G. Asdrubali

Development of a Polymerase Chain Reaction-Based In Vivo Method in the Diagnosis of Subclinical Pigeon Circovirus Infection

Abstract This paper describes a polymerase chain reaction (PCR)-based method performed on blood samples and intestinal content to detect subclinical pigeon circovirus (PiCV) infection in live pigeons. In addition, two sets of primers (primer set 1 and 2), designed in two different regions of the viral genome, were used to provide evidence of possible differences in PCR responses. Blood and intestinal content samples were randomly collected from a total of 50 apparently healthy meat pigeons, aged 1 to 5 wk, which came from central Italy. Samples of primary lymphoid organs were also collected. Results showed a high level of PiCV infection, although clinical signs were not present. The results obtained with the two sets of primers showed that primer set 2 was able to detect a higher number of PCR-positive pigeons (45 of 50 pigeons) than primer set 1 (11 of 50 pigeons). In both cases an increase in positive results with pigeon age indicates that the major direction of transmission is likely horizontal. In these circumstances feces can play an important epidemiologic role, as supported by the consistent circovirus detection in intestinal content. The high sensitivity of this PCR test, which is able to detect very low amounts of viral DNA (5.5 × 10−3 fg of plasmid containing the cloned PiCV genome), makes it suitable for possible application as an epidemiologic tool for identifying virus carriers for subsequent removal from lofts.

Isolation and characterization of an adenovirus associated with inclusion body hepatitis in psittacine birds

An outbreak is reported of inclusion body hepatitis in psittacines from a private aviary, in which several birds aged between 35 and 75 days had died without showing any clinical signs. Histological examination of the livers revealed severe hepatic damage with presence of large basophilic intranuclear inclusion bodies. Avian adenoviruses were isolated from the affected livers. Characterization of the isolates by means of restriction endonuclease analysis showed that they were similar to reference strain SR49 (serotype 3) which is associated with inclusion body hepatitis in chickens. This finding was confirmed by the virus neutralization test.

Investigation on intestinal bacterial flora and Salmonella spp. presence in organic and conventional chickens

Abstract The aim of this study was to evaluate the possible differences in the intestinal microflora composition among the different rearing systems (conventional vs organic) and the Salmonella diffusion using bacteriological techniques. The results showed that the differences between the two groups at the same age, expressed by the bacterial count, are not conclusive in showing an influence of the rearing systems. Salmonella Hadar was isolated once in caeca of conventional and once in caeca of organic ones. Though the results are preliminary and referred to a well defined geographic area in Central Italy, Salmonella detection does not seem to be common in conventional and organic chicken farms.

Plasma corticosterone levels in laying hens from three different housing systems: preliminary results

Abstract Adrenocortical and thyroidal hormones are physiological indicators of various forms of stress in the fowl. In order to establish possible variations in corticosterone levels, blood samples were collected from ISA Brown hens reared in three different housing systems (cage, floor and organic way). Results showed that corticosterone concentrations were highest in caged hens, intermediate in organic reared hens and lowest in floor reared hens. It could be assumed that in the last one system birds have an adequate space in controlled environment that permits them to satisfy, though partially, their behavioural needs without the presence of different chronic stress factors acting in the other systems.