SPRING SUMMER BONUS MAGAZINE 2026

2.2 Combined effects Any of or a combination of the above factors has a synergistic effect on the growth uniformity of the hens, which results in poor uniformity of the hens at the point of lay. 3. The house record card before lay Flock weight monitoring and health history are more than routine records, important elements of a performance forecast. 3.1 What rearing data tells you Consistent body weight tracking during rearing reveals whether birds are developing uniformly and reaching breed standards. Hens that grow slightly above the standard curve without becoming overweight typically enter lay with stronger body reserves. The result is stable production and eggs that consistently fall within correct grading categories. 3.2 Risks of poor or inconsistent recordkeeping Bird performance in laying cannot be guaranteed, and most commonly, flocks with uneven growth or birds falling below standard weight and development often struggle with delayed and uneven onset of lay. This leads to a wide spread of egg sizes, particularly an increase in small and rejected eggs. 3.3 A detailed house card A well-managed rearing farm should provide: • Weekly body weight records • Weight distribution and coefficient of variation (see figure 1) • A complete health history (including vaccinations) • The lighting programme up to 16 weeks and beyond These are not just records; they are tools that allow producers to predict grading outcomes and adjust management before problems arise. 4. Pullet development and uniformity in practice Figures 1 and 2 show a typical example of a flock that was fed a De Heus Excel Layer range from starter, grower, and developer at rearing. This flock was consistently above minimum breed standards while maintaining excellent uniformity of above 90% at 15 weeks (Figure 1). Figure 2 shows a positive and consistent rearing performance, with body weights tracking above the minimum standard and close to breed targets from around 6 weeks onward. 4.1 Early rearing phase During the first 4 weeks, birds started slightly below target, but recovered quickly by week 6. This indicates good brooding management and effective early correction. From weeks 6 to 12, growth remained steady and consistent, suggesting strong rearing management conditions such as: • Good feed intake • Adequate feeder space • Stable environmental conditions • Strong flock health 4.2 Late rearing phase During the developer period (12 to 16 weeks), birds continued tracking above minimum standards without becoming overweight. This supports uniform sexual maturity and controlled egg size development, which are key for consistent egg grading. Such growth patterns typically result in synchronised onset of lay and a tighter egg size Fig. 1: Example of weight distribution to show flock uniformity Fig. 2: Growth curve of Hyline Silver Pullets at Farm X (KZN, South Africa) www.agribonus.co.za Spring/Summer 2026 BONUS 149