Phytate is a natural dietary content and constitutes 0.4–6.4% (w/w) of most cereals and legumes (Eeckhout and Deaepe, 1994). It is poorly digestible for monogastric animals due to a lack of effective endogenous phytase (Bitar and Reinhold, 1972). Phytate acts as an antinutritional factor, exerting its effects via a reduction in the solubility, and availability of phosphorus (P), and to a lesser extent, Ca, Zn, Fe (Nävert et al., 1985; Hallberg et al., 1987; Hurrell et al., 2003). It was also reported that phytate could decrease the utilization of protein, amino acids and starch. It has been suggested that phytate may bind with starch either directly, via hydrogen bonds, or indirectly, via proteins associated with starch (Thompson, 1988; Rickard and Thompson, 1997). Phytate is also known to inhibit a number of digestive enzymes such as pepsin, alpha-amylase (Deshpande and Cheryan, 1984) and increase mucin secretion, excretion of endogenous minerals and amino acids in broiler chickens (Liu et al., 2008). Another issue is higher cost of dietary inorganic P which has been increased remarkably in last decade because of shortened phospate sources. Poultry industry has still been growing and reached huge mass production and contribution to environmental pollution has been heightened concerns because of the poor utilization of phytate phosphorus by poultry.

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Latest Experience with Phytase in Poultry
Prof. Necmettin Ceylan and Prof. brahim Ciftçi
Ankara University, Turkey
Phytate is a natural dietary content and constitutes 0.4–6.4% (w/w) of most cereals and
legumes (Eeckhout and Deaepe, 1994). It is poorly digestible for monogastric animals due to
a lack of effective endogenous phytase (Bitar and Reinhold, 1972). Phytate acts as an anti-
nutritional factor, exerting its effects via a reduction in the solubility, and availability of
phosphorus (P), and to a lesser extent, Ca, Zn, Fe (Nävert et al., 1985; Hallberg et al., 1987;
Hurrell et al., 2003). It was also reported that phytate could decrease the utilization of protein,
amino acids and starch. It has been suggested that phytate may bind with starch either
directly, via hydrogen bonds, or indirectly, via proteins associated with starch (Thompson,
1988; Rickard and Thompson, 1997). Phytate is also known to inhibit a number of digestive
enzymes such as pepsin, alpha-amylase (Deshpande and Cheryan, 1984) and increase mucin
secretion, excretion of endogenous minerals and amino acids in broiler chickens (Liu et al.,
2008). Another issue is higher cost of dietary inorganic P which has been increased
remarkably in last decade because of shortened phospate sources. Poultry industry has still
been growing and reached huge mass production and contribution to environmental pollution
has been heightened concerns because of the poor utilization of phytate phosphorus by
poultry.
As a solution of the problems related to phytate, the use of exogenous phytase in poultry diets
has found widespread scientific and commercial acceptance to improve dietary phytate
phosphorus (P) utilization and reduce the excretion of P in manure. Phytase was first detected
in rice bran many decades ago (Suzuki et al., 1907) and then Warden and Schaible (1962)
were rst to show that exogenous phytase enhances phytate-P utilisation and bone
mineralization in broiler chicks. First commercial phytase was produced from Aspergillus
niger and was released in market in 1991 (Selle and Ravindran, 2007). Phytases (myo-inositol
hexakisphosphate phospho-hydrolases) are a large family of hydrolases capable of catalyzing
the stepwise hydrolysis of myo-inositol hexakisdihydrogen phosphate (phytic acid; IP6).
Feed-relevant phytases are divided into 2 subclasses; the 3-phytases such as those from
Aspergillus niger initiate phytate degradation at the 3rd carbon position and 6-phytases such
as those from Peniophora lycii, Escherichia coli and Aspergillus oryzae initiate phytate
degradation from the 6th
carbon position.
According to our current knowledge, since first phytase introduced commercially, efficacy of
phytases depends on many factors including origin, pH optima, stability to heat and
endogenous proteases, particle size and number of enzyme, any factor altering gastric pH,
location of phytin within the seed and its chemical associations with other nutrients, Ca/P
ratio, and also endogenous phytase activity of ingredients used in the poultry diets. So, great
efforts have been made to discover more efficient phytase in each step of the development
through years. There are now many commercial phytases from different origin and production
technology that make serious contribution to poultry industry. However, efficacy and cost

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benefits of phytases differ significantly among commercial phytases, because different
phytase enzymes have various characterizes based on sources from which they are derived so
they don’t exert the same effect and activity in the digestive tract.
Research efforts in recent years have focused on the isolation and development of more
efficacious phytase which overcome the above challenges. A series of experiments have been
performed in broilers and layers by Çiftçi and Ceylan from Ankara University during last 2
years in which graded level of a novel microbial 6-phytase originated from Aspergillus oryzae
was compared with inorganic P sources (DCP) and was also tested to other competitors. In
broiler trials through 0-3 weeks graded level of the phytase including 500, 1000 and 2000
FYT/kg in the 1st experiment, and 500, 1000, 1500 and 2000 FYT/kg in 2nd experiment
were compared to the graded level of inorganic P sources over negative control diets with
0.28% available P(aP) based on corn and soybean meal. In the first experiment, the novel
phytase significantly improved the growth rate and feed conversion where the results of 1000
FYT/kg were found equal to 0.15 % additional aP from inorganic P. Excreted P via manure
for 2000 FYT/kg phytase was reduced to 0.6% from 1.05% (43% reduction from positive
control) and ileal P digestibility was increased by 55 and 26% (P<0.01) with 2000 FYT/kg
compared to negative and positive control, respectively. 500 FYT improved ileal P
digestibility by 32% (P<0.01) over negative control (0.28% aP) and equal to positive control
(0.43% aP). In the second experiment, this trend was also continued and novel phytase
supplementation resulted better growth (P<0.01) and feed conversion ratio (P<0.05) over the
negative control (0.28% aP) and equal to the positive control. Manure P content was again
significantly (P<0.01) reduced to 0.57% from 1.06% as positive control diet (0.28% aP)
compared to 1500 FYT supplemented group. Ileal P digestibility was significantly improved
to 61.8% from 50.3% by 1500 FYT compared to positive control. 500 FYT was found to be
similar P digestibility with positive control, however 1000 and 1500 FYT/kg phytase
supplementation had better P utilization over the positive control (P<0.01). In the third
experiment, supplementations of 500, 1000 and 1500 FYT/kg phytase from Aspergillus
oryzae were tested with un-supplemented negative control (0.28% aP) and positive control
(0.43% aP) diets and also compared with 3 other commercial 6 phytases (2 of them originated
from E.Coli, and one of them from Pichia pastoris). 500 FYT Phytase from Aspergillus
oryzae had significantly better growth performance than negative control and was equal to
positive control birds (P>0.05). 1000 and 1500 FYT/kg had additional improvements over
positive control (P<0.01) and improved growth performance significantly (P<0.01). The ileal
P digestibility results was interesting for tested phytases in which phytase from Aspergillus
oryzae, 1500 FYT had the highest with 63.0% digestibility and the 500 FYT had 56.65%
while the other three phytases at 500 FTU/kg had at least 6% lower P (P<0.01) digestibility
with 48.64, 50.05 and 48.20% for Pichia pastoris and two E.Coli phytases, respectively.
In the layer trail (Ceylan and Çiftçi, 2012 unpublished yet) with Super Nick white hens,
graded level of the novel 6 phytase (300, 450, 600 and 1000 FYT/kg) was tested against to P
deficient negative control (0.14% aP) and to 4 increased level of aP from DCP (0.19, 0.24,
0.29 and 0.34% aP) in corn, soy and sunflower meal based diets. P deficient negative control
diet caused significant reduction in overall performance parameters including livability.

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Phytase supplementation had increased the performance significantly to the peak level
(P<0.01) recommended by producer of Super Nick. There was no significant differences
(P>0.05) between inorganic P source and novel Phytase in egg mass, egg weight and feed
conversion ratio, but overall survival rate was significantly higher in the phytase
supplemented hens. Manure P content was significantly reduced and ileal P digestibility
increased (P<0.01) by phytase. According to this long term layer trial, the novel 6 phytase has
significant potential to improve performance and mineral status of the birds without using any
inorganic P sources and reduce manure P content. Besides, 300 FYT is found well enough to
keep the performance, but each increment in phytase activity still have response.
These series of experiments confirmed that the novel phytase have great potential to alleviate
the anti-nutritional properties of phytate molecule for poultry and additional phytase over 500
FYT/kg up to 2000 FYT/kg still continue to breakdown the phytate.
Additional improvements in growth performance over bone development in our researches
can be attributed to the complete breakdown of phytate and removing it’s anti nutritional
properties on other nutrients. Liu and Ru (2010) reported that microbial phytase could
improve amino acids utilization by decreasing their endogenous losses in the intestine of
broiler chickens. Aureli et al.,(2013) showed modified intestinal morphology with phytase,
by resulting in longer jejunal (P<0.001) and ileal villi and wider villi in the duodenum (+27%)
and jejunum (+25%) compared to NC. It seems that phytase supplementation does not only
help the hydrolysis of phytate-P but also have a significant modification on the intestinal tract,
even more so in the proximal parts, which could help increase absorption.
We can conclude that efficacy of commercially available phytases in same activity do not
give equal improvements in birds. Benefits and contribution of novel phytases is beyond
improvement P digestibility which can be explained by effective breakdown of phytate
molecule than previous phytase generation. It must be also considered that using this kind of
novel enzymes would cause significant changes in dietary strategies and establishments of
poultry nutrient requirements. We think that the poultry industry has now a very powerful tool
to feed animals and protect the environment.