An assessment of the effect on weaned piglet growth performance brought about by super dosing phytase on diets adequate in P

“Super dosing” involves the use of enough phytase to release as much P as possible, optimize the digestibility of other phytate-bound nutrients, restore the Ca/P balance, and improve growth performance. It is common practice to evaluate phytase on Ca adequate/ P deficient diets even though a marginal Ca excess in such diets could decrease the efficiency of phytate hydrolysis. However, there is paucity of information on phytase use in P- adequate diets. Therefore, the interactive effect on weaned piglet growth performance brought about by super dosing phytase in P adequate diets was investigated. 112 piglets were randomized into four treatments with 7 replicates and 4 piglets per cage. Diets included a positive control (PC) having Ca/P ratio of 0.8:0.5%. The PC diet was formulated to meet or exceed the NRC (2012) Ca: STTD P standards for piglets weighing 5-7 and 7-11 kg. The negative control (NC) had Ca: STTD P ratios of 0.6:0.5%. Phytase was super dosed at 2000 FTU/kg from a standard 1000FTU/kg. Body weight (BW), daily gain (ADG), daily feed intake (ADFI) and feed conversion ratios (FCR) were measured. Improved results were noted with the PC diet relative to the NC. Super dosing phytase improved the ADG and FCR (p < 0.1). The overall FCR was also improved (p < 0.1). The maintenance of the adequate required Ca/P ratio alongside phytase use at super dose levels could be beneficial for improved feed efficiency in piglet diets.

Keywords: growth performance, phytase, super dosing, weaned piglets.

Published in the Proceedings of 2021 Annual Congress of KSAST (Korean Society of Animal Science and Technology).