Lactobacillus acidophilus and Bacillus subtilis significantly change the growth performance, serum immunity and cecal microbiota of Cherry Valley ducks during the fattening period.

This study explored the effects of a Bacillus subtilis and Lactobacillus acidophilus mixture containing the co-fermented products of the two probiotics on growth performance, serum immunity and cecal microbiota of Cherry Valley ducks. This study included 480 one-day-old Cherry Valley ducks divided into four feeding groups: basal diet (control group) and basal diet supplemented with 300, 500, or 700 mg/kg of the probiotic powder; the ducks were raised for 42 days. Compared with the control group, body weight on day 42 and the average daily gain on days 15-42 significantly increased (p < 0.05), and the feed conversion rate significantly decreased (p < 0.05) in the experimental groups. Furthermore, the serum immunoglobulin (Ig) A, IgG, IgM, and interleukin (IL)-4 levels increased significantly (p < 0.05), and IL-1ß, IL-2, and tumor necrosis factor-α decreased significantly (p < 0.05) in the experimental groups. Finally, Sellimonas, Prevotellaceae NK3B31 group, Lachnospiraceae NK4A136 group and Butyricoccus played an important role in the cecal microbiota of the experimental group. Thus, the probiotic powder has impacts on the growth performance, serum immunity and cecal microbiota of Cherry Valley Ducks.

Magnolol additive improves growth performance of Linwu ducklings by modulating antioxidative status.

Magnolol is a bioactive polyphenolic compound commonly found in Magnolia officinalis. The aim of this study is to clarify the contribution of the magnolol additive on the growth performance of Linwu ducklings aging from 7 to 28 d, comparing to the effects of antibiotic additive (colistin sulphate). A total of 325, 7-d-old ducklings were assigned to 5 groups. Each group had 5 cages with 13 ducklings in each cage. The ducklings in different groups were fed with diets supplemented with 0, 100, 200 and 300 mg/kg magnolol additive (MA) (Control, MA100, MA200 and MA300) and 30 mg/kg colistin sulphate (CS30) for 3 weeks, respectively. Parameters regarding to the growth performance, intestinal mucosal morphology, serum biochemical indices, antioxidant and peroxide biomarkers and the expression levels of antioxidant-related genes were evaluated by one way ANOVA analysis. The results showed that 30 mg/kg colistin sulphate, 200 and 300 mg/kg magnolol additive improved the average final weight (P = 0.045), average daily body weight gain (P = 0.038) and feed/gain ratios (P = 0.001) compared to the control group. 200 and 300 mg/kg magnolol additive significantly increased the villus height/crypt depth ratio of ileum, compared to the control and CS30 groups (P = 0.001). Increased serum level of glucose (P = 0.011) and total protein (P = 0.006) were found in MA200 or MA300 group. In addition, comparing to the control and CS30 groups, MA200 or MA300 significantly increased the levels of superoxide dismutase (P = 0.038), glutathione peroxidase (P = 0.048) and reduced glutathione (P = 0.039) in serum. Moreover, the serum and hepatic levels of 8-hydroxy-2'-deoxyguanosine (P = 0.043 and 0.007, respectively) were lower in all MA groups compared to those of the control and CS30 group. The hepatic mRNA expression levels of superoxide dismutase-1, catalase and nuclear factor erythroid-2-related factor 2/erythroid-derived CNC-homology factor were also increased significantly in MA200 and MA300 groups (P < 0.05). Taken together, these data demonstrated that MA was an effective feed additive enhancing the growth performance of Linwu ducklings at 7 to 28 d by improving the antioxidant and intestinal mucosal status. It suggested that MA could be a potential ingredient to replace the colistin sulphate in diets.

Estimation of dietary zinc requirement for laying duck breeders: effects on productive and reproductive performance, egg quality, tibial characteristics, plasma biochemical and antioxidant indices, and zinc deposition.

This study evaluated the effects of different dietary zinc (Zn) levels on productive and reproductive performance, egg quality, tibial characteristics, plasma biochemical and antioxidant indices, and zinc deposition in laying duck breeders. A total of 504 Longyan duck breeders aged 21 wk were randomly allocated to 6 treatments and fed a basal diet (Zn, 27.7 mg/kg) or that basal diet supplemented with Zn (as ZnSO4·H2 O) at 10, 20, 40, 80, or 160 mg Zn per kg of feed for 20 wk. Each group had 6 replicates of 14 ducks each. Dietary Zn supplementation affected (P < 0.05) the egg production, FCR, and shell thickness of laying duck breeders from 21 to 40 wk, and there was a quadratic (P < 0.05) effect between them. Dietary Zn supplementation affected (P < 0.05) and quadratically (P < 0.001) increased the breaking strength, density, and dry defatted weight of tibias. Alkaline phosphatase, calcium, phosphorus, total superoxide dismutase, glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) activities or content in plasma were affected (P < 0.05), and quadratically (P < 0.01) changed by dietary Zn levels. Dietary Zn supplementation affected (P < 0.01) and increased the Zn deposition in egg yolk (linear, P < 0.05; quadratic, P < 0.001) and tibia (linear, P < 0.05). The dietary Zn requirements, in mg/kg for a basal diet containing 27.7 mg/kg Zn, for Longyan duck breeders from 21 to 40 wk of age were estimated to be 65.4 for optimizing egg production, 68.6 for FCR, 102 for hatchling BW, 94.7 for eggshell thickness, 77.2 for tibial breaking strength, 81.4 for tibial density, 78.9 for tibial dry defatted weight, 69.5 for plasma GSH-Px activity, 72.4 for plasma MDA content, and 94.6 for Zn content in tibia. Overall, dietary Zn supplementation, up to 160 mg/kg feed, affected the productive performance, eggshell thickness, tibial characteristics, plasma antioxidant status, and Zn deposition of layer duck breeders. Supplementing this basal diet (27.7 mg/kg Zn) with 70 to 80 mg/kg additional Zn was adequate for laying duck breeders during the laying period.

Pharmacokinetics and pharmacodynamics of alfaxalone after a single intramuscular or intravascular injection in mallard ducks (Anas platyrhynchos).

Pharmacokinetics and pharmacodynamics of alfaxalone was performed in mallard ducks (Anas platyrhynchos) after single bolus injections of 10 mg/kg administered intramuscularly (IM; n = 10) or intravenously (IV; n = 10), in a randomized cross-over design with a washout period between doses. Mean (±SD) Cmax following IM injection was 1.6 (±0.8) µg/ml with Tmax at 15.0 (±10.5) min. Area under the curve (AUC) was 84.66 and 104.58 min*mg/ml following IV and IM administration, respectively. Volume of distribution (VD ) after IV dose was 3.0 L/kg. The mean plasma clearance after 10 mg/kg IV was 139.5 (±67.9) ml min-1  kg-1 . Elimination half-lives (mean [±SD]) were 15.0 and 16.1 (±3.0) min following IV and IM administration, respectively. Mean bioavailability at 10 mg/kg IM was 108.6%. None of the ducks achieved a sufficient anesthetic depth for invasive procedures, such as surgery, to be performed. Heart and respiratory rates measured after administration remained stable, but many ducks were hyperexcitable during recovery. Based on sedation levels and duration, alfaxalone administered at dosages of 10 mg/kg IV or IM in mallard ducks does not induce clinically acceptable anesthesia.

Effect of dietary graded resistant potato starch levels on growth performance, plasma cytokines concentration, and intestinal health in meat ducks.

The objective of the present study was to investigate the effect of dietary graded raw potato starch (RPS) levels on growth performance, plasma cytokines concentration, ileal barrier function, and cecal short-chain fatty acids (SCFA) concentration in meat ducks from 1 to 35 D of age. This study included 2 experiments. In experiment (Exp.) 1, sixteen 35-day-old meat ducks were used to evaluate the AME of RPS by orogastric administration. Results showed the AME value of RPS on ducks is 2.76 kcal/g. In Exp. 2, a total of 600 one-day-old ducklings were randomly assigned to 5 isonitrogenous and isoenergetic dietary treatments that included 0 (control), 6, 12, 18, and 24% RPS, respectively. Samples were collected at both of 14 and 35 D. Neither growth performance nor ileal parameters (length, weight, and pH) at both of 14 and 35 D was affected by dietary RPS. However, the mucosal thickness (14 D), villus height (except for 18% RPS at 14 D), and the villus height: crypt depth ratio (14 and 35 D) of the ileum were increased in the 12 and 18% RPS diets when compared to 0% RPS diet. Meanwhile, proinflammatory factors such as plasma interleukin (IL)-1ß and IL-6 (14 D) reduced in 12% RPS diet and tumor necrosis factor α decreased in 12% (except for 14 D) and 18% RPS groups. When compared with the control group, diets with 18% RPS significantly increased mucin 2 gene expression at 14 D, and 12% RPS elevated the mRNA expression of tight junction proteins including Zonula occludens-1 and Claudin 1 (except for 14 D) in the ileal mucosa of birds. Furthermore, ducks fed 12% RPS diet had higher concentrations of acetate, propionate, and butyrate in cecal digesta than other groups. These findings indicated that diets with 12 and/or 18% RPS increased the cecal SCFA concentration, which subsequently enhanced the barrier function and improved intestinal health in the ileum for 14 and 35-day-old meat ducks.

Fermentation of flaxseed cake increases its nutritional value and utilization in ducklings.

Flaxseed cake (FSC) is a potential alternative feed source in poultry. However, cyanogenetic glycosides limit its widespread use in feed. In this study, we optimized the parameters of fermentation by Aspergillus niger and Candida utilis and compared the growth performance, serum lipid parameters, and organ indexes of Cherry Valley duckling feed with unfermented FSC (UFSC) or fermented FSC (FFSC). A total of 420 one-day-old male Cherry Valley ducklings were randomly assigned into a 1 plus 2 × 3 factorial design including 2 different FSC resources (UFSC and FFSC) at 3 levels (50, 100, or 150 g/kg) for 3 wk. Each treatment group included 6 pens with 10 ducklings per pen. The hydrocyanic acid (HCN) level was reduced under the following conditions: 1:0.8 FSC:water (w:v), inoculum ratio of 1 mL:1 mL, 30°C, and 60 h. FFSC had higher crude protein (CP) and calcium (Ca) levels and lower HCN levels compared with UFSC (P < 0.05). There was no interactive effect between FSC sources and levels on growth performance. Final body weight (FBW), average daily feed intake (ADFI), and average daily gain (ADG) in UFSC groups and ADFI in FFSC groups decreased linearly with increasing FSC levels (P < 0.01). There were no differences in FBW, ADG, or feed:gain ratio (F/G) among FFSC groups, and all 7 FSC groups had no differences in the F/G ratio (P > 0.05). Dietary FSC supplementation decreased triglyceride (TG) (P < 0.01), total cholesterol (TC) (P < 0.01), high-density lipoprotein (HDL) (P = 0.01), and low-density lipoprotein (LDL) (P < 0.01). No interactive effect between FSC levels and sources was observed for serum TG, TC, HDL, or LDL. Ducklings fed FFSC had lower TG (P < 0.01), TC (P = 0.05), and LDL (P < 0.01) levels compared with ducklings fed UFSC. The 150 g/kg FFSC group had the lowest TG, TC, HDL, and LDL levels among all 7 groups. Flaxseed cake supplementation decreased the relative weight of the left breast, but FFSC increased the relative weight of the gizzard compared with UFSC. In conclusion, fermentation could increase the nutritional value and usage of FSC in ducklings.

Venous Blood Analytes and Osmolality of Rehabilitated Juvenile Black-bellied Whistling Ducks (Dendrocygna autumnalis).

Venous blood samples were collected from 129 apparently healthy, rehabilitated juvenile black-bellied whistling ducks (Dendrocygna autumnalis) immediately before release from rehabilitation. Blood gas, electrolyte, and select biochemical and hematologic values were analyzed by using a point-of-care analyzer, and complete blood cell counts and osmolality were determined. Most biochemical analyte values were distributed parametrically, while most hematologic values were nonparametrically distributed. Calculated osmolality values were in poor agreement with measured osmolality values, and values of packed cell volume had poor agreement with hematocrit values determined with the i-STAT 1. The physiologic values reported provide vital information to assess individual duck health and guide fluid therapy in captivity and may prove useful to assess free-living population health of this duck species.

The nutritive value of cassava starch extraction residue for growing ducks.

The cassava root meal (CRM) has been utilized as a cheap energy alternative to replace maize in poultry diets. Recently, the CRM in turn has an increasing demand for starch extraction industry, which renders large amounts of residues. This study evaluated the nutrient composition, amino acid profile, and feeding value of cassava starch extraction residue meal (CReM) for growing ducks. A total of 960, 11-day-old, ducklings were housed in 24 floor pens and allocated randomly into four dietary treatments: (i) 0CReM (control), (ii) 50 g CReM/kg, (iii) 100 g CReM/kg, and (iv) 150 g CReM/kg. The analyses (/kg) of CReM showed high gross energy (3306.88 kcal), ME (2109.54 kcal), and starch (514.0 g), with poor crude protein (20.9 g) and moderate crude fiber (140.0 g) and ash (60.0 g) contents. The total amino acid (AA) content amounted to 19.9 g/kg of CReM DM, in which the methionine, lysine, cystine, and isoleucine were present in low levels. The dietary inclusion of CReM up to 150 g/kg, between 11 and 42 days of age, had no significant effects (P > 0.05) on duck growth parameters, mortality, dressed weight, internal organs, or abdominal fat. Besides, the tested CReM levels did not show any significant effect on the blood proteins or liver enzymes. The results, therefore, revealed that the CReM contains a considerable amount of energy and could be incorporated successfully up to 150 g/kg in the diets of growing ducks.

A comparison of Mott cell morphology of three avian species. II. - Bad behavior by plasmacytes?

Mott cells are atypical plasmacytes recognized microscopically by endoplasmic reticulum (ER) distensions (Russell bodies) a result of retained secretory product (antibody). Originally associated with parasitism, they are observed in a broad spectrum of immunopathology, sometimes involving hypergammaglobulinemia. Few descriptions of Mott cells appear in avian literature. The purpose of the manuscript is to provide examples identified by light microscopy in three poultry species. Transmission electron micrographs (TEM) of plasmacytes from the turkey oviduct mucosa are included for comparison with Mott cell light microscopic images. Wright's stained blood and bone marrow from commercial and specific pathogen free (SPF) chickens, ducks, and turkeys are the sources. Mott cell positive samples commonly occurred with leukocytosis or leukemoid reactions, polymicrobial bacteremia, and fungemia. Atypical granulocytes and leukocytes regularly accompanied Mott cells. It is proposed that circulating Mott cells are "sentinels" indicative of stress, dyscrasia, and pathology. Moreover, Mott cells, like other atypia, complicate the interpretation of simple heterophil/lymphocyte (H/L) ratios. As Mott cells are defective plasmacytes these observations address hematology, immunology, pathology, and welfare issues.

Cadmium-induced changes in hatchability and in the activity of aminotransaminases and selected lysosomal hydrolases in the blood plasma of Muscovy ducklings (Cairina moschata).

The aim of this study was to determine the effect of cadmium on Muscovy ducklings (Cairina moschata) based on hatching results and the activity of enzymes in the blood plasma. On day 6 of incubation, hatching eggs were injected into the egg albumen with 50 µl of saline solution containing Cd ions (CdCl2) at concentrations of 0 (control group), 1.3, 4.0, 7.5, 15.0 and 30 µg/egg, using 50 eggs per group. A gradual decrease in hatchability, from 52% in the control to 4% in the highest Cd dose group, was observed, with the LD50 calculated as 8 µg/egg. However, the impact of cadmium on the incidence of malformations of duck embryos has not been proven. Compared to the control group, N-acetyl-ß-Dglucosaminidase activity increased by 30-50% (P ≤ 0.05) in the blood serum of ducklings in the groups receiving more than 7.5 µg Cd/egg, whereas an elevated activity of arylsulphatase (by 45%) was observed for a lower dose only (4 µg Cd/egg). A gradual increase in the activity of alanine and aspartate aminotransferases was observed (P ≤ 0.05), starting from the lowest exposure of 1.3 µg Cd/egg, by 155% and 53%, respectively. In conclusion, the results prove the dosedependent toxic impact of cadmium on embryogenesis and on the studied blood plasma enzyme activities of ducklings.

Response of the hepatic transcriptome to aflatoxin B1 in ducklings.

This study was conducted to determine the effects of aflatoxin B1 (AFB1) on the hepatic transcriptome in ducklings through RNA-sequencing (RNA-Seq). Twenty four, 1-day-old ducklings were divided into 4 treatment groups. Each group received an oral dose of AFB1 at 0, 10, 20, 40 µg/kg BW per day for 2 weeks. Administration of 20 and 40 µg/kg BW of AFB1 significantly decreased body weight, feed intake, serum total protein and albumin, while increasing serum aspartate aminotransferase and alanine aminotransferase activities, and hepatic histopathological lesions. Furthermore, RNA was extracted from the liver of ducklings administrated 0 and 40 µg/kg BW of AFB1. Two RNA-Seq libraries were created from pooled samples and produced over 149 M reads, totaling 14.9 Gb of sequence. Approximately 96,953 predicted transcripts were assembled, 749 of which had significant differential expressions (≥ 2-fold) between the control and AFB1 treatment. GO and KEGG pathway analysis results showed that many genes involved in phase I metabolism, phase II detoxification, oxidation-reduction process, carcinogenesis, apoptosis and cell cycle, and fatty acid metabolism were affected by AFB1 exposure. Conclusion, this study determined the hepatic transcriptome responded to AFB1 exposure, and provide candidate genes can be targeted to prevent and/or reduce aflatoxicosis in ducklings.

Development of highly sensitive and specific mRNA multiplex system (XCYR1) for forensic human body fluids and tissues identification.

The identification of human body fluids or tissues through mRNA-based profiling is very useful for forensic investigations. Previous studies have shown mRNA biomarkers are effective to identify the origin of biological samples. In this study, we selected 16 tissue specific biomarkers to evaluate their specificities and sensitivities for human body fluids and tissues identification, including porphobilinogen deaminase (PBGD), hemoglobin beta (HBB) and Glycophorin A (GLY) for circulatory blood, protamine 2 (PRM2) and transglutaminase 4 (TGM4) for semen, mucin 4 (MUC4) and human beta defensin 1(HBD1) for vaginal secretion, matrix metalloproteinases 7 and 11 (MMP7 and MMP11) for menstrual blood, keratin 4(KRT4) for oral mucosa, loricrin (LOR) and cystatin 6 (CST6) for skin, histatin 3(HTN3) for saliva, statherin (STATH) for nasal secretion, dermcidin (DCD) for sweat and uromodulin (UMOD) for urine. The above mentioned ten common forensic body fluids or tissues were used in the evaluation. Based on the evaluation, a reverse transcription (RT) PCR multiplex assay, XCYR1, which includes 12 biomarkers (i.e., HBB, GLY, HTN3, PRM2, KRT4, MMP11, MUC4, DCD, UMOD, MMP7, TGM4, and STATH) and 2 housekeeping genes [i.e., glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and 18SrRNA], was developed. This assay was further validated with real casework samples and mock samples (with both single source and mixture) and it was approved that XCYR1 is effective to identify common body fluids or tissues (i.e., circulatory blood, saliva, semen, vaginal secretion, menstrual blood, oral mucosa, nasal secretion, sweat and urine) in forensic casework samples.

Health of domestic mallards (Anas platyrhynchos domestica) following exposure to oil sands process-affected water.

Bitumen extraction from the oil sands of northern Alberta produces large volumes of process-affected water that contains substances toxic to wildlife. Recent monitoring has shown that tens of thousands of birds land on ponds containing this water annually, creating an urgent need to understand its effects on bird health. We emulated the repeated, short-term exposures that migrating water birds are thought to experience by exposing pekin ducks (Anas platyrhynchos domestica) to recycled oil sands process-affected water (OSPW). As indicators of health, we measured a series of physiological (electrolytes, metabolites, enzymes, hormones, and blood cells) and toxicological (metals and minerals) variables. Relative to controls, juvenile birds exposed to OSPW had higher potassium following the final exposure, and males had a higher thyroid hormone ratio (T3/T4). In adults, exposed birds had higher vanadium, and, following the final exposure, higher bicarbonate. Exposed females had higher bile acid, globulin, and molybdenum levels, and males, higher corticosterone. However, with the exception of the metals, none of these measures varied from available reference ranges for ducks, suggesting OSPW is not toxic to juvenile or adult birds after three and six weekly, 1 h exposures, but more studies are needed to know the generality of this result.

Marbofloxacin disposition after intravenous administration of a single dose in wild mallard ducks (Anas platyrhynchos).

Marbofloxacin, a fluoroquinolone developed specifically for veterinary use, has demonstrated considerable pharmokinetic variation among avian species. The goal of this study was to determine the disposition kinetics of marbofloxacin in mallard ducks (Anas platyrhynchos) after a single intravenous injection. Six wild mallard ducks were used in the study. Marbofloxacin was injected at a dose of 2 mg/kg into the basilic vein, and blood was subsequently collected at regular intervals from each bird. Plasma marbofloxacin concentrations were determined by using high-performance liquid chromatography. The volume of distribution at steady state was 1.78 +/- 0.37 L/kg, and the total plasma clearance was 0.59 +/- 0.08 L/kg per hour. Marbofloxacin had a relatively short permanence, with a elimination half-life of 2.81 +/- 1.20 hours, a terminal half-life of 2.43 +/- 0.61 hours, and a mean residence time of 2.99 +/- 0.52 hour. The maximum observed concentration (Cmax) and area under the curve (AUC) were 1.34 +/- 0.27 microg/mL and 3.75 +/- 0.56 microg x h/mL, respectively. Values of minimum inhibitory concentration (MIC), Cmax, and AUC have been used to predict the clinical efficacy of a drug in treating bacterial infections, with a Cmax: MIC value of 10 and an AUC: MIC ratio of 125-250 associated with optimal bactericidal effects. By using the study data and MIC breakpoints of 0.125 microg/mL or 0.2 microg/mL, values derived for Cmax: MIC were 9.37 +/- 0.99 and 5.85 +/- 0.62, respectively, and for AUC: MIC were 29.99 +/- 4.51 and 18.74 +/- 2.82, respectively. By using MIC values of 0.125 and 0.2 microg/mL and a target AUC: MIC = 125, the calculated optimal daily marbofloxacin dosages for mallard ducks were 9.24 and 14.78 mg/kg, respectively. These results suggest that, primarily because of the high total plasma clearance observed, the marbofloxacin dose for treatment of bacterial diseases in mallard ducks should be increased after intravenous administration. Intravenous doses of 10-15 mg/kg should be assessed by studying their potential toxicity and efficacy in sick birds.

Selenium concentrations and enzyme activities of glutathione metabolism in wild long-tailed ducks and common eiders.

The relationships of selenium (Se) concentrations in whole blood with plasma activities of total glutathione peroxidase, Se-dependent glutathione peroxidase, and glutathione reductase were studied in long-tailed ducks (Clangula hyemalis) and common eiders (Somateria mollissima) sampled along the Beaufort Sea coast of Alaska, USA. Blood Se concentrations were >8 µg/g wet weight in both species. Linear regression revealed that the activities of total and Se-dependent glutathione peroxidase were significantly related to Se concentrations only in long-tailed ducks, raising the possibility that these birds were experiencing early oxidative stress.

Effects of vitamin C supplementation on growth performance and antioxidant status of layer ducklings.

The study was conducted to evaluate the effects of increasing dietary vitamin C supplements on growth performance, antioxidant status and humoral immunity of layer ducklings. The results showed that the body weight and daily body weight gain of ducklings increased (p < 0.05) with increasing dietary vitamin C supplementations and reached a maximum at 400 mg vitamin C/kg feed. The dietary vitamin C supplementations reduced the malondialdehyde concentration (p < 0.05) and increased the activities of superoxide dismutase and glutathione peroxidase (p < 0.05) in serum and liver of ducklings at day 5 and 28. Additionally, feeding 400 mg/kg or 800 mg vitamin C/kg feed increased IgM and IgA concentrations in sera (p < 0.05) and serum IgG concentrations increased (p < 0.05) following supplementation in concentrations of 150-800 mg vitamin C/kg feed. In conclusion, the results suggested that dietary vitamin C supplements of 400 mg/kg feed provide optimal effects on growth performance, antioxidant status and parameters of humoral immunity.

PCB exposure in sea otters and harlequin ducks in relation to history of contamination by the Exxon Valdez oil spill.

Exposure to contaminants other than petroleum hydrocarbons could confound interpretation of Exxon Valdez oil spill effects on biota at Prince William Sound, Alaska. Hence, we investigated polychlorinated biphenyls (PCBs) in blood of sea otters and harlequin ducks sampled during 1998. PCB concentrations characterized by lower chlorinated congeners were highest in sea otters from the unoiled area, whereas concentrations were similar among harlequin ducks from the oiled and unoiled area. Blood enzymes often elevated by xenobiotics were not related to PCB concentrations in sea otters. Only sea otters from the unoiled area had estimated risk from PCBs, and PCB composition or concentrations did not correspond to reported lower measures of population performance in sea otters or harlequin ducks from the oiled area. PCBs probably did not influence limited sea otter or harlequin duck recovery in the oiled area a decade after the spill.

Cadmium- and lead-induced apoptosis in mallard erythrocytes (Anas platyrhynchos).

Cadmium, lead and cadmium-lead (1:10) induced apoptosis were studied using mallard blood cells. The allowable range in concentrations were: 0.01-0.5, 0.1-5.0, and 0.01:0.10-0.50:5.00 mM, for cadmium, lead and cadmium-lead, respectively. The lowest EC(50) achieved was for cadmium (0.22+/-0.04 mM). Two doses from each treatment group were chosen to study apoptosis and the presence of metals in cells. The percentage of apoptotic cells increased as the concentration of metals increased. The percentage of cells with intracellular metals was high for both exposure levels and the quantity of intracellular metal was greater for exposure to high concentrations. Morphological alterations for all types of exposure were related to the diverse range of effects that these metals have on membranes. We suggest that the decrease in the number of erythrocytes observed in specimens suffering from lead and cadmium poisoning is related to the induction of apoptosis.

A blood survey of elements, viral antibodies, and hemoparasites in wintering Harlequin Ducks (Histrionicus histrionicus) and Barrow's Goldeneyes (Bucephala islandica).

Twenty-eight Harlequin Ducks (Histrionicus histrionicus) and 26 Barrow's Goldeneyes (Bucephala islandica) were captured in Prince William Sound, Alaska, between 1 and 15 March 2005. Blood was collected for quantification of element concentrations, prevalence of antibodies to several viruses, and hemoparasite prevalence and identification. Although we found selenium concentrations that have been associated with selenosis in some birds (>or=2.0 ppm ww), our findings contribute to a growing literature describing relatively high selenium in apparently healthy birds in marine environments. Avian influenza virus antibodies were detected in the plasma of 28% of the ducks. No antibodies against adenovirus, reovirus, or paramyxovirus 1 were detected. Several hemo-parasite species were identified in 7% of ducks. Our findings are similar to those in other free-living marine waterfowl and do not indicate unusual concerns for the health of these species in this area in late winter.

Effects of ACTH, capture, and short term confinement on glucocorticoid concentrations in harlequin ducks (Histrionicus histrionicus).

Little is known about baseline concentrations of adrenal hormones and hormonal responses to stress in sea ducks, although significant population declines documented in several species suggest that sea ducks are exposed to increased levels of environmental stress. Such declines have been observed in geographically distinct harlequin duck populations. We performed an adrenocorticotropic hormone (ACTH) challenge to evaluate adrenal function and characterize corticosterone concentrations in captive harlequin ducks and investigated the effects of capture, surgery, and short term confinement on corticosterone concentrations in wild harlequin ducks. Harlequin ducks responded to the ACTH challenge with an average three-fold increase in serum corticosterone concentration approximately 90 min post injection, and a four- to five-fold increase in fecal glucocorticoid concentration 2 to 4 h post injection. Serum corticosterone concentrations in wild harlequin ducks increased within min of capture and elevated levels were found for several hours post capture, indicating that surgery and confinement maintain elevated corticosterone concentrations in this species. Mean corticosterone concentrations in wild harlequin ducks held in temporary captivity were similar to the maximum response levels during the ACTH challenge in captive birds. However, large variation among individuals was observed in responses of wild birds, and we found additional evidence suggesting that corticosterone responses varied between hatch year and after hatch year birds.