A solid-phase reverse immunosorbent test (SPRIST) based on the addition of an excess of rubella virus hemagglutinin was evaluated for the demonstration of rubella-specific immunoglobulin M (IgM), and the results were compared with those of the density gradient centrifugation technique. In a retrospective study in which 157 sera were tested, the two techniques yielded identical results (55 IgM-p...

A line of White Leghorn chickens was selected for high group productivity and longevity resulting in improved survival and feather score as well as reduced cannibalism and flightiness. Improvements in survival might have also been due to improved immunity. The present study was designed to test the hypothesis that selection for high (HGPS) and low (LGPS) group productivity and survivability als...

The impact of globalization on the emergence and spread of pathogens is an important veterinary and public health issue. Staphylococcus aureus is a notorious human pathogen associated with serious nosocomial and community-acquired infections. In addition, S. aureus is a major cause of animal diseases including skeletal infections of poultry, which are a large economic burden on the global broil...

The heterophil to lymphocyte (HL) ratio in the peripheral blood is increasingly being recognized as a reliable indicator of stress in birds. In this study we examined whether HL ratio, as well as the proportion of heterophils and lymphocytes, varied systematically with sampling time, date, age, climate conditions or with measures of maternal investment in female tree swallows (Tachycineta bicol...

A corticosterone model was used to study the effects of chronic and repeated stress during the rearing phase on physiology, the onset of lay and performance of laying hens in the subsequent laying period. Two hundred and seventy Hy-line brown layer pullets were reared in environmentally controlled battery cages. At 7, 11, and 15 weeks of age birds were exposed for 1 week to the following treatm...

Haemoparasites prevalence in birds can vary among species, age and sex groups and ecological conditions. To comprehend the host–parasite assemblages, it is important to investigate physiological mechanisms underlying the interactions in wild bird species. Here, using blood smears we investigated how leukocyte profiles in reed warblers (Acrocephalus scirpaceus) and sedge warblers (Acrocephalus s...

The different leucocyte types are an important part of the immune system. Thus, they have been used in ecological studies to assess immune function and physiological stress in wild birds. It is generally assumed that increased stress and decreased condition are associated with an increase in the ratio of heterophils to lymphocytes, the H/L ratio. We studied leucocyte profiles in relation to bod...

Leucocytozoon simondi is an apicomplexan blood parasite of waterfowl that frequently causes significant mortality, and thus is expected to provoke a significant immune response in hosts. Using blood smears collected in consecutive weeks from 30 wild-stock mallard, Anas platyrhynchos, ducklings, we tested with repeated measures analyses for associations between leucocyte profiles and L. simondi ...

The objectives of this study were to compare the behaviors, postures, and heterophil-to-lymphocyte ratios (H:L) of laying hens housed in a cage system when offered a Ca premolt treatment and low-energy molt diets vs. a traditional feed withdrawal (FW) treatment during and after molt. A total of 144 Hy-Line W-36 hens (85 wk of age), housed 3 hens/cage (413 cm(2)/hen), were used. Hens were allott...