Changes in the cortisol and some biochemical patterns of pregnant and barren jennies (Equus asinus)

Changes in cortisol and some biochemical values are likely to occur during pregnancy in different species, although homeostatic mechanisms function to keep substrates in the blood at comparatively constant concentrations. There are no complete data for this important endocrine and metabolic status in jennies. Since metabolic functions are increased during pregnancy to satisfy the demands of the foetus, the placenta and the uterus, the purpose of the present study was to determine which physiological changes occur in plasma cortisol and total protein, creatinine, urea, metabolism in pregnant jennies and hence to compare these fi ndings with those of barren jennies. The study was carried out in 24 healthy Ragusano jennies (10 pregnant and 14 barren). Blood samples were collected monthly from the jugular vein of pregnant and barren jennies in one year. As compared to barren jennies, pregnant jennies showed lower cortisol(P<0.05) and urea (P<0.05) values and higher creatinine (P<0.01) values. Total protein values and AST and ALT activities showed a similar pattern both in pregnant and in barren jennies, and did not differ signifi cantly. The existence of signifi cant differences in cortisol, creatinine and urea concentrations between pregnant and barren jennies showed the relevant involvement of the physiological state on the endocrine and biochemical homeostasis. These fi ndings were confi rmed by positive and signifi cant correlations between cortisol and biochemical parameters.