Chin Sou Fei
Novus International Pte Ltd
The daily ration of nutrients that an animal receives from a feed may vary from time to time due to a
number of reasons. The sources of variation will probably cause variation in the day-to-day level of
nutrition received by an individual animal. Certain nutrients are guaranteed to be present at minimum
levels and regulatory officials will be concerned, if guarantees are not met. Certain ingredients may
be toxic at very high levels. The nutrient variation in feeds is most likely to occur for the following
reasons (Wilcox and Balding, 1976):
a. Variation in the composition or quality of ingredients from batch to batch or from time to time
b. Poor mixing or segregation after mixing
c. Errors during weighing or proportioning
In most cases, a sound quality control program can insure optimum feed preparation. Routine
inspection of the mixer, proper mixer "tuning" , maintenance of all liquid systems and close attention
to ingredient inventories will go a long way to ensure that the nutrient specifications prescribed by
the nutritionist, actually reach the bird.
The consequences of nutrient level variation are varied. However, the major disadvantage of variation
is normally the effect on animal performance.
Mixing is one of the most essential and critical operations in the process of feed manufacturing, yet
it is frequently given little consideration. The objective in mixing is to create a completely homogeneous
blend. In other words, every sample taken should be identical in nutrient content. A functional definition
of uniform mixing can be summarized in one sentence. "All nutrients will be present in sufficient
quantity in the daily feed intake of the target animal to meet its minimum growth requirementsa€?a€?.
The literature is filled with classic examples of the impact of inadequate vitamin and mineral consumption
on animal performance. However, field examples are rarely "classic" in nature, and are therefore, very
difficult to diagnose. Unfortunately, in most cases the effect of inadequately/ improperly mixed feed
manifests itself as marginally depressed performance. Typically, birds exhibit slight reductions in
growth, feed conversion, feathering and other performance parameters. As a result, the technical
staff of a commercial company may incorrectly diagnose a decease condition, and never resolve the
underlying problem in the mill.