Phosphorus is one of the essential minerals for all the living organisms including poultry. Phosphorus being a part of energy currency, plays a critical role in cellular metabolism as well as also required in bone formation. Phosphorus is bound to phytic acid in plants thus doesn't get avail to poultry. To compensate this, additionally, Phosphorus source supplements such as dicalcium phosphate are added in the feed. This addition increases the feed cost and decreases the profitability out of poultry production. In addition to this, the bound phosphorus is excreted as it is in the environment, thus polluting the environment also (Peter.H.Selle et al). Apart from decreasing phosphorus availability, phytic acid chelates with various divalent, amino acid and decreases their absorption as well. To overcome aforesaid problems, Phytase development and addition has been a very innovative approach to bring the best out of nutrition and to reduce the cost of production. Phytase catalyses the hydrolysis of phytate (present in feed) in stepwise manner and releases bound phosphorus and inositol, thus reducing the cost of additional phosphorus in diet. Solely the addition of phytase wouldn't reduce the cost or would increase the efficiency of production. Various attributes that are associated with the stability of enzymes should also be considered to meet out the actual benefit out of the addition of phytase enzyme. In this article stability parameters linked with phytase and their importance is discussed.
NEED OF PHYTASE ADDITION
- Augmenting phosphorus release
Exogenous phytase, when added in the feed, releases the bound phosphorus in stepwise manner and thus increases its availability to the bird.
To compensate the deficiency of phosphorus, additional phosphorus is added in the diet in the form of dicalcium phosphate that results in increase feed cost. Phytase addition somewhere reduces the feed cost by increasing the availability of phosphorus and decreasing the requirement of addition of phosphorus source in the feed.
- Diminishing the environment pollution
Phosphorus being in bound form, passes in the excreta as such, thus being deposited in the natural resources. Extraction of phosphorus leads to depletion of non-renewable resources. Phytase addition solved this problem to some extent.
ATTRIBUTES ASSOCIATED WITH THE ADDITION OF EXOGENOUS PHYTASE
In general, enzyme being a biocatalyst should be stable to show its complete activity and to fulfill the purpose it is specifically manufactured for.
- Ideal feature of Phytase when in operation
o Thermostability- to withstand high pelleting temperature.
o Good gastric tolerance and stability to resist birds' own enzymes.
o Stability at low pH.
o High rate and extent of phytate breakdown- to sustain its activity even at low phytate concentration.
- Storage stability of phytase- storage ae room temperature (73°F) or 39 to 73°F at low humidity is ideal to optimize phytase stability and maximize phytase activity during storage (Sulabo et al., 2011; De Jong et al., 2016).
- Structural aspect of phytase- At present there are 4 classes of phytase that are believed to hydrolyse phytate.
PELLETING TEMPERATURE AFFECTING THE EXOGENOUS PHYTASE
Broiler ration are typically pelleted to promote improved broiler performance but high pelleting temperature can inactivate the conventional phytase enzyme. Feed pelleting process involves temperature around and even in excess of 80°C, under this condition the common phytase enzyme gets denatured and loses enzymatic activity. Limitation to most commercially available phytase is that they are inactivated when pelleted above 75°C-80°C. Moreover, lower than the desired activity of added phytase in feed can have a visible negative impact on lameness (weak bones and egg shell) in poultry. Therefore it becomes imperative to provide special attention to heat stability of phytase.
METHODS TO INCREASE THERMOSTABILITY OF ENZYME
Phytase with improved thermostability would meet the purpose of inclusion of this enzyme in poultry diet. For a phytase additive to be optimized, it must also be thermally stable.
Figure: Several strategies that have been proposed to improve stability of enzymes
POTENTIATED PHYTASE BASED ON IMMOBILISATION TECHNIQUE
In order to increase the potential benefit of phytase in poultry diet, it becomes mandatory to increase the heat stability of phytase. Potentiated phytase is that phytase where its activity is potentiated by a special technology which shall provide protection against high temperature that occur during pelleting and conditioning. Moreover, this technology impairs the enzyme movement in space. Immobilization of enzyme is one of the techniques which enhances the stability of the enzyme.
Highly thermostable phytase OZYME P ADVANCE being a potentiated phytase stands out to be an indispensable product which is based on a special technology that is thermo-protection technology.
Using this technique enzyme movement has been restricted either completely or to a small limited region.
This results in:
Multiple trials were performed in vitro to test the efficacy of potentiated phytase and assess its activity. These trials justified that Ozyme P advance, being a highly thermostable phytase, was able to retain its activity even at high pelleting temperature and fulfilling the requirement of addition of phytase in feed. With increase in choice of phytase products, there is a need for feed producers to compare and optimize phytase addition for maximum economical benefit. Thermostability proves to be a reliable parameter for the optimization of phytase use in feed.
The poultry sector, being one of the developed sectors, is moving towards continuous change. To bloom the sector it is necessary to bring the nutritional parameter also in track. Discovery of exogenous enzymes was a boon to the grooming industry. Economic justification for producers to use phytase is clear, now it’s important for feed manufacturers is proven enzyme heat and storage stability. It is imperative to add phytase in the feed. Addition of thermostable phytase would bring the best out of the discovery of that enzyme. Therefore the profitability out of addition of exogenous enzyme now relies on selection of phytase which is thermostable.