The effect of dietary supplementation of organic trace minerals on performance, mineral retention, lymphoid organs and antibody titres of broilers

Abstract

Complete replacement of inorganic trace minerals (ITM) with proteinated organic trace minerals (PTM) at equal or lower inclusion rates was evaluated. One thousand and eight, one-d-old male chicks were divided into 24 pens containing 42 chicks, and randomly allocated to one of the following: T1: control group with ITM supplied at the standard commercial level in Ecuador; T2: PTM at 100% T1; T3: PTM at 66% TI; and T4: PTM at 33% T1. The 42-d experiment employed a three-phase feeding programme (1-14, 15-28 and 29-42 d). Restricted feeding was used to prevent the development of ascites associated with high altitude. At 21 and 42 d of age, Cu, Mn and Zn retention were measured in tibial bone, and Fe in whole blood. Lymphoid organ weights were at 21 and 42 d of age. Antibody titres were measured by ELISA at 42 d of age. Weight gain, feed consumption, feed conversion and mortality were similar among treatments, although were below breed expectations due to feed restriction practices. Blood Fe was not affected by treatment (P<0.05). At both 21 and 42 d of age, minerals in tibia differed (P<0.01), with Mn and Zn concentrations being significantly higher in all PTM groups, compared to ITM control at 42 d. However, at 21 d, Zn was higher for the ITM-fed birds. No differences in lymphoid organ (bursa, thymus, and spleen) weights were observed, or for Gumboro (infectious bursal disease), infections bronchitis virus and reovirus antibody titres. For Newcastle disease virus, T4 birds had significantly lower antibody titres compared to other treatment groups. In conclusion, replacement of inorganic minerals with a proteinated form organic minerals at lower inclusion rates had no negative impact on performance, lymphoid organ weight or antibody titres in broilers raised under commercial conditions of high altitude and restricted feeding.