Phytase Superdosing Unlocks Zinc Potential to Improve Swine Performance08 July 2016
Young pigs raised under commercial conditions typically don’t eat enough to grow to their full potential during the first few weeks post- weaning for a variety of reasons including immunological challenges and environmental stress. This often leads to significant issues around mortality and welfare.
Mineral nutrition is an important factor in reducing piglet health challenges and improving overall performance. Piglet diets tend to be more expensive than diets for the grower/finisher pigs so it is critical ingredients are included to maximize the efficiency of the feed and to give piglets the best start.
Scouring in post-weaning piglets causes significant financial losses as a result of mortality, morbidity, decreased growth rate and cost of medication. Zinc oxide is a well-established mineral salt that reduces symptoms of scouring and enhances performance. Starter feeds typically contain pharmacological levels of zinc (>25000 ppm) added as zinc oxide.
However, phytate, the storage form of phosphorus, binds minerals, including Zn, rendering them unavailable for absorption by the animal. Undigested minerals are excreted in the soil causing contamination of water-streams and soil and are considered an environmental pollutant and a health hazard.
Destroying phytate with phytase superdosing improves zinc absorption
Phytase superdosing involves the use of a highly efficient phytase to target near complete phytate destruction. It is important to break down phytate (IP6) and its lower esters such as IP4 and IP3 as quickly as possible, for maximum mineral absorption and performance benefits. Five trials conducted with Quantum Blue phytase, dosed at 2500 FTU/ kg immediately post-weaning up to 21 days, demonstrated the impact of phytase and Zn on piglet performance.
The addition of superdosed phytase improved performance at all levels of Zn tested by 10-30% with the highest ADG at 30% obtained at medium levels of Zn with superdoses of Quantum Blue, suggesting that even when Zn was reduced from high to medium supplementation, growth rate was improved beyond that of the high Zn diet alone.
This shows that the level of pharmacological Zn may be reduced by 500-750 ppm in the presence of superdosing phytase without affecting performance. In comparison to a non-phytase diet, superdosing phytase at 2500 FTU/kg in post-weaned pigs resulted in increased serum Zn, indicating an improvement of Zn utilisation which may in part explain the growth performance benefit as well as the reduction in post-wean scour.
For the anti-nutrient effects of phytate to be eliminated, 80-85% of total phytate typically needs to be degraded – beyond just IP6. Understanding the relationship between phytate, phytase and Zn is important in optimising the post-weaning performance of pigs with phytase superdosing and pharmacological Zn levels. Lower levels of pharmacological Zn may be an option in the future to maximise post-weaning performance using phytase superdoses.
OPTIMAL PHYTASE CHARACTERISTICS:
- Intrinsic thermostability
- Efficacy early in the gastrointestinal tract at low pH
- High activity at low substrate concentrations