Role of Moisture Control in Feed Processing

Pellet quality and efficient functioning of machinery are the key factors for any feed miller. Providing ideal features for proper conditioning is the determining factor for achieving improved pellet quality as well as machine efficiency.
Effective conditioning and pelleting is a complex matter that needs to address issues like, delivering ample moisture to the conditioner, and providing sufficient moisture to the feed particles during conditioning process. Hence, it is required to understand the factors that cause poor conditioning and pelleting and having its effect on machine performance.
Moisture management in feed is the key from an economic and feed quality point of view. The amount of moisture in bound form, brought by macro ingredient like corn, in a feed formula contributes to the production efficiency. More is the moisture in compounded feed, more it can assist cooking and conditioning, providing also better machine efficiency (higher throughput at lower energy consumption), pellet quality, and feeding value (enhanced nutrient value).
The process can be defined by “Food Polymer Science”, phenomenon of polymerization of starch or protein structure in relation to moisture content during feed formulation and processing. Water can act as a plasticizer medium contributing to the formation and stability of polymeric carbohydrates and proteins, which results in pellet formation and improved feeding value. Then, the pellet feed sample can be tested for different aspects such as degree of gelatinization (DSC method), water activity, and moisture content etc to ensure the degree of cooking for required feed quality.
Kinetics of heat / moisture / steam application in feed processing and quality deterioration present a complete new dimension for the cost reduction during feed formulation process, which does not depend only on the raw material cost but on the efficient production to enhance the feeding value for better animal performance.
A sufficient moisture level is important as it reduces the energy usage during the pelleting process, and also ensures that production runs more smoothly by lowering the risk of blockages. This is important for preventing nutrient losses as a result of excessive heat production. Furthermore, it guarantees good pellet quality as an optimal moisture level is known to positively affect pellet hardness.
Feed cost reduction can also be achieved by saving the lost nutrients of grain during storage, and potentially tapping the opportunity to reduce formulation specs. It is possible to lower the energy value to some extent in a feed formulation by compensating it with improved cooking/gelatinization that invariably contribute to more digestible energy for the animal.

Dr Naveen Kumar, Delst Asia