No differences were observed in the patterns of adrenal steroidogenesis in vitro by ducks maintained on fresh water or on a hypertonic salt solution. Determinations in vivo of the biological half-life of corticosterone showed no significant difference between ducks maintained on or loaded with saline and fresh water controls. An increase in the apparent volume of distribution of corticosterone was, however, observed in birds loaded with the salt solution after maintenance on fresh water or salt solution. Estimations were made of the secretory rate of corticosterone in vivo. In the ducks maintained on the salt solution an increased adrenal weight was responsible for the enhanced secretory rate but ducks maintained on fresh water and loaded with saline secreted corticosterone at a higher rate per unit weight of adrenal. The implications of the increased rate of corticosterone secretion are discussed in relation to the known dependence of nasal gland function in marine birds on a functional adrenal gland.

Prediction of genetic gains in body weight, egg production and shell quality traits in the Brown Tsaiya laying duck

cover as predictors of a weather severity index

in ducks (Anas platyrhynchos) during involuntary submergence.

Abstract: Captive mallard (Anas platyrhynchos) facilities are a common source of birds for game preserves. An outbreak of Escherichia coli septicemia in 2 and 8-wk-old ducklings was diagnosed in a captive mallard facility in South Georgia. Additionally, fungal hyphae were observed in the 2-wk

The influence of stress on the secretion of corticosterone has been investigated by radioimmunoassay in domestic ducks (Anasplatyrhynchos) of 6\p=n-\8 weeks ofage. Intravenous and i.m. injections of synthetic ACTH (Synacthen, 25 i.u./bird and Synacthen Depot, 100 i.u./bird respectively) markedly increased (2\m=.\7-to 10-fold) basal concentrations of corticosterone in plasma (3\p=n-\6 ng/ml) in comparison with those in birds injected with 0\m=.\9% saline (1 ml/bird). Maximum levels of 30\p=n-\40 ng/ml plasma were reached after 30 min and 5 h respectively. Increased levels of corticosterone in plasma were also seen within 5 min of i.v. administration of saline and remained as high as those in birds treated with Synacthen for at least 20 min after injection. Blood sampling (from the brachial vein) was, by itself, sufficient to increase levels ofcorticosterone in plasma; a large (twofold) rise being observed as soon as 1 min after initial handling and bleeding, with concentrations of 30\p=n-\40 ng/ml being found in birds bled 15 times during a period of 14 min. However, in a flock of birds, the alarm created in unhandled birds while others were being bled had no effect on concentrations of corticosterone in plasma. Deprivation of food or water for 24 h also enhanced levels of corticosterone in plasma, as did 24 h of adaptation to 0\m=.\2m-NaCl drinking water. These results have demonstrated the lability of the secretion of corticosterone in response to stress and demonstrated its usefulness as a physiological indicator of stress in ducks.

Summary: This study aimed to observe the air sacs (Sacci pneumatici) in mature Mallard ducks (Anas platyrhynchos). After animals (n=9) were euthanased by combination of ketamine 60 mg/kg and xylazine 6 mg/kg, methylmethacrylate (Takilon) was injected by way of trachea. They were put in a cold

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

and the origin of Mallard Anas platyrhynchos populations during the non-breeding season in Hungary. A large-scale monitoring study conducted on Lake Balaton and Kis-Balaton between 2003 and 2007 showed that population sizes fluctuated seasonally and peaked during winter months (December–January), with around 10

The study was carried to identify the phenotypic variation of Alabio duck (Anas platyrhynchos Borneo) being kept by smallholder. This research was conducted in Hulu Sungai Selatan (HSS), Hulu Sungai Tengah (HST) and Hulu Sungai Utara (HSU), South Kalimantan from May until November 2009. Six