because of its ability to form a
compound with micronutrients such
as iron and zinc.
Microbial-derived phytase
that can be added to the diet of
pigs and poultry is produced on
a commercial scale as part of the
large feed enzyme market because
the exogenous phytase provides an
effective means of breaking down
the phytate in plant-derived feeds,
allowing the animals to use more
P and other minerals and proteins,
rather than excreting them.
Good precedents
By using a careful balance of
nutrients combined with phytase
(together with other measures), the
livestock industry in the Netherlands
has managed to halve the amount of
P excreted by growing and finishing
pigs over the past 20 years.
Taking the UK, which currently has
some 500,000 sows, as an example,
the consortium’s spokesman pointed
out that wheat could constitute up to
60% of the country’s pig and poultry
diets.
A variety of HAP wheat with
similar performance characteristics
to conventional wheat would
ensure that the entire requirement
in the diet of monogastrics was
met without the need to add
supplementary phosphate.
Ideally, it was hoped that the
new HAP wheat could also be used
in conjunction with commercially
produced phytase to further reduce the
release of P into the environment, since
there was evidence to suggest that they
could interact in a positive way.
The project aims to provide adapted germplasm and tools for marker-assisted breeding of
Highly Available Phosphate (HAP) wheat with the potential to significantly reduce diffuse
P pollution when used in pig and poultry diets. NIAB has recently invested £ 1. 25 million in
laboratory facilities, equipment and growth rooms specifically for the pre-breeding and
plant genetic research scientists.
Encouraging results
In fact, initial stages of this
research project have already
revealed the expected potential
reduction possible in diffuse P
pollution from HAP wheat is in line
with that demonstrated for HAP
maize and barley. Pigs fed with the
HAP maize reduced P excretion by
18% and by 16% when they were fed
with HAP barley.
In collaboration with the
University of Idaho, researchers at
NIAB have already been successful in
developing several new wheat lines
in which phytic acid P represents
only 42% of seed total P, compared
with 74.7% of seed total P in the
spring-sown control.
This has resulted in a significant
increase (more than 35%) in the
amount of phosphate that is
available to a monogastric animal —
and it is anticipated that this will lead
to a major reduction in input costs
and the environmental impact.
