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Title: Strategies and efficacy of phytase supplementation and its interaction with pharmaceutical zinc oxide in newly weaned pigs
Author: Mansbridge, Stephen C.
ISNI:       0000 0004 7656 1656
Awarding Body: Harper Adams University
Current Institution: Harper Adams University
Date of Award: 2017
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Feeding the World sustainably in the 21st century and beyond is perhaps one of the biggest challenges mankind has faced. Plant based pig feeds contain significant quantities of phosphorus, essential for animal health and performance, but which is locked-up in phytic acid and associated phytate salts (only around 30% digestible). Since the 1990's, phytase enzymes have been added to non-ruminant feeds to enhance phytate digestibility. Recent evidence suggests that feeding super doses of phytase increases growth performance beyond that attributable to phosphorus release alone. In the UK, therapeutic levels of ZnO are often prescribed to prevent and treat post-weaning diarrhoea in newly weaned pigs, though some evidence suggests zinc may reduce the phosphorus releasing efficacy of phytase. Improving the efficiency of pig production, reducing environmental pollution and maximising the use of non-renewable resources may help contribute to a sustainable and secure global food chain. The objective of this study was to evaluate the optimal strategy for using phytase in weaner pig diets, in conjunction with pharmaceutical ZnO. Four live pig experiments were conducted to quantify the growth response to increasing dietary phosphorus, identify 'extra phosphoric' effects associated with phytase super dosing and to evaluate this response in ZnO medicated feed. Resulting recommendations are to super dose phytase (2000-8000 FTU/kg) for two weeks post-weaning; reducing to 100 0 FTU/kg in the third week post - weaning to fa cilitate bone mineralisation. I n this study, seemingly healthy pigs fed pharmaceutical ZnO at high levels (3100 mg/kg feed) showed reduced growth performance, possibly due to interactions between zinc and phosphorus. Further research into reducing levels of pharmaceutical ZnO in feed and the use of ZnO nanoparticles could help overcome these risks. There may also be justification for a higher inclusion of dietary digestible phosphorus in ZnO medicated diets post-weaning, especially in low phosphorus diets.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available