HERFS/AUTUMN BONUS TYDSKRIF 2026

development of heavier gizzards, improved feed efficiency, and improved carcass yield in some cases. Another example of the importance of physical microstructure for digestion is the use of coarse limestone for layer hens. It takes the layer more time to digest and absorb the coarse limestone particles than the fine particles. Therefore, the digestion of coarse limestone particles results in a slow and steady release of calcium in the blood. This is beneficial because it takes a long time for the eggshell to be formed, during which a constant supply of calcium from the blood is needed. However, the finer particles of feed also contain very important nutrients, such as minerals and vitamins, and fine limestone is available to hens more quickly via faster digestion and absorption. Mash versus pellets versus crumbles: Which one to choose and why? Chicken feed can be presented in different physical macrostructures: mash, pellets, and crumbles. Pellets are eaten the fastest, mash the slowest, and crumble in between. The choice of feed structure is not only determined by chickens’ requirements, but also by market preferences, farmer requirements, production aim, availability of raw materials, local environmental conditions, availability of production technology, transport, and costs. The chicken species that are being farmed often determines the main choice for feed form. Layer hens need access to feed ad libitum, so a mash form is typically recommended to prevent excess weight gain. In contrast, broilers need to grow quickly to meet production parameters, and pellets are ideal to increase intakes. Mash feed Mash feed is produced by mixing and milling raw materials into a homogenous mash. Mash feed has lower production costs and coarser particles that improve digestion, with the microstructure primarily determined by the raw materials and production process when milling the feed. Important factors to consider with mash feed include the homogeneity and flowability of the feed (especially in silos and transport) and the limitation of dust (fine particles of < 0,5 mm) and extra-large particles (> 4 mm). Homogeneity of mash feed is much more important for transport in bulk than in bags. If the mash feed structure is not homogenous, it could potentially demix in the bulk truck during transport, and in the feeding system on the farm. Practically, a disadvantage of mash feed is the chance of selective feeding, where either the fine or coarse particles are eaten first. To prevent chickens from selectively feeding, it is important to check whether there are still enough coarse components in feed troughs 10 minutes after feeding. Components of different particle sizes should be evenly distributed throughout the feed troughs to prevent selection. The type of feeding system also has an impact; a fast-moving chain feeder can prevent hens at the front of the chain from selecting all the coarse components, while such prevention is much more difficult in manual feeding. Mash feed may be considered less hygienic as there is no heat treatment to kill bacteria. Feed intake and growth are also slower when feeding a mash compared to crumbles or pellets. However, the lower and more regulated feed intake of mash feed can be advantageous when it is necessary to slow down growth in growing pullets and broiler breeders. Pelleted feed Pelleted feed is produced by using pressure and steam to agglomerate mash into pellets. The pellet can be produced in different diameters and different lengths. www.agribonus.co.za Herfs/Autumn 2026 BONUS 29