Feed Strategy - June 2018 - 22
22 ❙ FeedStrategy
BROILER SUPER PRE-STARTERS
are heat liable, and this is why we feed thermally processed
soybeans and not just plain raw soybeans to all monogastric
animals, such as the broiler. Nevertheless, not all ANF are heat
liable, and not all are destroyed by the usual heat treatment
of normal soybean meal and even extruded full-fat soybeans
(because excessive heating reduces protein digestibility by the
formation of Maillard reaction compounds). Some small, but
apparently signiﬁcant quantities, remain intact, and this fact
has caused nutritionists to restrict or even avoid the use of soybean protein sources in diets for weaned mammals; could the
same be true for post-hatch chicks?
Of course, it is possible to obtain soybean protein virtually free of ANF, such as in soy protein isolate - the
form of soy protein used in human nutrition supplements.
However, such products remain cost-prohibitive and even
unavailable for commercial animal feeds. Soy protein
concentrate is another alternative that contains minimal
ANF, but again cost remains high, and we must keep in
mind that broiler production is a low-cost/input enterprise.
Thus, these largely puriﬁed forms of soybean protein remain rather inaccessible for our purposes.
its own problems, in addition to being prohibitively expensive at the required high quality.
Enzymes and soybean meal
I have long advocated among the enzyme and probiotic
manufacturers the possibility of treating raw soybeans
with an enzyme or a cocktail of enzymes to neutralize the
ANF of soybeans, most of which are proteins. Perhaps this
remains unrealistic for current technology levels, as not all
ANF are proteins, and of course a cocktail of enzymes for
all ANF could be cost-prohibitive for commercial purposes.
Another approach could be that these enzymes are produced by probiotics (microbes or yeasts) designed speciﬁcally for this purpose, but inside the animal gut. According
to some experts in this ﬁeld, such an approach is possible
from a technical point of view, but it would require some
signiﬁcant genetic engineering that would create a GMO
type of probiotic - something frowned upon by several regions in the world. And, of course, we have the issue of cost
of developing such a superbug that would target all ANF.
Commercial proteases are available to be included
PERHAPS TREATING THE SHORT-TERM PROBLEM is less costly, but
when one considers the lifetime performance of a modern broiler, it is
doubtful if we can still afford to lose days of growth potential.
The same can be said for most highly digestible proteins, be it from animal or vegetable origin. Not many
years ago, most if not all broiler diets contained 5 to 10
percent high-quality ﬁsh meal. When ﬁsh meal became
so expensive as to exclude itself from feed formulations, poultry nutritionists resisted its removal until
the last possible moment. Even today, some quality ﬁsh
meal products are used in broiler diets - especially in
the ﬁ rst diet post-hatch - perhaps because we need to
reduce the ANF contributed by soybean meal through
reducing its inclusion rate. Nevertheless, ﬁsh meal has
in the broiler feed, and evidence indicates a minimal
increase in digestibility (2 to 5 percent). Is this because
these proteases increase protein digestibility, or because
they reduce the negative effect of ANF on innate protein
digestibility? Whatever the real mode of action - most
likely a combination of the two - the fact remains that
enzymes have a role to play in feeding broilers a more
suitable form of soybean protein.
And, ﬁnally, we should not forget the readily prepared
soybean meal, already treated with enzymes, that is outside the animal. Such products appear to be at least as
www.WATTAgNet.com ❙ June 2018