Improved Broiler performance by Trace Minerals

Trace minerals are important for broiler growth and are used in various physiological, digestive and biosynthetic process of the body. Trace minerals act as cofactors in many enzymes and are associated with proteins involved in intermediary metabolism, hormone secretion path ways and the immune system (Dieck et al., 2003). In broilers, organic trace minerals are better absorbed and utilized and have a greater bioavailability than inorganic trace minerals (Bao et al., 2007). This experiment was conducted to examine the effect of trace mineral sources on broiler performance and carcass composition. Four hundred eight Ross 308 male d-old chicks were allocated to 24 pens and assigned to 4 dietary treatments with 6 replicate pens of 17 birds per treatment. Treatments were: inorganic trace mineral premix (IM) 750 g/t, organic yeast proteinate trace mineral premix (YP) 375 g/t, YP 500 g/t and salt encrusted trace mineral premix (SE) 1000 g/t. Between 1 and 21 d, no differences in feed intake (FI), body weight gain (BWG), feed conversion ratio (FCR) or livability (LIV) were observed between treatments (P > 0.05). Between 1 and 38 d, however, YP (375 g/t) and SE improved weight gain (P < 0.05) and large improvements in FCR (P < 0.001) were observed relative to the IM treatment. This is despite the fact that the IM was more concentrated in mineral content than other treatments. The IM diet had 3.3 ×, 3.2 ×, 2.7 × and 4 × the levels of added Zn, Cu, Fe and Mn respectively compared to YP 500. Treatment had no impact on FI or LIV (P > 0.05). Spleen percentage of body weight at 25 d were increased in the YP (375 g/t) and SE treatments (P < 0.05) over the IM treatment possibly reflecting improved immune status of the birds or higher iron digestion. Mineral source had no effect on thymus weight and bursa of Fabricius weight at 25 d or dressing percentage at 39 d (P > 0.05).

Table 1 - Growth performance and carcass attributes of broiler chickens fed various mineral sources