There is a growing interest concerning the welfare problems associated with harvesting, transportation and pre-slaughter handling of broilers. Transportation is a multifactor process associated with a variety of stressors which may covertly reduce welfare. Plasma corticosterone is elevated following a road which is consistent with the post-transport increase of heterophil: lymphocyte ratios (H/...

BACKGROUND Blood parameters such as haematocrit or leucocyte counts are indicators of immune status and health, which can be affected, in a complex way, by exogenous as well as endogenous factors. Additionally, social context is known to be among the most potent stressors in group living individuals, therefore potentially influencing haematological parameters. However, with few exceptions, this...

Three trials were conducted to assess the effects of stocking density on physiological adaptive responses of broilers. Male broilers were reared in floor pens under conditions similar to those used commercially in the United States. Accepted indicators of adaptation to a stressor were measured on d 49 including plasma concentrations of corticosterone, glucose, cholesterol, and total nitrites as...

The heterophil to lymphocyte ratio has become widely accepted as a reliable and accurate physiological indicator of the stress response in chickens (Gross and Siegel, 1983), because exposure to stressors causes it to increase progressively. Gross and Siegel (1993) suggested that reference values for the heterophil to lymphocyte ratio of about 0.2, 0.5 and 0.8 are characteristic of low, optimal ...

Heterophil phagocytosis of fluorescein-labeled staphylococcal bacteria was analyzed by flow cytometry. Opsonization with two types of normal pooled sera and staphylococcal antisera significantly increased bacterial phagocytosis compared to samples without an opsonin. The staphylococcal antisera did not significantly increase bacterial phagocytosis compared to the normal pooled sera. Opsonizatio...

The zebrafish (Danio rerio) has emerged as an informative vertebrate model for developmental studies, particularly those employing genetic approaches such as mutagenesis and screening. Zebrafish myelopoiesis has recently been characterized, paving the way for the experimental strengths of this model organism to contribute to an improved understanding of the genetic regulation of myeloid develop...