In conclusion, there are 4 factors: grinding, conditioning, pelleting and feed formulation. Amongst these factors, grinding of raw materials and conditioning of feed are regards as the most influential factors affecting pellet durability.
Grinding of Raw Materials
There are several benefits of grinding raw materials. It improves uniformity of mixing, increases absorption of steam and increases digestibility of feed. In the light of pellet quality, grinding of raw materials reduces the amount of large particles which can reduce pellet strength. It also increases surface area for feed particles to adhere. That is to say a finer, even grind can result in better pellet quality. If the particle of feed is larger in the ration, it will need more time for heat to permeate to the core of the feed particle. This is a factor which must be taken into consideration when engineering the conditioner to gain a specific amount of retention time. In all, in order to achieve better feed pellet durability, grinding needs to provide a fine, even grist.
In addition to grinding of raw materials, conditioning is one of the most important factors in achieving good poultry feed pellet quality. Conditioning creates thermal, chemical and mechanical energy, the steam used during conditioning disrupts the structure of the starch and causes gelatinization and also plasticizes proteins and soften fibers.
Besides grinding and conditioning, the actual pelleting process has an influence on pellet quality too. Meal should enter the feed pellet machine correctly conditioned as this will aid shaping the meal into pellets rather than cooking the meal via friction heat at the die. Excess friction heat in the die can produce a hard brittle pellet rather than a durable one; also conditioning the meal in the conditioning vessel is more cost-efficient than in the feed pellet mill.
The ingredient formulation is also of extreme importance to the feed pelleting process. Feed formulation is the process of quantifying the amounts of feed ingredients that need to be put together, to form a single uniform mixture for poultry that supplies all of their nutrient requirements. Different ingredients have different levels of conditioning to achieve optimum gelatinization.