Including copper sulphate or dicopper oxide in the diet of broiler chickens affects performance and copper content in the liver

Copper supplementation (125–250 ppm) in poultry diets is a common practice in many non-EU countries to enhance bird health, but high amounts of Cu may interact with phytate and affect animal performance. The effects could depend on the nature of the Cu source. Thus, the objective of this trial was to compare the effects of two sources of Cu, copper sulphate (CuSO4) and dicopper oxide (Cu2O, CoRouge®), at three levels of dietary Cu (15, 150, 300 ppm). A total of 576 one-day-old male broiler (Ross 308) were distributed into 6 experimental groups (8 pens/treatment, with 12 birds/pen). Body weight (BW) was individually monitored and feed disappearance was determined at 14, 28 and 35 d of age. On d 35 post-hatch, one bird per replicate was euthanized, the skin fat and breast muscle were sampled, and the liver and kidneys were collected. The two Cu sources were also evaluated in vitro to measure Cu and phytic phosphorus (PP) solubility, and PP hydrolysis by phytase at pH 2.5, 4.5 and 6.5. The use of 300 ppm of CuSO4 decreased (P = 0.001) BW on d 14, 28 and 35 and increased (P = 0.04) liver Cu content in comparison with the use of 300 ppm of Cu2O. The feed-conversion ratio increased for broilers of the 300 ppm CuSO4 group in comparison to the 300 ppm Cu2O group (2.19 vs. 1.84, P < 0.001). The use of the highest level of Cu (300 ppm), either of Cu2O or CuSO4, also increased (P < 0.001) Cu concentration in kidney and breast muscle in comparison to 15 and 150 ppm. In the in vitro trial, including a level of 300 ppm reduced PP solubility with CuSO4 (68.66%) in comparison to Cu2O (97.41%), and reduced PP hydrolysis by phytase at pH 4.5 and 6.5 with both sources. It can be concluded that dietary levels of 150 and 300 ppm Cu of Cu2O are adequate to ensure broiler growth performance and limit organ accumulation in comparison to CuSO4.