Response of feeding different sources and concentrations of zinc and copper on performance of broiler chickens

An experiment was undertaken to evaluate the response of broiler chicken to supplementary sources and concentrations of zinc and copper with reference to the growth, immune response and carcass traits. A six weeks (0–6 weeks) feeding trial was conducted involving two Zn levels (40 and 80 mg/kg) each with two Cu levels (8 and 16mg/kg) and again each with two mineral sources (organic and inorganic) in the form of Zn propionate and Cu propionate (organic) and Zn sulphate and Cu sulphate (inorganic) through a 2 x 2 x 2 factorial experiment. Each of such test diet was offered as mash ad lib to four replicated groups of 8 chicks each. Significantly (P<0.001) higher body weight gain (BWG) and feed conversion ratio (FCR) of chicks was observed at 16 mg Cu/kg than that recorded at 8 mg Cu/kg diet during different growth phases. There was no significant effect on BWG due to Zn levels and mineral sources. The feed intake did not differ significantly due to different levels of Zn and mineral sources. However, it was significantly (P<0.05) higher at 16 mg Cu/kg than 8 mg Cu/kg diet during 4–6 wks of age. No significant effect was observed on FCR due to Zn levels, mineral sources and interaction among Zn, Cu and mineral sources. The HA titer to SRBC and foot pad index to PHAP was significantly (P<0.01) higher at both higher levels of Zn and Cu with organic sources as compared to their lower levels with inorganic sources of minerals. The various carcass quality traits were not affected by different treatments. However, the relative organ weight (liver and heart) were significantly higher at lower level of Zn and higher level of Cu. Based on the results it may be concluded that a dietary combination of 40 mg zinc and 16 mg copper/kg diet either organic or inorganic form of mineral was found adequate to obtain optimum growth performance and carcass yield. However, better immune response can be realized with a dietary combination of 80 mg zinc and 16 mg copper/kg diet with organic source.