Pharmacokinetics of tolfenamic acid after different administration routes in geese (Anser cygnoides).

The pharmacokinetics and bioavailability of tolfenamic acid were determined in geese (Anser cygnoides) following intravenous (IV), intramuscular (IM), subcutaneous (SC), and oral administrations at 2 mg/kg dose. In this study, eight healthy geese (3.5 ± 0.5 kg) were used. The study was performed in four periods according to a crossover design with a 15-day washout period between two administrations. The plasma concentrations of tolfenamic acid were analyzed using HPLC-UV, and pharmacokinetic parameters were calculated by noncompartmental analysis. The elimination half-life was 1.73, 2.51, 2.34, and 2.31 hr for IV, IM, SC, and oral routes, respectively. The volume of distribution at steady state and total clearance after IV administration were 0.25 L/kg and 0.16 L hr-1  kg-1 , respectively. The peak plasma concentrations of tolfenamic acid after IM, SC, and oral administrations were 4.89, 2.94, and 2.92 µg/ml at 0.25, 0.75, and 1 hr, respectively. The bioavailability was 87.91, 77.87, and 76.03% for the IM, SC, and oral routes, respectively. Tolfenamic acid, which exhibits the good bioavailability and plasma concentration following IM, SC, and oral administrations at 2 mg/kg dose, may be useful in the treatment of inflammatory disease conditions in geese.

Doxycycline pharmacokinetics in geese.

The study aims to describe the pharmacokinetics of doxycycline after a single intravenous and oral dose (20 mg/kg) in geese. In addition, two multiple-dose simulations have been performed to investigate the predicted plasma concentration after either a 10 or 20 mg/kg daily administration repeated consecutively for 5 days. Ten geese were enrolled in a two-phase cross-over study with a washout period of two weeks. All animals were treated intravenously and orally with doxycycline, and blood samples were collected up to 48 h after drug administration. Sample analysis was performed using a validated HPLC-UV method. A non-compartmental approach was used to evaluate the pharmacokinetic parameters of the drug. A long elimination half-life was observed (13 h). The area under the curve was statistically different between the two treatments, with the oral bioavailability being moderate (43%). The pharmacokinetic/pharmacodynamic index (%T>MIC) during the 48 h treatment period in the present study (71%) suggests that doxycycline appears to have therapeutic efficacy against some Mycoplasma species in the goose. The multiple-dose simulations showed a low accumulation index. A dosage of 10 mg/kg/day for 5 days seemed to be adequate for a good therapeutic efficacy without reaching unnecessarily high plasma concentrations.

Comparative Pharmacokinetics and bioavailability of marbofloxacin in geese (Anser Anser domesticus) after two sites of intramuscular administrations.

The pharmacokinetics of marbofloxacin (MAR) was compared in geese (Anser Anser domesticus) after single intravenous (IV) and intramuscular (IM) (thigh and pectoral muscles) administrations of 5 mg/kg. Serum concentrations of MAR were determined with high-performance liquid chromatography (HPLC) method. Serum MAR concentrations versus time were analyzed by a noncompartmental method. After IV administration, MAR showed high volume of distribution at steady state (Vdss ) of 5.24 ± 1.08 L/kg. The serum body clearance (Cl) and elimination half-life (T1/2 λz) of MAR were 0.79 ± 0.07 L hr-1  kg-1 and 6.94 ± 1.12 hr, respectively. The peak of MAR serum concentrations Cmax achieved at one and 0.50 hr after thigh and pectoral IM sites of injections, respectively, were 1.20 and 0.91 µg/ml. Significant differences were found in the mean absorption time (MAT), the systemic bioavailability (F%), and elimination parameters of MAR between two sites of injections, indicating that the absorption was fairly slow and complete after thigh IM injection. The pharmacokinetics of MAR in geese diverged according to the site of IM injection following a parallel study design. We recommend the thigh muscle as IM site of injection to obtain maximum concentrations of the administered drug in geese.

The effect of different dietary levels of sodium and chloride on performance and blood parameters in goslings (1-28 days of age).

A total of 702 1-day-old male Jiangnan White goslings were used to study the effects of varying levels of Na+ and Cl- on their growth performance and blood parameters. In this experiment, goslings were randomly allotted to nine treatments, with six pens per treatment in a 3 × 3 factorial arrangement, and fed diets with three concentrations of added Na+ (0.10%, 0.15% and 0.20%) and three concentrations of added Cl- (0.15%, 0.20% and 0.25%). The purpose of this experiment was to investigate the sensitivity of goslings to Na+ and Cl- during brooding to determine the appropriate levels of Na+ and Cl- in their feed. The results are as follows: (a) Different levels of Na+ and Cl- in the diet, especially low Na+ and Cl- , significantly affected the body weight (BW), average daily gain (ADG) and feed/gain ratio (F/G) of the 28-day-old goslings (p < .05). But Na+  × Cl- has no significant effect on water consumption (p > .05). (b) Serum concentrations of urea increased linearly with Na+ content (p < .05). Serum concentrations of creatinine (CR) and uric acid (UA) increased linearly with Cl- content (p < .05). (c) Na+  × Cl- has a significant impact on the serum sodium (Na) and chlorine (Cl; p < .05). The content of serum Na and Cl increased linearly with increasing levels of Na+ and Cl- . These results show that low levels of Na+ and Cl- had significant adverse effects on the growth of 1- to 28-day-old goslings. The results of the experiment support a recommendation to supplement the diet of goslings with 0.20% Cl- and not <0.15% Na+ .

Effect of dietary Moringa stem meal level on growth performance, slaughter performance and serum biochemical parameters in geese.

Moringa stem meal (MSM) with a high level of crude fibre (CF) might be developed and utilized in herbivorous geese as an unconventional feedstuff. The aim of this study was to investigate the effect of the MSM level in the diet on the growth performance, slaughter performance, breast meat quality and serum biochemical parameters in geese from 22 to 70 days of age. A one-factor completely randomized design was adopted in our study. A total of one thousand eight 21-day-old geese were randomly divided into six groups, with six replicates per group and 28 birds per replicate. The geese were fed diets containing MSM levels of 0, 20, 40, 60, 80 or 100 g/kg during day 22-70. The dietary MSM level had no effect (p > .05) on the final body weight (BW), average daily gain (ADG) or average daily feed intake (ADFI). The feed/gain ratio (F/G) increased linearly (p < .001) as the dietary MSM level increased. No differences (p > .05) were observed in the slaughter performance, meat quality and the relative organ weight (except for thymus) of the geese (p > .05). The relative weight of the thymus in the geese fed diets with supplementation of MSM was higher than that in the non-supplemented MSM control group (p < .05). In addition, 100 g MSM/kg of diet decreased the serum glucose (GLU) level (p < .05) and increased the alanine transaminase (ALT) enzyme activity (p = .03). Dietary MSM levels of no more than 60 g/kg had no effects on the growth performance and slaughter performance, whereas diets with 100 g MSM/kg increased the F/G and serum ALT enzyme activity, as well as decreasing the serum GLU level. Therefore, MSM provided at a reasonable level could be developed as an unconventional feedstuff for geese at the finisher period.

Type C/D botulism in the waterfowl in an urban park in Italy.

This report describes an outbreak of botulism occurred among a free-living population of mallards (Anas platyrhynchos) and geese (Anser anser) in an urban park. Mortality rate among investigated population was 86,8% (118 dead out of 136). Twenty-seven carcasses were collected for macroscopic examination and screened for microbiological, virological, toxicological investigations. A sick mallard was captured and neurological symptoms were observed. No causative agent of viral avian diseases was found in the examined animals and screening for environmental neurotoxic substances proved negative as well. In contrast, microbiological cultures from specimens tested positive for botulinum toxin-producing clostridia. Blood serum and fecal extract of the sick mallard proved positive for botulinum neurotoxin in the standard mouse protection test using reference Clostridium botulinum type C antitoxin. Gene content of cultured strains showed a mosaic composition of bont/C and bont/D sequences, defining them as type C/D chimeric organisms.

Effect of photoperiod on serum hormone concentrations during the annual reproductive cycle in geese.

The poor egg-laying rate of geese hinders the development of the goose industry; therefore, the reproductive performance of geese is an important area of investigation. To evaluate the relationship between photoperiod, reproductive hormones, and reproductive activity during the egg-laying cycle in geese under natural conditions, we collected blood samples from Sichuan white geese and Xupu geese to quantify changes in prolactin (PRL), estradiol (E2), vasoactive intestinal polypeptide (VIP), follicle stimulating hormone (FSH), gonadotropin-inhibitory hormone (GnIH), and luteinizing hormone (LH). We also calculated the rate of egg laying for the two populations during the egg-laying cycle. We show that the egg-laying rate and the serum concentration of some hormones (PRL, E2, VIP, FSH, GnIH, and LH) differed significantly between the two populations during the pre-laying, laying, and ceased-laying periods. Serum LH concentrations may be associated with maturation of the ovary and oviducts, whereas FSH, PRL, and GnIH play important roles in egg laying. These results provide a useful resource for future studies examining the laying rate in geese.

Fuel metabolism in Canada geese: effects of glucagon on glucose kinetics.

During prolonged fasting, birds must rely on glucose mobilization to maintain normoglycemia. Glucagon is known to modulate avian energy metabolism during prolonged fasting, but the metabolic effects of this hormone on long-distance migrant birds have never been investigated. Our goal was to determine whether glucagon regulates the mobilization of the main lipid and carbohydrate fuels in migrant birds. Using the Canada goose (Branta canadensis) as a model species, we looked for evidence of fuel mobilization via changes in metabolite concentrations. No changes could be found for any lipid fraction, but glucagon elicited a strong increase in glucose concentration. Therefore, we aimed to quantify the effects of this hormone on glucose kinetics using continuous infusion of 6-[(3)H]-d-glucose. Glucagon was found to cause a 50% increase in glucose mobilization (from 22.2 ± 2.4 µmol·kg(-1)·min(-1) to 33.5 ± 3.3 µmol·kg(-1)·min(-1)) and, together with an unchanged rate of carbohydrate oxidation, led to a 90% increase in plasma glucose concentration. This hormone also led to a twofold increase in plasma lactate concentration. No changes in plasma lipid concentration or composition were observed. This study is the first to demonstrate how glucagon modulates glucose kinetics in a long-distance migrant bird and to quantify its rates of glucose mobilization.

Characterization of HSP70 and its expression in tissue: correlation with physiological and immune indices in goose (Anser cygnoides) serum.

We cloned the goose heat shock protein 70 gene (HSP70), to determine its sequence variation and elucidate its mRNA expression. We designed primers to amplify the entire goose HSP70 sequence. We used 10 commercial Wuzong goslings in a heat-stress experiment. We collected tissue samples for RNA extraction and quantitative real-time polymerase chain reaction (qRT-PCR). We analyzed the variation in expression of goose HSP70 before and after heat stress. We constructed a DNA pool from six different species, for single nucleotide polymorphism (SNP) screening. We detected 18 SNPs and selected three of these SNPs for correlation analysis with biological and immune traits in 200 Wuzong geese. We showed that T+237C was significantly correlated with the serum corticosterone level, whereas T+1122C was significantly correlated with the heterophil to lymphocyte ratio. Goose HSP70 contained no introns. The results of qRT-PCR analysis revealed significant gender differences in the expression of goose HSP70 at 40°C but not at 25°C; moreover, in general, expression was significantly higher at 40°C than at 25°C. With the exception of the leg muscle and cerebellum, HSP70 expression was significantly higher in male geese than in female geese. Our results indicate that goose HSP70 plays an important role in response to severe heat stress.

Meat quality, oxidative stability and blood parameters from Graylag geese offered alternative fiber sources in growing period.

The effects of dietary fiber sources on the meat quality, oxidative stability, and blood parameters of growing Graylag geese (28-112d) were investigated. The birds were randomly allocated into 4 treatments, of which dietary fiber was mainly from corn straw silage (CSS), steam-exploded corn straw (SECS), steam-exploded wheat straw (SEWS), and steam-exploded rice straw (SERS). No influence (P>0.05) on the basic chemical components, oxidative stability, or organoleptic traits of muscle were observed, except that birds fed SECS had a higher (P<0.05) protein proportion than those fed CSS or SERS, and CSS increased (P<0.01) the cholesterol content when compared to SEWS or SERS. Regarding fatty acid profile in meat, CSS and SECS increased (P<0.01) the proportion of C18:2n6t and decreased that of C21:0 and C22:0 when compared to the others. The birds fed SERS had a higher (P<0.05) proportion of C20:0 and C22:0 than the others, a higher proportion of C20:5n3, n-3 fatty acids, Δ-9 desaturase (18) index compared to those fed CSS or SECS, and a lower (P<0.01) proportion of C20:1n9 than those fed SECS or SEWS. Additionally, SEWS resulted in a higher (P<0.01) proportion of C20:2 when compared to the others. In conclusion, these fibers affect just the protein proportion, cholesterol content, and fatty acid profile of breast muscle, along with the concentration of TG and MDA in blood, but not the other characteristics. No superior fiber source exists with respect to meat quality, suggesting that Graylag geese feeding should make the most economically of the convenient fiber source with appropriate pretreatment.

Strains of the intestinal spirochaete Brachyspira pilosicoli attach to and aggregate erythrocytes.

UNLABELLED: The anaerobic intestinal spirochaete Brachyspira pilosicoli colonizes the large intestine of various species of mammals and birds, where it may induce colitis. Strains of the spirochaete have also been isolated from the bloodstream of immunocompromised human patients and have been seen in liver sections, and a similar systemic spread was recently observed in experimentally infected chickens. Some other spirochaete species that may be present in blood attach to and aggregate erythrocytes, and this is believed to contribute to disease severity. The aim of the current study was to determine whether B. pilosicoli strains have the capacity to attach to and aggregate erythrocytes. Initially, four strains of B. pilosicoli were incubated with erythrocytes from sheep, cows, pigs, dogs, humans, chickens and geese, and were observed by phase-contrast microscopy. Only strain WesB attached, and this was only with erythrocytes from chickens and geese. Subsequently, six other strains of B. pilosicoli were tested just with goose erythrocytes, and five attached to and caused aggregation of the erythrocytes. Scanning and transmission electron microscopy demonstrated that spirochaetes abutted and apparently firmly attached to the erythrocyte membranes. Aggregation of erythrocytes by B. pilosicoli may contribute to disease severity in species that develop a spirochaetaemia. SIGNIFICANCE AND IMPACT OF THE STUDY: The intestinal spirochaete Brachyspira pilosicoli has been isolated from the bloodstream of immunocompromised human patients, and spread to the liver has been reported in humans and in experimentally infected chickens. In this study, B. pilosicoli was shown to undergo attachment by one cell end to chicken and goose erythrocytes in vitro and to aggregate them. This activity has the potential to contribute to disease severity in avian and possibly other species that develop a spirochaetaemia and systemic spread. Avian erythrocytes may be useful for studying the mechanisms by which B. pilosicoli attaches to cells.

Effects of feed conditioning temperature on pellet quality, growth performance, intestinal development and blood parameters of geese from 1 to 28 d of age.

A 28-d experiment was conducted to investigate the effects of feed-conditioning temperature on the pellet quality, growth performance, intestinal development, and blood parameters of geese. A total of 180 one-day-old White Yuzhou goslings were randomly allotted to 5 treatment groups, with 6 replicates containing 6 birds each. Five diets were conditioned at 65, 70, 75, 80, and 85°C. Body weight and feed intake per pen basis were recorded from the arrival to the end of the trial. Blood and small intestine samples were collected on d 28 for analysis. The results showed that the pellet durability index (PDI), pellet hardness, and gelatinisation degree of starch (GDS) increased with increasing conditioning temperature (P < 0.05). The final body weight (FBW), average daily gain (ADG) and average daily feed intake (ADFI) of goslings significantly increased when conditioning temperature increased from 65 or 70°C to 80 or 85°C (P < 0.05), accompanied by unaffected feed conversion ratio (FCR) (P > 0.05). The villus height to crypt depth ratio (VH/CD) in the duodenum and ileum improved with increasing conditioning temperature (P < 0.05). Additionally, trypsin and amylase activity were enhanced when the conditioning temperature increased from 65 to 85°C (P < 0.05). No significant differences in the carcass traits and blood parameters of goslings were observed among the groups (P > 0.05). Overall, under the present experimental conditions, increasing the steam-conditioning temperature of pelleted feed improved pellet quality, growth performance, intestinal morphology, and digestive enzyme activity in goslings. Based on broken-line regression analysis, the lower critical conditioning temperature for ADG in geese from 1 to 28 d of age was 80.95°C.

Research Note: Development of a sandwich ELISA for determining plasma growth hormone concentrations in goose.

Growth hormone (GH) is required for normal postnatal development in poultry; however, no immunoassay exists to assess its levels in geese plasma, hindering the study of endocrine regulation in this species. We developed a sandwich ELISA to determine the GH concentrations in the plasma of geese. Recombinant goose GH was produced using a eukaryotic expression system and purified for use as the reference standard in ELISA and the antigen for producing the polyclonal antibodies in rabbits. Rabbit anti-goose GH polyclonal antibody was used to coat the wells of the ELISA plate, and its biotinylated form served as the detection antibody. An avidin-conjugated horseradish peroxidase was used to bind the detection antibody and catalyze the chromogenic reaction of 3,3,5,5-tetramethylbenzidine and H2O2. A sigmoidal curve was fitted to the optical density and the log of the standard GH concentration using the four-parameter logistic model. The sensitivity of the assay was less than 0.156 ng/mL. The intra- and interassay coefficients of variation were less than 9 and 13%, respectively. The response curve of the serially diluted plasma samples from geese exhibited a good parallel relationship with that observed for the reference standards. The assay effectively detected differences in GH concentrations in plasma samples from geese at various physiological stages; thus, it will be useful for future study of their growth and metabolism.

Variations in leucocyte profiles and plasma biochemistry are related to different aspects of parental investment in male and female Upland geese Chloephaga picta leucoptera.

The analysis of plasma biochemistry and haematology to monitor the condition of birds in the wild has been found a useful tool in ecological research. Despite biparental investment in most wild birds studied, some studies of condition indices found sex differences, and attributed these to the costs of egg formation or brooding in females or a higher contribution of males to chick rearing. We studied the natural variation of haematological and plasma biochemistry parameters (namely leucocyte, lymphocyte and heterophil counts, H/L ratio and plasma concentrations of proteins, triglycerides and carotenoids) in relation to the different measures of parental investment in males and females in the Upland goose (Chloephaga picta leucoptera), a socially monogamous species. We found no sex differences in haematological and most plasma biochemistry parameters, but a relation to different aspects of parental investment in breeding male and female Upland geese. H/L ratios were related to body condition and capture date in males while leucocyte counts, plasma protein and plasma carotenoid concentrations varied with clutch measures and hatching date in females. Higher H/L ratios of males in a low body condition and later in the year may reflect stress associated with the investment into the establishment and defence of the breeding territory. Females with higher clutch volumes had lower total leucocyte and lymphocyte numbers and higher levels of plasma protein. Earlier hatching dates were associated with lower numbers of all leucocyte types and higher values of plasma carotenoid concentrations. This indicates that differences in health state are reflected in reproductive performance in female Upland geese. We also found sexual differences in the repeatability of haematological and plasma biochemistry parameters between years and therefore suggest that their potential as a measure of individual quality differs between male and female Upland geese. Finally, numbers of leucocyte counts and plasma triglyceride concentrations of pair partners were significantly related. No study so far investigated these parameters in pair partners and we discuss possible reasons for our finding.

High fliers: the physiology of bar-headed geese.

Up to half the world's population of bar-headed geese (Anser indicus) migrate between central Asia and India and fly between 5000 m and 9000 m above sea level as they cross the Himalayas. The partial pressures of oxygen at these altitudes are, respectively, about 50% and 30% those at sea level. Flapping flight is energetically expensive, so how are bar-headed geese able to migrate at such altitudes? The haemoglobin of bar-headed geese has a greater affinity for oxygen than those of lowland birds, and birds are able to hyperventilate to a greater extent than mammals during severe hypoxia. Together, these mean that the concentration of oxygen in the arterial blood at a given altitude is greater in bar-headed geese than in lowland birds and mammals. The low partial pressure of CO(2) in arterial blood (hypocapnia) that accompanies hyperventilation does not cause reduction of cerebral blood flow in birds as it does in mammals, thus there is greater oxygen delivery to the brain in hypoxic birds, including bar-headed geese, than in mammals. Captive bar headed geese could not maintain elevated aerobic metabolism during exercise at a simulated altitude of 8500 m and their cardiac stroke volume was much lower than that during exercise at sea level. This suggests that if some individuals of this species of geese do really manage to fly over Mt Everest, they may only do so if they receive assistance from vertical air movements, for example from lee waves downwind from the mountains.

Effect of nanoliposomal entrapment on antioxidative hydrolysates from goose blood protein.

In this study, the encapsulation of goose blood hydrolysate (GBH) was performed within nanoliposomes. We investigated the physicochemical properties, stability, antioxidant indices, the morphology of nanoparticles, the digestion stability in simulated gastrointestinal fluid, differential scanning calorimetry (DSC) analysis, and Fourier transform infrared (FTIR) spectroscopy. GBH was successfully encapsulated into nanoliposomes using reverse-phase evaporation method. The entrapment efficiency of GBH-loaded nanoliposomes was about 70.99 ± 2.85%, the average particle size was 93.3 ± 2.45 nm, the zeta-potential of GBH-loaded nanoliposomes was -30 mV, and the morphology of GBH-loaded nanoliposomes was characterized by transmission electron microscope. Moreover, the results of DSC and FTIR showed that the GBH nanoliposome was more stable than the empty liposomes due to hydrogen bond complexation between liposome and GBH. The release of GBH from nanoliposomes could be significantly controlled, and the release ratios were 48.9 ± 2.96% in simulated gastric fluid and 59.9 ± 5.30% in simulated intestinal fluid, respectively, proving that degradation rate of antioxidant activities of GBH encapsulated in nanoliposomes was decreased. In conclusion, nanoliposomes embedding is a promising and effective way to increase the stability of hydrolysates from GBH and produce various types of functional food.

Dietary combined supplementation of iron and Bacillus subtilis enhances reproductive performance, eggshell quality, nutrient digestibility, antioxidant capacity, and hematopoietic function in breeder geese.

A 3 × 2 factorial arrangement of treatments was conducted to investigate the effects of iron (Fe, 40, 60, and 80 mg/kg) and Bacillus subtilis (2.5 × 109 and 5.0 × 109 CFU/kg) supplementation on reproductive performance, egg quality, nutrient digestibility, hormone levels, antioxidant indices, and hematological parameters in breeder geese. A total of one hundredtwenty 46-week-old Wulong breeder geese were randomly assigned to 1 of 6 dietary treatments with 4 replicates per treatment and 5 geese per replicate for 10 wk following 1 wk of adaption. Dietary Fe supplementation increased egg weight (P = 0.036), fertility (P = 0.022), serum total antioxidant capacity (P = 0.022), red blood cell (P = 0.001), hematocrit (HCT, P < 0.001), hemoglobin (HGB, P = 0.005), and mean corpuscular volume (MCV, P < 0.001). Dietary B. subtilis supplementation increased egg production (P = 0.025), eggshell thickness (P = 0.020), apparent phosphorus digestibility (P < 0.001), serum follicle stimulating hormone (P = 0.043), total antioxidant capacity (P < 0.001), HCT (P < 0.001), HGB (P < 0.001), and MCV (P = 0.025), and reduced malondialdehyde level (P = 0.008). The birds fed diets supplemented with 60 mg/kg Fe and 5 × 109 CFU/kg B. subtilis showed the highest percentage of hatched eggs (P = 0.004) and mean corpuscular hemoglobin (P < 0.001) among the 6 groups. Supplementation of 40 and 60 mg/kg Fe significantly increased the apparent digestibility of calcium compared with that of 80 mg/kg Fe in the birds fed 5.0 × 109 CFU/kg B. subtilis (P = 0.004). Supplementation with 60 and 80 mg/kg Fe in the birds fed 5 × 109 CFU/kg B. subtilis significantly decreased serum urea nitrogen level compared with other 4 groups (P = 0.022). In conclusion, the combination of Fe and B. subtilis effectively improves reproductive performance, eggshell quality, nutrient digestibility, antioxidant status, and hematopoietic function of breeder geese. Dietary addition of 60 mg/kg Fe and 5.0 × 109 CFU/kg B. subtilis was an optimum supplementation dose.

Amino acid sequence homology between histone H5 and murine leukemia virus phosphoprotein p12.

The amino terminal acid sequences of several mouse leukemia virus phosphoproteins (p12) show definite homology with the amino terminal conserved region of H5 histones, the phosphorylated nuclear proteins of nucleated erythrocytes. Differences in the amino acid compositions of the two groups of proteins seem to rule out the possibility that they evolved from a single common ancestral gene. The finding of sequence homology between viral p12's and cellular histones, however, is consistent with evolution of retrovirus structural proteins by a process of differentiation from preexisting cellular genes. The conserved primary and secondary structure at the amino terminal region, common to both groups of proteins, may be related to their common function of nucleic acid binding modulated by phosphorylation.

Influence of molt on plasma protein electrophoretic patterns in bar-headed geese (Anser indicus).

Plasma protein electrophoresis is recognized as a reliable diagnostic tool in avian medicine; however, the influence of circannual phenomena such as molt on protein electrophoregrams is poorly documented. The molt is a period of heavy hormonal and metabolic change in birds. The purpose of this study was to investigate the effects of molt on total protein concentration and electrophoresis patterns in birds. Blood samples were taken from 19 Bar-headed Geese (Anser indicus) from mid-May to mid-August, at 15-day intervals. At the same time, molting stage of each bird was recorded. Total protein concentrations were measured and plasma agarose gel electrophoresis was performed on these samples. The Bar-headed Goose was chosen as a model, because they molt over a very short period. The total protein concentration and albumin, alpha-2, beta, and gamma fractions were at their minimum values during molt, whereas the prealbumin and alpha-1 fractions rose to their maximum levels. This study provides baseline information relevant to changes occurring in avian proteinograms throughout the molt. The increase in prealbumin and alpha-1 fractions may be related to an increase in plasma thyroid hormones during molt. The decrease observed in albumin, alpha-2, beta, and gamma fractions may be related to protein and energy shifts toward feather growth, as well as to an expansion of the circulatory system located around the feather follicles with secondary dilutional effects on protein fractions. From a clinical point of view, the observed changes associated with molting were less significant than initially expected, and would not likely results in incorrect diagnoses based on interpretation of the protein electrophoretic patterns.

Plasma biochemistry values in emperor geese (Chen canagica) in Alaska: comparisons among age, sex, incubation, and molt.

Reduced populations of emperor geese (Chen canagica), a Bering Sea endemic, provided the need to assess plasma biochemistry values as indicators of population health. A precursory step to such an investigation was to evaluate patterns of variability in plasma biochemistry values among age, sex, and reproductive period. Plasma from 63 emperor geese was collected on their breeding grounds on the Yukon-Kuskokwim Delta in western Alaska, USA. The geese sampled included 18 incubating adult females captured, in mid June, on their nests by using bow nets, and 30 adults and 15 goslings captured in corral traps in late July and early August, when the adults were molting their wing feathers and the goslings were 5-6 weeks old. Plasma was evaluated for 15 biochemical parameters, by comparing results among age, sex, and sampling period (incubation versus wing-feather molt). Ten of the 15 biochemical parameters assayed differed among adults during incubation, the adults during molt, and the goslings at molt, whereas sex differences were noted in few parameters.