The effects of supplemental levels of inorganic zinc, manganese and copper on growth performance in commercial broilers.

ABSTRACT

Commercial broiler premixes provide trace minerals (TMs) such as Zinc (Zn), Manganese (Mn) and Copper (Cu) above the birds' requirements to maximise broiler performance. High inclusion levels of TM and their low absorption in the broiler's gastrointestinal tract have led to increased TM levels in their litter, raising concerns about TM's accumulation in the environment from poultry litter. A 35-day broiler trial was conducted at a broiler facility with 2 880-day-old Cobb 500 broiler males. The objective was to evaluate whether decreasing inorganic Zn, Mn and Cu levels in broiler diets would have a negative effect on broiler growth parameters such as BW, average daily gain, cumulative feed intake (FI) and feed conversion ratio (FCR). Consequently, these minerals were supplemented at 100%, 50%, 25%, and 0% of the Cobb standards. No significant difference in FI and FCR was observed between the treatments for the first 21 days, and there were no significant differences in BW between the positive control, negative control (NC), and 50% of Cobb recommended levels at day 35. However, BW for the NC was significantly higher than the 25% level. These results show that reducing TM levels in broiler diets below commercially recommended levels had no negative effect on broiler performance, with the subsequent economic benefits for producers.