Effects of zinc source and level on growth performance and carcass characteristics of finishing pigs

Henrique S Cemin; Corey B Carpenter; Jason C Woodworth; Mike D Tokach; Steve S Dritz; Joel M DeRouchey; Robert D Goodband; James L Usry

doi:10.1093/tas/txz071

Effects of zinc source and level on growth performance and carcass characteristics of finishing pigs

Transl Anim Sci. 2019 May 8;3(2):742-748. doi: 10.1093/tas/txz071. eCollection 2019 Mar.

Authors

Henrique S Cemin¹, Corey B Carpenter¹, Jason C Woodworth¹, Mike D Tokach¹, Steve S Dritz², Joel M DeRouchey¹, Robert D Goodband¹, James L Usry³

Affiliations

¹ Department of Animal Sciences and Industry, College of Agriculture, Kansas State University, Manhattan, KS.
² Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS.
³ Micronutrients, Indianapolis, IN.

Abstract

An experiment was conducted to determine the effects of added Zn source and level on growth performance and carcass characteristics of finishing pigs. A total of 1,980 pigs divided into 2 groups [group 1: 1,008 pigs, TR4 × (Fast Large White × PIC L02) and group 2: 972 pigs, PIC 337 × 1,050], initially 33.3 kg, were used in a 103- or 114-d growth trial in groups 1 and 2, respectively. Treatments were arranged in a 2 × 3 factorial with 2 sources of added Zn, Zn hydroxychloride (ZnHyd; IntelliBond Z, Micronutrients, Indianapolis, IN) or Zn sulfate (ZnSO₄), and 3 levels of added Zn (50, 100, or 150 mg/kg). Diets contained a vitamin-trace mineral premix without added Zn and provided 76 and 162 mg/kg Fe and Cu, respectively. All diets contained 750 FTU/kg phytase. There was a total of 14 replicates per treatment. Pens of pigs were weighed approximately every 2 wk to determine average daily gain (ADG), average daily feed intake, and gain-to-feed ratio. At the end of the experiment, pigs were transported to a packing plant to determine hot carcass weight (HCW), backfat depth, loin depth, and lean percentage. Overall, there was no evidence (P > 0.10) for interactive effects of added Zn source and level for growth performance and carcass characteristics. Pigs fed diets with increasing added Zn had a tendency (P = 0.093) for a quadratic response in ADG, with the greatest ADG observed at 100 mg/kg added Zn. There was a linear improvement (P = 0.010) in carcass yield and a quadratic response (P = 0.045) in HCW, with pigs fed 100 mg/kg added Zn having the highest HCW. Pigs fed diets with ZnHyd had improved (P = 0.017) carcass yield and a tendency (P = 0.058) for greater HCW compared with pigs fed ZnSO₄. In summary, under the commercial conditions of the study and with diets containing 750 FTU/kg phytase, there were relatively small improvements in ADG of growing-finishing pigs fed added Zn beyond 50 mg/kg. Providing higher levels of added Zn improved carcass characteristics. Zinc source did not influence growth performance, but ZnHyd improved carcass characteristics compared with ZnSO₄.

Keywords: grow-finish; mineral; performance; zinc.