H/L ratio as a measurement of stress in laying hens – methodology and reliability
Autor: | Sabine G. Gebhardt-Henrich, Helene Pendl, T. L. Lentfer, E. von Borell, Ernst K.F. Fröhlich |
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Rok vydání: | 2015 |
Předmět: |
education.field_of_study
Correlation coefficient Population Reproducibility of Results Antibodies Heterophile General Medicine Stress (mechanics) Leukocyte Count Animal science Stress Physiological Crossover experiment Reference values Animals Female Animal Science and Zoology Lymphocytes education Chickens Reliability (statistics) Food Science H l ratio Mathematics |
Zdroj: | British Poultry Science. 56:157-163 |
ISSN: | 1466-1799 0007-1668 |
Popis: | Measuring the ratio of heterophils and lymphocytes (H/L) in response to different stressors is a standard tool for assessing long-term stress in laying hens but detailed information on the reliability of measurements, measurement techniques and methods, and absolute cell counts is often lacking. Laying hens offered different sites of the nest boxes at different ages were compared in a two-treatment crossover experiment to provide detailed information on the procedure for measuring and the difficulties in the interpretation of H/L ratios in commercial conditions. H/L ratios were pen-specific and depended on the age and aviary system. There was no effect for the position of the nest. Heterophiles and lymphocytes were not correlated within individuals. Absolute cell counts differed in the number of heterophiles and lymphocytes and H/L ratios, whereas absolute leucocyte counts between individuals were similar. The reliability of the method using relative cell counts was good, yielding a correlation coefficient between double counts of r > 0.9. It was concluded that population-based reference values may not be sensitive enough to detect individual stress reactions and that the H/L ratio as an indicator of stress under commercial conditions may not be useful because of confounding factors and that other, non-invasive, measurements should be adopted. |
Databáze: | OpenAIRE |
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