Cu influence on hens egg productivity

Abstract
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 10th to 22nd 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 9th ... 12th 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.