ASSESaSMENT OF HEAVY METALS IN CHICKEN FEEDS OBTAINED FROM UYO. AKWA IBOM STATE, NIGERIA.

Abstract

Assessment of heavy metals was carried out to determine the concentrations of copper, cadmium, nickel and lead in chicken feeds obtained from Uyo metropolis, Akwa Ibom State, Nigeria. Three feed types (starter, layer and finisher) of three commercially available brands (X, Y and Z) were purchased from markets in the city. The samples were prepared for analysis by wet digestion method and heavy metals analysis was carried out using an Atomic Absorption Spectrophotometer. The mean concentration of heavy metals (mg/kg) were in dry weight; the levels of copper varied from 5.69 to 26.79 mg/kg and were found to be present in the sequence; Finisher > Starter > Layer. The observed mean values of Cd ranged between 0.18 to 1.47 mg/kg and the levels of Cd in the different brand of feed increase with the trend, Z > Y > X. The mean concentration of nickel ranged from 0.80 - 4.78 mg/kg and the contamination sequence of nickel for the different feeds were Starter> Layer > Finisher, while the levels of lead in the different brands of feed were in the range of 0.00 - 2.4 mg/kg. The observed levels of copper and lead were low in the feed while amongst all the different brands studied, Cd mean values of 1.02 ± 0.73 for Z was slightly above the recommended limit of 1.0 mg/kg. Furthermore, Nickel concentrations were slightly higher in the feed samples analyzed, when compared with the recommended limits. Statistically, it is observed that the Fcrit > Fcal (3.44 > 0.41) for the types of feed, therefore there is no statistically significant difference between the types of feed evidence at α = 0.05, as confirmed by a P value of 0.67. t- test analysis showed that, there was no significant difference in Cd between Y and Z brands as the observed P0.05 was for two samples assuming equal variances were 0.41 and 0.82 for one tail and two tail respectively and the observed P value for two samples assuming unequal variances were 0.42 and 0.84 for one tail and two tail respectively. The heavy metals load in the different types of feeds was found to be at non-toxic concentrations, except for cadmium and nickel. These metal contaminations may arise from environmental factors, production line processes, poor handling and storage by the retailers. The deficiency or the elevation of these heavy metals affects the normal physiological activity and biochemical process of the chicken which in turn affect the health of humans.