HERFS/AUTUMN BONUS TYDSKRIF 2026

This system is gantry-fed, and provided that the gantry is functioning properly and uniformity is high, the feed should deplete at an even rate. Here, the uneven feed depletion may be due to a lack of uniformity across the shed. Alternatively, and possibly more likely, the uneven feed level may be due to the gantry distributing feed unevenly. Uneven feeding can lead to a decrease in uniformity as some hens are overfed and others are underfed. Overfed hens may become overweight and develop excessive fat pads that obstruct the reproductive tract, leading to laying complications; underfed hens may become underweight and struggle to meet their nutritional requirements and thus cease to lay. As uneven feeding continues, uniformity will worsen, and production will continue to suffer. A lack of uniformity also leads to the lighter hens losing more condition and the heavier hens just getting heavier. Within a caged system, it is natural for a cage hierarchy to form, whereby the bigger and/or more aggressive hens will bully the smaller or lighter hens; this is especially true for cage systems where stocking densities and feeder space do not allow for all the hens to feed at the same time. Large variances in uniformity will result in the smallest hens consistently being bullied away from the feeders. Conversely, when uniformity is high, and hens are a similar size, feed competition is more well-regulated and less of a hierarchal feeding structure is seen. While these factors are important during the laying period, they are even more crucial during the rearing period, where a lack of uniformity and thereby a lack of uniform feed intake will impact gut development, growth, and skeletal development. Sexual maturity and photo-stimulation Arguably, uniformity has the greatest impact on sexual maturity. Photo-stimulation should begin when hens reach the target weight and not necessarily the target age. When photo-stimulation begins, all hens, no matter their size, will begin to be stimulated to lay. If uniformity is low, some hens will not be at the target weight when stimulation begins. These hens will not respond to the stimulation and will come into production later, produce smaller eggs, have increased chances of prolapse and vent issues, as well as increased chances of mortality from laying complications. Signs of sexual maturity include well-developed, red combs and wattles. Figure 3 shows a small, pale, underdeveloped comb on the left and a larger, brighter, more developed comb on the right, indicating a lack of sexual uniformity within hens of the same age. Figure 4 displays the rough location of the pin bones; a sexually mature hen will have a space of at least three to four fingers between these pin bones, while an immature hen will have just enough space for one or fewer fingers as a point of measurement between her pin bones. Consequently, there will not be enough physical space for the immature hen to lay an egg. Figure 2: Variation in laying hen size and body weight Figure 3: Variations in comb development Figure 4: Schematic diagram of the rear of a laying hen www.agribonus.co.za Herfs/Autumn 2026 BONUS 129