Feed Strategy - June 2018 - 37
FeedStrategy ❙ 37
Feed safety and animal health can be improved through feed processing. hedgehog94 | istock.com
Maximizing coating's potential
As feed formulators turn to feed additive alternatives
- probiotics, prebiotics, organic acids, enzymes, etc. -
to combat common pathogens in livestock production,
one must consider whether they will remain stable when
faced with severe processing temperatures.
"Moisture and temperature might accelerate sensitive ingredients in breaking down - which is exactly
what we don't want to happen," Lawson says.
It can be difficult to control this with certain types of
extrusion. However, livestock feed-specific extruders exist
that offer a shorter resonance time in the barrel as compared with conventional extruders. In short, a process that
exhibits an elevated temperature for a short time is utilized.
According to Lawson, fats and oils can be included
in the formulation by being pumped continually in the
pre-conditioner at levels up to 7 percent before noticing
a negative impact on pellet quality. This is due to the fact
that pellets are formed by agglomeration versus pressing
layer after layer of feed much like a pellet mill. Beyond
that, there is room for an additional 6 to 7 percent of fat/
oil absorption during atmospheric coating. The reason:
the pellet is "melting" into its final state, with the materials agglomerated into one piece versus several layers.
"By having an open, porous structure, it allows you
to post-coat with feed additives that may not survive
the extrusion process," Lawson says. "Now the enzymes, probiotics and other heat-sensitive ingredients
that you might not want to consider - or maybe overformulate if they are heat labile - can bind to the feed
and make it much more efficient."
"When we talk about producing feed without the
use of antibiotics, we still want to try to deliver the most
hygienic, pasteurized feed possible," Lawson says. "If
we are producing feed from anywhere from 100 to 140
degrees Celsius, we are definitely eliminating anything
that can be harmful to the flock or the herd." ■
References available upon request.
Editor's note: The 2018 FIAAP Animal Nutrition
Conference, co-located with VICTAM, was held in
Bangkok in March 2018.
How feed extrusion can improve digestibility, safety:
June 2018 ❙ www.WATTAgNet.com