From September 1994 to April 1996, the aetiology of sudden decrease in egg production in commercial layer flocks was investigated. Clinical manifestations were recorded and the egg-shell quality was evaluated in 80 affected flocks. Serological screening was conducted twice at fortnightly intervals to record antibody titres against egg drop syndrome (EDS). Out of 80 flocks with lowered productio...

The coordinated flight of bird flocks is a pleasant and attractive sight. While most previous approaches have focused on animating cluster formations, this paper introduces a technique for animating flocks that fly in certain patterns (socalled line formations). We distinguish between the behavior of such flocks during initiation and their behavior during steady flight. We provide a biologicall...

BACKGROUD Mycoplasma synoviae (M. synoviae) is widely distributed around the world, and leads to serious economic losses in the world every year. Nevertheless, the incidence and epidemiology of M. synoviae infection in China have remained unclear. RESULTS In this study we demonstrate that over 9773 broiler chicken flocks in 16 Chinese provinces were affected by M. synoviae between 2010 and 20...

Avian reoviruses are members of the orthoreovirus genus in the Reoviridae family (4, 6). Ubiquitous in commercial poultry, they can be differentiated by antigenic configuration, pathotype, relative pathogenicity, growth in cell culture, sensitivity to trypsin, and host specificity (2, 3, 4, 5, 8, 9, 10, 11, 12).1 Reoviruses have been isolated from a variety of tissues in chickens affected by as...

Mycoplasma gallisepticum is the primary agent of chronic respiratory disease causing important economic losses in the poultry industry. Serological monitoring is essential to maintain mycoplasma-free breeder flocks and often complicated by the cross-reactions between different mycoplasma species. To overcome serological cross-reactions, a large fragment of the M. gallisepticum PvpA cytadhesin, ...

In social groups, subordinates may gain dominant breeding status either by inheriting the top position in their current group or by dispersing to join a new group. The pathway to breeder status is likely to vary between males and females as a result of sex differences in the costs of dispersal and inbreeding. We report results from a field study conducted to explore sex differences in the rates...

Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) has been associated with morbidity and mortality in broiler chickens worldwide. The present study described purulent arthritis of broilers infected with Salmonella Enteritidis and investigated antibiograms and genetic characteristics of Salmonella Enteritidis isolates from epidemiologically related properties such as a hatchery an...

BACKGROUND This study was performed to demonstrate the widespread distribution and severity of selenium (Se) deficiency in sheep flocks and to evaluate the impact of influencing factors. In 150 flocks, ten serum samples of adult ewes were analysed for Se concentration. The farmers were interviewed concerning flock size, provision of mineral supplement, predominant form of husbandry (stationary ...

Two experiments were carried out to examine the interaction of egg storage period, egg position during storage, and turning frequency during subsequent incubation on fertile hatchability and embryonic mortality of broiler hatching eggs. Broiler hatching eggs from breeder flocks at 62 and 60 wk of age were stored for either 3 or 14 d at 18 degrees C and 75% RH in either the normal large end up o...

Avian encephalomyelitis is caused by an Hepatovirus and primarily affects chickens. Chickens of all ages are susceptible to the virus, but the nervous symptoms are manifested only in young chicks, between one to five weeks of age. During the last thirty years, avian encephalomyelitis appeared to be well controlled by breeder vaccination. However, the increase of the number of cases is causing c...