Abstract
An 84-d feeding experiment was conducted to evaluate the growth performance, bone quality indices and trace mineral bioavailability in growing turkeys fed diets containing varying levels of supplemental inorganic and chelated blend of Cu, Zn and Mn. A total of three hundred and twenty 28-d old British United Turkeys (BUT) initial meat weight of birds (1200 plus or minus 10 g) were assigned to 8 dietary treatments in a 2 × 4 factorial arrangement of diets containing Chelated trace mineral blend (CTMB) and inorganic trace mineral blend (ITMB), supplemented at 4 levels; zero (0.00 mg/kg Cu, Zn and Mn); low (0.60 mg/kg Cu, 2.56 mg/kg Zn, 2.08 mg/kg Mn); optimum (1.20 mg/kg Cu, 5.12 mg/kg Zn, 4.16 mg/kg Mn) and high (6.00 mg/kg Cu, 25.60 mg/kg Zn, 20.80 mg/kg Mn). Each treatment was replicated four times with 10 turkeys per replicate. The turkeys were housed in an open-sided, deep litter system which was partitioned using wire mesh into 32 pens with each pen (of dimension 2 m × 3.5 m) representing a replicate. Final live weight and weight gain of birds fed CTMB over those fed ITMB supplemented diets were not significant (P >0.05). However, supplementation with CTMB led to an improved (P <0.05) feed conversion ratio in turkey poults. Dietary supplementation with increasing levels of CTMB led to an improved (P <0.05) bone breaking strength over those of the control. Concentration of Cu and Mn in the serum and Cu and Zn in the liver was higher in turkeys fed CTMB supplemented diets compared to values obtained in those fed ITMB supplemented diets. It was concluded that Cu, Zn and Mn from mineral chelates were more bioavailable compared to those from inorganic salts.
