Nutrition

News 326 views last update:6 Aug 2012

Thermostable enzyme helps meet demands for safer feed

A new xylanase enzyme, developed by Danisco, has recently been authorised by the EU commission for use in poultry diets.

This xylanase, from a fungal production system (Trichoderma reesei), has been modified to maintain high efficacy despite exposure to feed conditioning and pelleting temperatures of up to 90ºC.
 
The use of a heat-stable xylanase can reduce the negative effects of increased viscosity in poultry diets pelleted at 90ºC.
 
Trials have also shown that increasing the pellet conditioning temperature for poultry diets from 80ºC to 90ºC in ‘viscous’ grain-based diets resulted in a significant decrease in body weight gain by up to 7% and gave a poorer feed conversion ratio (4.4%) in broilers.
 
Xylanases improves feed efficiency
Addition of xylanase increases the energy value of wheat-based diets. It is therefore particularly important when formulating diets using viscous grains such as wheat, triticale and rye that an exogenous xylanase is used to minimise the negative impact of viscosity on bird performance.
 
However, any exogenous xylanase has to be stable enough under higher pelleting temperatures to maintain its activity and efficacy in the animal.
 
Protect or modify
This can be done by coating to protect the enzyme or manipulate the enzymes to make them more heat resistant.
 
Danisco has used a patented Thermo Protection Technology (TPT) to design a free-flowing, dust-free phytase granulate product (Phyzyme® XP TPT) with a recovery rate of 96% after exposure to feed pelleting temperatures of up to 95ºC.
 
Trials have proven a fast release of phytase activity from this coated product and bioefficacy equivalent to the uncoated product in mash diets.
 
The second technology, modifying an enzyme by changing its amino acid structure to improve thermostability, has been widely tested in recent years.
 
This technique includes the substitution of surface amino acids in the enzyme with more hydrophobic amino acids, as well as an increase in the number of specific amino acids which are capable of forming cross-bonds within the enzyme molecule.
 
It is this approach that Danisco has chosen for the development of the new xylanase.
 
The full article with more detail can be read here.
 

Dick Ziggers

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