face a frustrating reality: birds in the same house, under the samemanagement, produce eggs of vastly different sizes. The root cause is often not nutrition or genetics, but poor flock uniformity at transfer. What happens during rearing ultimately determines whether your eggs grade consistently or cost you money. 1. Uniformbirds, uniform eggs = the foundation of profitability Flock uniformity measures how closely birds match the target body weight for their age. Ex- pressed as the percentage of birds within +/-10% of the average body weight, a good flock should achieve at least 85% uniformity or higher at transfer. 2. Why does this matter? Uniform birds respond to light at the same time, reach the onset of laying together, and produce eggs of similar size, while non-uniform birds do the opposite, resulting in mixed egg sizes, inefficient grading, and lost income. 2.1 Factors affecting bird uniformity and egg grading Factor How it affects flock uniformity Impact on production Housing Poor brooding conditions create different environmental zones and early growth gaps that never fully recover. Uneven bird development and inconsistent egg sizes Feed competition Limited feeder space allows dominant birds to thrive while weaker birds fall behind. Increased body weight variation and poor uniformity Inconsistent feed quality Variations in nutrients or particle size result in uneven intake and growth. Irregular maturity and egg size distribution Water issues Uneven access or pressure differences quietly affect flock performance. Reduced feed intake and uneven growth Stocking density Crowding increases stress and competition. Lower uniformity and delayed onset of lay Health challenges Even mild or uneven disease pressure creates growth variability. Poor performance and inconsistent egg grading Table 1: Compares features of different mineral sources (inorganic vs organic) Spring/Summer 2026 BONUS www.agribonus.co.za 148