The effects of alternative feeding strategies without zinc oxide in nursery swine diets and high phytase supplementation on sow and litter performance

Abstract

Two experiments were conducted to determine the effect of crude protein level in diets containing coarse wheat bran with or without pharmacological levels of Zn (provided by zinc oxide: ZnO) on growth performance and fecal dry matter of swine (n = 360 or n = 650 pigs for experiment 1 and 2, respectively). A third experiment used 360 nursery pigs to evaluate the effects of insoluble fiber source and crude protein level on growth performance and fecal dry matter. Experiment 4 used 109 sows to evaluate the effect of increasing units of Ronozyme HiPhos phytase in lactation diets on sow and litter performance. In Exp. 1, pigs fed pharmacological levels of Zn had improved growth performance. However, increased performance was not observed for pigs fed high levels of Zn in Exp. 2. Reducing crude protein and subsequently SID Lys in diets with coarse wheat bran in an attempt to reduce the occurrence of post-weaning diarrhea did improve fecal dry matter but did not maintain or improve growth performance. Pigs fed diets supplemented with high levels of feed grade essential amino acids did not have improved growth. Improvements in feed efficiency were observed for pigs with the addition of non-essential amino acids to diets containing coarse wheat bran. In Exp. 3, reducing crude protein level resulted in decreased growth performance while fecal dry matter was increased on day 17. The source or inclusion of dietary insoluble fiber had no effect on growth performance, while the inclusion of cellulose as a fiber source improved fecal dry matter. For Exp. 4, increasing phytase from 0 to 3,000 FYT/kg increased feed intake in late lactation and overall intake tended to increase. Linear improvements in pig survivability were observed with increasing phytase. Overall litter gain and weaning weight was maximized for sows fed 1,000 FYT/kg.