Problems Encountered during Feed Milling in Tropics

Feed processing is becoming a more challenging task than ever with coming newer raw materials and technologies, and growing advance research to control increasing feed cost. Ignorance about the feed processing in tropics is making these challenges more intense. There is a need of deep knowledge about the three aspects of feed milling including feed chemistry, feed engineering, and nutrition.

Feed mills are facing various issues, some of these are listed below:

  • Poor production efficiency i.e. increased cost per MT pellet
  • Poor moistening of meal in the conditioner
  • Wrong selection of conditioners (mostly short time conditioners)
  • Poor steam management – poor maintenance of broiler, steam pipeline, PRV, steam inlets position and design
  • Excessively dried ingredients, forming dry and hard pellets which results in reduced feed intake
  • Poor digestibility of feed and wet litter problem
  • Moisture loss after pelleting process causes 1-3% 
of moisture shrink. (0.5% moisture shrink is worth USD 9 at today’s feed cost )
  • Reduce die life adding replacement 
  • Poor pellet quality which affects growth performance
  • Problem of “fines”, the analysis shows that most of the fat, minerals like Ca and P, and micro minerals like Zn are present in these fines
  • Lack of proper training to mill operators

In this sub-continent nutrient loss during feed processing is another silent issue, as the miller first wants to address various physical issues of pelleting. Some of issues include:
Damage and wastage of nutrients like vitamins, amino acids & enzymes

  • Poor feeding value due to improper cooking of starch which affects digestibility and available energy value
  • Over compensation of nutrient and energy in the feed formulation
  • Poor feed processing which affects immunity and growth performance of poultry
  • Increased medication cost at farm level

Loss of nutrient value in processed feed

Poor steam conditioning end up in a badly hydrolyzed mash resulting in difficulties at the press. Pushing poor hydrolysed and conditioned mash through the die is like “roasting” the meal, which result in maillard reaction (amino acid reacting with reducing sugar from the friction heat) and dextrinization (burnt to a certain extent via thick die passage). These problems are more noticeable with the use of thicker die (for a high die compression rate). During the passage of poor hydrolyzed meal through the die, temperature inside the die holes reach around 160° Celsius which degrades (or destroys) many enzymes and vital nutrients in fraction of seconds. This has a detrimental impact on livestock immune, health, and productivity.

Now, the major concern is increasing trend of producing broilers without using AGPs (antibiotic growth promoters), where Europe is leading the way. The continent is encouraging supplements which are comparatively expensive, new generation alternative feed additives like secondary plant compound products, probiotics, prebiotics, organic acids, and enzymes (claiming its wide use in Europe), as a replacements to AGPs, but are they being processed correctly?

Feed processing in right manner

Poor mash hydrolyzation in the conditioner, poor steam management, and insufficient conditioning time greatly affect starch cooking. While amylase enzyme can digest gelatinized starch much better in the gut, and hence enhancing the energy value. But nutritionist can also lower energy value in feed formulation, if they understand how to cook raw starch effectively.
The main objective of feed pelleting is well cooked raw starch (especially the amylose fraction which provides the gelling effect), to achieve high degree of starch gelatinisation resulting in good intra-particles bonding and excellent feeding value. However, due to the lack of understanding about raw starch cooking in a dry medium, the industry is not able to manage well cooking of raw starch which finally affects feed production efficiency as well as quality of produced feed.
To address this issue, a methodological approach is developed to manage various parameters in tropical feed pelleting process, which contributes to the effective mash hydration. For effective raw starch cooking these parameters need to be addressed:

  • Compounded mash temperature in tropics ranges from 38°C to 44°C. It causes a setback 
in steam/mash interaction and moisture transfer from steam
  • Managing mash moisture before and after steam conditioning
  • Steam management
  • Steam temperature and steam volume deployed in the conditioner
  • Sufficient conditioning residence time

Water added in the mixer and water from the condensing steam in the conditioner must be effectively hydrolyzed (infused) in the mash.
Feed industry is losing lot of money without even realizing about the wastage of nutrient value of a well formulated feed due to poor feed processing and inefficient cooked starch. Adding more cost to mask the problems is not the right answer to face future challenges of feed processing.
It is high time to understand the importance of feed processing in producing quality pellet with all nutrients intact and hence better livestock performance. A large feed mill (especially those integrated with livestock operation) can save back multi-million using these facts.
For more information please contact Dr. Naveen at