Cu influence on hens egg productivity

The high Cu content was detected in water, soil and plants of some areas in East Siberia region [1]. That is why it is necessary to study the influence of Cu on animals' productivity and morbidity. 5 group of cross Rodonit hens were taken for an experiment. For 30 days the hens from experimental groups (2 - 5) were drunk with water where Cu content was 5, 10, 20 and 30 times higher than the upper limits (UL). In group 1 (control) the egg laying was 0.63 and in group 2 (5 UL) - 0.70. Hens of group 3 (10 UL) decreased the egg productivity for 6 days followed by their 3 - day cease to lay egg. From the 10 th to 22 nd day of the experiment the egg productivity restoring was marked (to 0.55). Besides 20% of the hens died for the last 10 days. In group 4 (20 UL) the dramatic decrease in the egg laying was revealed at the very onset and the productivity breaking off from the 9 th ... 12 th day of the study. 70% of the hens died during the first 13... 17 days. In group 5 (30 UL) the egg productivity was 5 times less than in the control for the first decade and all the hens died for 2... 14 days. Thus, Cu is toxic in concentrations more than 10 UL and may cause the decrease of the egg productivity and even death of hens.