Correlation Between Blood Parameters, Physiological and Liver Gene Expression Levels in Native Laying Hens Under Heat Stress

Abstract

The heat stress plays an important role in feed efficiency, blood profile, rate metabolism. Growth performance, health and its influence economic loss of layin hens can be strongly affected by climate. The study to investigate the effect of the heat stress on blood parameters (White Blood Cells/WBC, lymphocytes, neutrofils, glucose, creatinine, creatinine kinase/CK), physiological status (rectal temperature/RT, heart rate/HR), and liver gene expression (Glutamate pyruvate transaminase/GPT, Glutamate oxaloacetate transaminase/GOT, Threonine dehydrogenase/TDH, heat shock protein 70/HSP70) in laying hens. Two hundred native laying hens were randomly assigned to 10 groups of temperature humidity Index (THI), with 20 animals per group. They were kept in environmental condition with temperature humidity index (THI) ranging from 65.50 to 85.72 in temperature humidity. Blood plasma samples were used to determine the concentration of blood biochemical parameters, using a commercial kit by an automatic biochemical analyser. Liver gene expression levels were analyzed by Real-time PCR. The results showed that their RT, HR, WBC, neutrophilis, creatinine, CK, liver gene expression levels were increased in high THI compared to at low THI. In contrast, glucose and lymphocytes levels was decreased in high THI. In addition, HR, RT, WBC, neutrophilis, creatinine, CK, liver gene expression were positively correlated with THI. On the other hand, negatively correlated with THI were showed by glucose and lymphocite. As conclusion, based on these results, it can be concluded that all parameters in this study are closely associated with heat stress. These parameters can be consolidated to heat stress biomarkers in native laying hens.