Keywords: laying hens, retention density, chronic stress, glucose, creatinine, enzyme activity


The results of the study of physiological changes in the body of hens due to changes in the group size of their based on the analysis of the parameters of serum clinical biochemistry are presented. To do this, in a modern complex for the eggs production formed 4 groups of hens, each of which was kept in a separate poultry house-analogue in area and equipment, equipped with 12-tier cage batteries, the size of the cages in which varied. The group size of hens in each cage of the 1st group was 93 birds, the 2nd – 52 birds, the 3rd – 17 birds and 4th – 9 birds. At the age of 52 weeks, 30 blood samples were taken from hens of each group and bio-chemical parameters and enzyme activity in its serum were determined. It was found that the decrease in the group size of hens for their content in the cage of multi-tiered batteries from 93 to 52 birds is accompanied only by an increase in lactate dehydrogenase activity by 14.4% within the physiological norm. With a decrease in the group size from 93 to 17 birds, there is an increase in glucose by 7.5% and phosphorus – by 89.2% within the physiological norm, a decrease in the calcium to phosphorus ratio by 30.0%, an in-crease in aspartate aminotransferase activity by 17.7%, alkaline phosphatase – by 94.4%, gamma-glutamyltransferase – by 17.8% and lactate dehydrogenase – by 27.9%. The decrease in the group size of hens from 93 to 9 birds is accompanied by the develop-ment of chronic stress, which was manifested by hyperglycemia with an increase in glucose by 61.3%, creatinine – by 7.8%, a de-crease in calcium and phosphorus by 76.5%, which is confirmed increasing the activity of alkaline phosphatase by 107.4%, as well as aspartate aminotransferase – by 25.1%, lactate dehydrogenase – by 59.6% and gamma-glutamyltransferase – by 25.7%. Thus, the main effects of chronic stress caused by keeping hens in small groups are reflected in the biochemical parameters of their se-rum, namely in the increase of glucose, creatinine, enzyme activity, as well as the violation of calcium to phosphorus ratio.


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How to Cite
Osadcha, Y. V. (2022). SERUM BIOCHEMICAL PROFILE AND ENZYMES ACTIVITY OF HENS UNDER THE INFLUENCE OF GROUP SIZE. Bulletin of Sumy National Agrarian University. The Series: Livestock, (4 (47), 114-118.