Effect of supplemental zinc source and corn particle size on 40-day broiler performance

Zinc (Zn) supplementation source and particle size of feed ingredients are two factors that can affect poultry performance and should be considered for proper feeding of poultry. The objective of the current study was to assess the effects of Zn supplementation source and corn particle size on broiler performance, breast yield, and tibia Zn concentration. Treatments were arranged in a 5 x 2 factorial randomized complete block design with the main effects Zn treatment and corn particle size (550 micron vs. 1,050 micron). Zinc treatments included a basal diet (no added Zn), 80 mg/kg Zn sulfate, and 3 diets with 40 mg/kg Zn sulfate + 40 mg/kg of either Zn-glycine amino acid (AA) chelate (Zn-gly), Zn-AA complex (Zn-AA), or Zn bis(-2-hydroxy-4-methylthio) butanoic acid (Zn-HMTBA). A total of 8 replications per treatment were fed to 23 broilers per pen from d one to 40. A Zn treatment x corn particle size interaction was observed for ending bird weight (EBW; P < 0.05) demonstrating that feeding small particle corn produced larger broilers except when supplemental Zn was not included. Broilers fed small particle corn or diets supplemented with Zn consumed the most feed (P < 0.05); however, FCR was decreased (P < 0.05) by 1.9 points for broilers fed large particle corn diets. Tibia Zn concentration was higher (P < 0.0001) for Zn supplemented diets, but no other treatment effects were observed. In conclusion, Zn supplement source had little effect on broiler performance; however, Zn supplementation per se optimized performance.