Centennial Review: History and husbandry recommendations for raising Pekin ducks in research or commercial production.

By some accounts, ducks were domesticated between 400 and 10,000 yr ago and have been a growing portion of the poultry industry for decades. Ducks specifically, and waterfowl in general, have unique health, housing, nutrition and welfare concerns compared to their galliform counterparts. Although there have been many research publications in regards to health, nutrition, behavior, and welfare of ducks there have been very few reviews to provide an overview of these numerous studies, and only one text has attempted to review all aspects of the duck industry, from breeders to meat ducks. This review covers incubation, hatching, housing, welfare, nutrition, and euthanasia and highlights the needs for additional research at all levels of duck production. The purpose of this review is to provide guidelines to raise and house ducks for research as specifically related to industry practices.

A feed restriction milieu for Pekin meat ducks that may improve gait characteristics but also affects gut leakiness.

In a previous study, we demonstrated that a 15% feed restriction (FR) during the first 2 wk after hatch could improve gait in Pekin meat ducks, but did result in reduced breast mass. We hypothesized that feed restriction after day 5 following muscle satellite cell development would allow the full growth of the breast meat. To accomplish this goal, 300 1-day-old ducklings (Maple Leaf Farms Inc.) were randomly allocated to 1 of the 3 groups (n = 4 pens, 25 ducks per pen): (1) Control group fed to ad libitum; (2) 85% daily feed intake from days 1 to 14 (FR 85% 1-14); 85% daily feed intake from days 5 to 14 (FR 85% 5-14). All ducks were vaccinated with inactivated Salmonella enteritidis on day 14 and boosted on day 26. The FR 85% 5-14 did show similar production standards to controls, and improved gait characteristics (P < 0.05). To determine if the partial feed restriction would have an impact on intestinal epithelial tight junction integrity, we treated ducks on days 7, 14, 21, 28, and 35 with 8.32 mg/kg FITC-d in water per os and blood samples were obtained via the tibial vein 1 h later. Serum samples were analyzed for presence and quantification of FITC-d. Feed restriction elicited a significant increase in FITC-d permeability at all points of evaluation. Anti-S. enteritidis specific IgY responses were assessed by ELISA from serum collected at 14 D, 28 D, and 35 D. Although all ducks showed an increase humoral immune response to the S. enteritidis, both feed restricted groups showed reduced IgY production compared to ad lib controls. Our data suggest that although the FR 5-14 feed restriction paradigm may reduce gait abnormalities without affecting production rates, some challenges exist due to increased gut leakiness or decreased acquired immune activity. Future studies will look at altering the feed restriction milieu to ameliorate these challenges.

Functional evaluation of a PTSD-associated genetic variant: estradiol regulation and ADCYAP1R1.

Posttraumatic stress disorder (PTSD) affects 5-10% percent of the US adult population with a higher prevalence among women compared with men. Although it remains unclear how biological sex associates with susceptibility to PTSD, one mechanism may involve a role for estrogen in a gene by environment interaction. We previously demonstrated a sex-dependent association between the pituitary adenylate cyclase-activating polypeptide type 1 receptor (PAC1) and PTSD, where carriers of a C allele at single-nucleotide polymorphism (SNP) rs2267735 within the PAC1 receptor gene (ADCYAP1R1) have increased symptoms of PTSD. This SNP is located within a predicted estrogen response element (ERE), which regulates gene transcription when bound to estradiol (E2) activated estrogen receptor alpha (ERα). In the current study, we examined E2 regulation of ADCYAP1R1 in vitro, in cell culture, and in vivo in mice and humans. We find in mice that fear conditioning and E2 additively increase ADCYAP1R1 expression. In vitro, we show that E2/ERα binds to the ADCYAP1R1 ERE, with less efficient binding to an ERE containing the C allele of rs2267735. In women with low serum E2, the CC genotype associates with lower ADCYAP1R1 expression, which further associates with higher PTSD symptoms. These findings lead to a model in which E2 induces the expression of ADCYAP1R1 through binding of ERα at the ERE as an adaptive response to stress. Inhibition of E2/ERα binding to the ERE containing the rs2267735 risk allele results in reduced expression of ADCYAP1R1, diminishing estrogen regulation as an adaptive stress response and increasing risk for PTSD.

Effects of dietary protein concentration on performance and nutrient digestibility in Pekin ducks during aflatoxicosis.

A 14-d study was conducted to determine the impact of dietary crude protein concentration on performance, serum biochemistry, and nutrient digestive functions in Pekin ducklings during aflatoxicosis. A total of 144 male Pekin ducklings were randomly allotted to 4 dietary treatments arranged in a 2×2 factorial with 2 crude protein (CP) (20 and 24% on an analyzed basis) with or without 0.2 mg/kg aflatoxin B1 (AFB1) (0.21 mg/kg analyzed). The AFB1 reduced BW gain, feed intake, and breast muscle weight by 33 to 43% (P<0.0001). Serum concentration of protein, glucose, and Ca were also decreased by AFB1 (P≤0.0015), while pancreatic activities of amylase and lipase were increased by AFB1 (P<0.005). Apparent N digestibility was not affected by dietary treatment, whereas apparent ileal digestible energy was reduced 7.6% by AFB1 (P=0.0003). Higher dietary CP improved BW gain, gain:feed ratio, and breast muscle weight (P≤0.021), and tended to improve feed intake (P=0.094), but did not improve serum measures, digestive enzyme activity, or nutrient digestibility. No statistical interaction of AFB1 by CP was observed for any measures. Results from the current study suggest that AFB1 at low concentration can significantly impair performance of Pekin ducklings primarily through inhibited feed intake, as well as influence nutrient digestion processes (jejunum morphology, digestive enzyme activity, and apparent energy digestibility). Higher dietary CP can improve growth performance of ducklings regardless of AF exposure, but did not interact with dietary AFB1 on performance, serum biochemistry, or nutrient digestion in Pekin ducklings from hatch to 14 d.

Soil humic-like organic compounds in prescribed fire emissions using nuclear magnetic resonance spectroscopy.

Here we present the chemical characterization of the water-soluble organic carbon fraction of atmospheric aerosol collected during a prescribed fire burn in relation to soil organic matter and biomass combustion. Using nuclear magnetic resonance spectroscopy, we observed that humic-like substances in fire emissions have been associated with soil organic matter rather than biomass. Using a chemical mass balance model, we estimated that soil organic matter may contribute up to 41% of organic hydrogen and up to 27% of water-soluble organic carbon in fire emissions. Dust particles, when mixed with fresh combustion emissions, substantially enhances the atmospheric oxidative capacity, particle formation and microphysical properties of clouds influencing the climatic responses of atmospheric aeroso. Owing to the large emissions of combustion aerosol during fires, the release of dust particles from soil surfaces that are subjected to intense heating and shear stress has, so far, been lacking.

Diagnostics of underwater electrical wire explosion through a time- and space-resolved hard x-ray source.

A time- and space-resolved hard x-ray source was developed as a diagnostic tool for imaging underwater exploding wires. A ~4 ns width pulse of hard x-rays with energies of up to 100 keV was obtained from the discharge in a vacuum diode consisting of point-shaped tungsten electrodes. To improve contrast and image quality, an external pulsed magnetic field produced by Helmholtz coils was used. High resolution x-ray images of an underwater exploding wire were obtained using a sensitive x-ray CCD detector, and were compared to optical fast framing images. Future developments and application of this diagnostic technique are discussed.

Quality of life improves among post-menopausal women who received bone augmentation during dental implant therapy.

Quality of life outcomes among patients receiving implants have been well studied, but little is known about the effects of bone augmentation in this therapy. The purpose of this paper was to assess quality of life changes among postmenopausal women receiving dental implants with bone augmentation during implant therapy. This was a prospective cohort study. 48 patients were recruited at the University of Connecticut Health Center and received one of three surgical augmentation methods: dehiscence repair; expansion alone; or expansion with dehiscence repair. The predictor variable was type of augmentation procedure. Quality of life measured by the Oral Health Impact Profile-14 (OHIP-14) was the outcome measure and was assessed prior to treatment, 1 week, 8 weeks and 9 months after surgery. Changes in OHIP-14 were evaluated by repeated measures analysis of variance. The mean initial OHIP-14 scores on total items checked were 4.6 (SD=3.0) and declined significantly to 2.0 (SD=2.0) at 9 months. The mean baseline severity score was 15.4 (SD=8.9) improving significantly to 7.5 (SD=7.6) at 9 months. Type of augmentation procedure did not affect quality of life. The participants' quality of life improved continuously from the pretreatment to the 9-month assessment, including improvements 1 week after implant placement.

Wildfire responses to abrupt climate change in North America.

It is widely accepted, based on data from the last few decades and on model simulations, that anthropogenic climate change will cause increased fire activity. However, less attention has been paid to the relationship between abrupt climate changes and heightened fire activity in the paleorecord. We use 35 charcoal and pollen records to assess how fire regimes in North America changed during the last glacial-interglacial transition (15 to 10 ka), a time of large and rapid climate changes. We also test the hypothesis that a comet impact initiated continental-scale wildfires at 12.9 ka; the data do not support this idea, nor are continent-wide fires indicated at any time during deglaciation. There are, however, clear links between large climate changes and fire activity. Biomass burning gradually increased from the glacial period to the beginning of the Younger Dryas. Although there are changes in biomass burning during the Younger Dryas, there is no systematic trend. There is a further increase in biomass burning after the Younger Dryas. Intervals of rapid climate change at 13.9, 13.2, and 11.7 ka are marked by large increases in fire activity. The timing of changes in fire is not coincident with changes in human population density or the timing of the extinction of the megafauna. Although these factors could have contributed to fire-regime changes at individual sites or at specific times, the charcoal data indicate an important role for climate, and particularly rapid climate change, in determining broad-scale levels of fire activity.

Nutrient and energy utilization in enzyme-supplemented starter and grower diets for White Pekin ducks.

The aim of this study was to determine the effect of enzyme supplementation on energy and nutrient utilization in White Pekin ducks fed starter and grower diets. In each of 2 experiments, 8 ducks were assigned to each starter or grower diet without or with enzyme supplementation at 1 g/kg of diet in a 2 x 2 factorial arrangement of treatments for a 120-h nutrient utilization assay. Starter and grower diets in experiment 1 contained 3.68 and 2.51% N, respectively, and 4.321 and 4.274 kcal/ g of gross energy, respectively. Corresponding values in experiment 2 were 2.93 and 2.89% and 3.994 and 3.930 kcal/g. The enzyme supplement was a cocktail containing 7,500 units of protease and 44 units of cellulase per gram. Endogenous energy losses were from 23 to 44 kcal in the 2 experiments, and endogenous amino acid (AA) losses ranged from 14 mg for Trp to 137 mg for Asp. In experiment 1, a lower energy output of ducks fed the grower diet, coupled with lower N output, resulted in greater (P < 0.05) diet AME(n) for the grower than the starter diet. Apparent digestibilities of all AA were higher (P < 0.05) in the starter diet than in the grower diet regardless of enzyme supplementation, more so for the S-containing AA. Average true digestibility of all AA was 93.7 and 90.4% for the starter and grower diets, respectively. There was no effect of enzyme supplementation of diet on the true digestibility of AA except for Met. Average true digestibility of all AA for diets not supplemented or supplemented with enzyme were 91.3 and 92.8%, respectively. In experiment 2, energy utilization of the grower diet was higher (P < 0.05) than that of the starter diet. Lysine and Asp showed lower (P < 0.05) apparent digestibility in the grower than in the starter diet. Enzyme supplementation of starter or grower diets did not affect the apparent digestibility of AA, except for Met, whose digestibility was increased by 2.4 percentage points in an enzyme-supplemented diet (P < 0.05). Except for Trp, true digestibility of AA was not affected by diet type or enzyme supplementation. The results show that the enzyme cocktail evaluated improved AA and energy utilization in White Pekin ducks and that such an enzyme-related response is diet composition-dependent.

Comparison of five different abdominal access trocar systems: analysis of insertion force, removal force, and defect size.

Trocar designs have evolved in response to concerns about complication rates and surgical ergonomics. Functional properties of trocar systems that can be objectively measured include insertion force, removal force and the size of the tissue defect. This study will evaluate these properties in 5 common trocar designs. A porcine model was used to evaluate five different trocar systems for insertion force, removal force, and functional and measured tissue defect. Insertion force was lowest for cutting trocars and highest for radially dilating trocars. Removal force was similar for all trocars. Functional and measured tissue defect size was smallest for the hybrid type and radially dilating trocars. An ideal trocar system incorporates a low insertion force, secure retention, and a minimal tissue defect. Of the systems we tested, the hybrid type trocar has similar wound characteristics to the radially dilating trocar with the benefit of reduced insertion force. Further study is required to determine if these properties translate to an actual improvement in patient outcome.

Characterization of alkaline hydroxide-preserved whole poultry as a dry byproduct meal.

Studies were conducted to examine the chemical preservation of whole broiler carcasses by using aqueous alkaline hydroxide solutions. Conversion of the preserved carcasses and solutions into an acceptable poultry byproduct meal was examined. Carcasses and alkaline solutions at a 1:1 ratio were blended and freeze-dried to produce a high fat whole poultry byproduct meal. The dry meal was analyzed for nutrient composition, true metabolizable energy, and amino acid content. Viable bacteria were not recovered after inoculation of the experimental meal with Salmonella enteritidis. The meal was incorporated at 5 and 10% of chick starter diets. Chicks found the meal-containing diets acceptable. Feed consumption, water consumption, BW, and mortality were not significantly different among the dietary treatments in either of the two feeding trials. Necropsy samples revealed no pathological or histological differences attributable to consumption of the alkaline poultry byproduct and blood serum evaluation found no variation in blood chemistry. Alkaline treatment of whole broiler carcasses was an effective preservation method and acceptable as a dry poultry byproduct meal.

Rapid and complete adsorption of unconjugated protein from protein-polysaccharide conjugate vaccines.

We have developed a rapid and inexpensive approach to remove unconjugated protein from protein-polysaccharide conjugate vaccines, without using gel filtration or ultrafiltration. We employ porous particles that adsorb the protein, whether bound or free, but with a pore size that allows only the unconjugated protein to enter the particle. Using limited amounts of media there is preferential binding of the unconjugated protein over the high molecular weight protein-polysaccharide conjugate. Adsorption of the unconjugated protein is rapid, with greater than 90% recovery of the conjugate. The approach is applicable to both neutral and charged polysaccharides and is not dependent on the chemistry used to make the conjugate vaccine. We have used this method to prepare tetanus toxoid-polysaccharide conjugates and found their immunogenicity in mice comparable to conjugates prepared using gel filtration. The method described can be used to reduce the cost and increase the yields of protein-polysaccharide conjugate vaccines.

Growth curve analyses in selected duck lines.

1. Growth patterns of male ducks from 4 lines (lines A, B, C and D) selected for market weight were analysed and compared to growth patterns of ducks in the respective line 7 generations earlier. Growth curves were analysed using procedures derived from the Weibull sigmoidal function and the linear-linear relative growth rate model and simple allometry. 2. The ducks were fed ad libitum under 24-h lighting throughout the experiment. At weekly intervals from the time of hatch through 70 d of age, 16 ducks from each line were killed to determine body, carcase, breast-muscle, leg and thigh-muscle, and abdominal fat weights. 3. Line A was the heaviest line, followed by line B, line C and line D. However, body weight, carcase weight and breast-muscle weight at 49 d of age were not significantly different between lines A and B. After 7 generations of selection, the breast-muscle yield was increased to >19% and the abdominal fat percent was reduced to <1.4% in all lines. 4. The Weibull growth curve analysis of body weight showed an increase in the asymptotes during selection, while the age of the inflection point remained constant in all lines (21.3 to 26.0 d). For breast-muscle growth, ducks reached the inflection point 12.8 to 14.3 d later than for body weight. Between line A and line B, asymptotes for body weight, asymptotes for breast-muscle weight and allometric growth coefficients of breast muscle and leg and thigh muscles from 14 to 49 d were not significantly different. 5. The relative growth rate model discriminated body and breast-muscle growth patterns of line A and line B. The initial decline in the relative body growth rate was less and the time to reach the transition was longer in line A than line B. On the other hand, the initial decline in the relative breast-muscle growth rate was greater in line A than line B.

Stable lead isotope ratios from distinct anthropogenic sources in fish otoliths: a potential nursery ground stock marker.

Variations measured in the lead (Pb) stable isotope ratios in otoliths of juvenile tropical reef fish Scarus perspiculatus, Abudefduf abdominalis and Dascyllus albisella reflect mixing of anthropogenic lead from the Kaneohe Bay watershed and 'background' lead characteristic of the adjacent ocean. The otoliths and water samples collected in a transect across the bay demonstrated nearly identical Pb isotopic trends. The Pb isotopic composition of the watershed has a low 206Pb/204Pb signature primarily reflecting past combustion of tetra-ethyl Pb additive in fuels. Ocean water not contaminated by this watershed signature has a different, high 206Pb/204Pb isotopic composition, similar to previously measured Asian anthropogenic aerosols and natural eolian dusts, where the anthropogenic signal dominates. Where a history of past anthropogenic Pb contamination exists, it may be possible to use the ratios of Pb stable isotopes in fish otoliths to reconstruct the nursery grounds of fish.

Chemical preservation of whole broiler carcasses utilizing alkaline hydroxides.

The chemical preservation of whole broiler carcasses utilizing aqueous alkaline hydroxide solutions was examined as an alternative method of mortality management. Conversion of the preserved carcasses and solutions into an acceptable poultry by-product meal was examined. This research identified the basic parameters for effective preservative solutions that simultaneously hydrolyzed feathers and preserved the carcass. Euthanized, fully feathered, mature broilers were placed in potassium hydroxide (0.5 to 2.0 M) and sodium hydroxide (0.12 to 2.0 M) solutions for 5 and 10 d. Effectiveness was evaluated by visible feather degradation and carcass solubilization, odor production, inhibition of microbial growth, and solids content of the alkaline solutions. Sodium hydroxide at 1.9 and 2.0 M diffused throughout the carcass and produced adequate preservation without apparent putrefaction through 10 d. Aerobic bacteria were not recovered from sodium hydroxide solutions, carcass skin, or intestine samples at the 1.9 M concentration. Treatments of 2.0 M potassium hydroxide and a mixture of 1.5 M potassium hydroxide with 0.5 M sodium hydroxide produced the highest degree of carcass liquification at 10 d without visible putrefaction. Sodium hydroxide solution (2.0 M):carcass weight ratios ranging from 1:1 through 4:1 (wt:wt) were effective in preserving individual carcasses for more than 60 d without putrefaction.

Activation of soluble polysaccharides with 1-cyano-4-dimethylaminopyridinium tetrafluoroborate (CDAP) for use in protein-polysaccharide conjugate vaccines and immunological reagents. II. Selective crosslinking of proteins to CDAP-activated polysaccharides.

Covalently linking protein to polysaccharides converts the anti-polysaccharide immune response from a T-cell independent response to one which is T-cell dependent. The organic cyanylating reagent 1-cyano-4-dimethylaminopyridinium tetrafluoroborate (CDAP) (Vaccine 14:190, 1996) has been used to activate polysaccharides, which can then be reacted with spacer reagents or directly with protein. We wished to explore ways in which proteins could be linked to CDAP-activated polysaccharides to conjugate in a more controlled and selective fashion. To this end, we examined the reaction of nucleophilic amino acids with CDAP-activated polysaccharides under basic and acidic conditions. We found that lysine, cysteine and histidine but not methionine, serine or tyrosine conjugated to CDAP-activated dextran. We also examined the reaction of various spacer reagents with CDAP-activated dextran as a function of pH. The addition of hexanediamine was highly pH dependent and maximal at pH 9.3. In contrast, the addition of adipic dihydrazide, which has a pKa of ca 2.5 was essentially independent of pH. By performing the conjugation reaction at pH 5, we were able to selectively couple hydrazides even in the presence of high concentrations of amines. Proteins derivatized with limited numbers of hydrazides could be conjugated to CDAP-activated polysaccharides at pH5, where the native protein was not reactive. Proteins could be derivatized with hydrazides on carboxyls using adipic dihydrazide and a water soluble carbodiimide or on amines using a mild two-step reaction. Tetanus toxoid-pneumococcal type 14 conjugates produced by coupling hydrazide-derivatized tetanus toxoid under acidic conditions induced anti-polysaccharide antibodies at titers comparable to that stimulated by conjugates produced using a basic coupling pH. Our data suggest that crosslinking was occurring only with the limited number of hydrazides on the protein and that we achieved limited and selective crosslinking between the protein and CDAP-activated polysaccharide. This work also demonstrates that CDAP-mediated conjugation to polysaccharides can be applied even to very pH sensitive proteins and polysaccharides.

Gustatory function after third molar extraction.

OBJECTIVE: The purpose of this study was to determine the severity and time course of taste changes after extraction of all 4 third molars. STUDY DESIGN: Taste function in 17 patients was measured before third molar surgery and at 1 month and 6 months after surgery. Two tests were administered: a whole-mouth, above-threshold test in which subjects sipped, expectorated, and then rated the intensities and identified the taste qualities of various solutions, and a localized test in which subjects rated and identified solutions painted with cotton swabs on different oral sites. RESULTS: Intensity ratings for solutions in the whole-mouth test were reduced by approximately 14% for NaCl, citric acid, and quinine hydrochloride at 1 month after surgery and had not recovered by 6 months after surgery for citric acid (P<.02). The taste quality of NaCl was identified correctly less frequently after third molar extraction. Perceived taste intensity on discrete areas of the tongue was significantly reduced after surgery (P<.05). Patients with the most severely impacted molars gave the lowest taste intensity ratings to whole-mouth test solutions at 6 months after surgery (P<.02). In contrast, taste function in a group of subjects who received only local dental anesthesia was not affected. CONCLUSIONS: Gustatory deficits occur after third molar extraction, persist for as long as 6 months after surgery, and appear to be associated with depth of impaction.

The influence of cecectomy on metabolizable energy and amino acid digestibility of select feedstuffs for white Pekin ducks.

Twenty-four cecectomized and 24 intact White Pekin ducks were used in two experiments to assess the influence of cecectomy on ME and amino acid digestibility of several feed ingredients for ducks. Corn and soybean meal (SBM) were evaluated in Experiment 1, and bakery meal (BM), red dog (RD), and wheat middlings (WM) were evaluated in Experiment 2. Nitrogen-corrected true metabolizable energy and amino acid digestibility of the ingredients were assayed concurrently. In Experiment 1, TME of corn was higher (P < or = 0.05) in cecectomized ducks, and intact ducks demonstrated greater (P < or = 0.05) ability to utilize the energy in SBM. Intact ducks exhibited higher (P < or = 0.05) true digestibilities of lysine and methionine. True digestibility of tryptophan was higher (P < or = 0.05) for cecectomized ducks. True digestibility of indispensable amino acids in SBM did not differ (P > or = 0.05) between cecectomized and intact ducks. In Experiment 2, cecectomized ducks exhibited greater (P < or = 0.05) ability to utilize the energy in RD. Intact ducks exhibited greater (P < or = 0.05) ability to utilize the energy in WM. True digestibility of indispensable amino acids in BM, RD, and WM was variable. Results of the present study suggest that the effect of cecectomy on nutrient digestibility in ducks is dependent on the feedstuff assayed.

A dental fears typology of oral surgery patients: matching patients to anxiety interventions.

Two studies are described in which dental patients were administered the Dental Fear Survey (DFS) and then received 1 of 5 anxiety reduction interventions to prepare them for extraction of 3rd-molar teeth. Interventions included standard clinic treatment, oral premedication, and several relaxation-based procedures. Dependent variables were self-reported and observer-rated distress. In the 1st study (N = 231), cluster analyses of the DFS subscales revealed that patients could be subtyped as low-fear, high-fear, or cue-anxious patients who admitted fear only in response to specific stimuli. Dental fear subtypes were distinguishable by situational cognitions reported, and fear subtype interacted with anxiety intervention to predict distress. These results were replicated in the 2nd study (N = 150). The results are seen as supportive of a multidimensional view of dental anxiety.