Abstract
The chemical fitness of water used in some broiler farms in Behera and Kafr El sheikh Provinces was assessed and effects of some of the detected chemical pollutants on the body weight and the immune response of broiler chicken to some vaccines including New castle disease (ND) and infectious bursal disease (IBD) vaccines were studied. A total of 100 water samples were collected including; 71 water samples from chicken farms (44 samples from underground water and 27 from tap water) and 29 water samples were collected from streams and canals located at the same areas of chicken farms. Chemical examination was performed at The Central Laboratory, Faculty of Agriculture, Kafr El Sheikh University to determine the levels of lead, iron, copper, zinc, manganese, cadmium and cobalt. The obtained results revealed detection of lead, copper, iron, zinc, manganese in some of the examined sample and their maximum concentration were 0.23, 0.67, 2.15, 7.75, 2.99 mg/l, respectively while cadmium and cobalt could not be detected in all samples. The effects of the detected chemical pollutants on the body weight and the immune response of broiler chicken to some vaccines were evaluated. 195 one day old broiler chicks were randomly selected and divided in to 6 groups (each group contains two sub groups; each sub group contains 15 chicks), that were received water with selected chemical pollutants including lead, iron, copper, zinc and manganese and one group containing 15 chicks was reared as a control group that received distilled water. All the experimental groups was vaccinated against ND and IBD then the antibody titers of ND and IBD vaccines was measured by the Heamagglutination Inhibition Test (HI test) and Enzyme linked Immunosorbent Assay (ELISA), respectively. The obtained results revealed that the group of chicks received water containing the low and high levels of lead showed a significant decrease in antibody titer when compared with control group. Also, the group received treated water with high level of copper showed a significant decrease in the antibody titer of ND at days 21 and 28 when compared with control group. Results of ELISA showed a significant decrease in antibody titer of IBD at day 21 in the group received water containing the high dose of copper. By comparing the final body weight of all groups, it was observed that there was a significant decrease in the body weight of groups received high level of lead and high level of all pollutants together. On the other hand, there was a significant increase in the body weight of the group received high level of zinc. Finally, it was concluded that lead and copper had an adverse effect on the immune response of broiler chicken and their body weight so periodical examination of water for presence of chemical pollutant especially heavy metals is suggested.

Key words: Heavy metals, Broiler chicken, Immune response