Effects of dietary chitosan on growth rate,small intestinal morphology,nutrients apparent utilization and digestive enzyme activities of growing Huoyan geese

Dietary chitosan (CS) supplementation could improve the growth rate, small intestinal morphology, nutrients apparent digestibility and digestive enzyme activities in pigs, broiler chickens, rats and fish, whereas no data has been reported about the effect of CS on the growing Huoyan geese. Therefore, this study was designed to investigate the effects of CS on growth rate, small intestinal morphology, nutrients apparent utilization and digestive enzyme activities of growing Huoyan geese. Three hundred and twenty (28 days of age, gender balance) Huoyan geese were randomly divided into control, CS₁₀₀, CS₂₀₀ and CS₄₀₀ groups (based on BW) with 20 geese per pen and 4 replicates pen per group, and the feeding experiment lasted for 4 weeks. The 4 diets contained 0, 100, 200 and 400 mg CS per kg feed, respectively. The results showed that CS₂₀₀ groups had higher average daily gain, final BW, apparent utilization of DM and CP, and lower feed/gain ratio compared with the control group (P < 0.05). Meanwhile, CS₁₀₀ and CS₂₀₀ groups had higher villus height, villus height/crypt depth ratio and lower crypt depth in duodenum and jejunum than those in the control group (P < 0.05). The geese in CS₁₀₀ and CS₂₀₀ groups had higher villus height, villus height/crypt depth ratio and lower crypt depth of ileum compared with those in control and CS₄₀₀ groups (P < 0.05). In addition, compared with the control group, CS₂₀₀ group has higher trypsin activities and lower lipase activities in duodenal, jejunal and ileal contents (P < 0.05). The results suggested that addition of 200 mg/kg CS had positive effects on growth rate, small intestinal morphology, nutrients apparent utilization and digestive enzyme activities of growing Huoyan geese.     

Determination of bean nodule occupancy by <Emphasis Type="Italic">Rhizobium tropici</Emphasis> using the double <Emphasis Type="Italic">gfp</Emphasis> and <Emphasis Type="Italic">gusA</Emphasis> genetic markers constitutively expressed from a new broad-host-range vector

A new broad-host-range vector expressing constitutively the reporter genes gfp and gusA was used to evaluate nodule occupancy of Phaseolus vulgaris nodules by Rhizobium tropici. The results showed that the pHRGFPGUS plasmid was stably maintained in R. tropici over 45 generations and can therefore be used in nodule competitiveness assays. A new method for determining the nodule occupancy using the green fluorescent protein as a marker is described and is shown to be quick, inexpensive and reliable.     

改良的硫酸铵沉淀法纯化大雁的卵黄抗体

目的 探索有效的纯化大雁卵黄抗体及高效价二抗的方法。方法 应用了PEG沉淀,阴离子交换柱,硫酸铵分级沉淀纯化,免疫制备二抗,免疫电泳和免疫双扩散法及western blotting进行效价的测定。结果 改良后的硫酸铵沉淀法的纯度远远高于PEG沉淀,相对于离子交换法而言更加简单方便,经济省时。从免疫电泳看已达到了电泳纯,大雁卵黄IgY的相对分子质量为180×10^3,重链约为66×10^3,轻链约为24×103。免疫获得的二抗有较强的免疫活性。结论 用改良的硫酸铵沉淀法纯化大雁卵黄抗体,效率和纯度显著提高,值得推广。本实验为大雁卵黄抗体及其二抗的应用奠定了基础,也为雁形目其他种类卵黄抗体的纯化提供了参考。     

Occurrence of Polysiphonia Epiphytes in Kappaphycus Farms at Calaguas Is., Camarines Norte, Phillippines

This paper describes the occurrence of an epiphyte infestation of Kappaphycus farms in Calaguas Is. Camarines Norte, Philippines. In particular, percentage cover of ‘goose bump’-Polysiphonia and ‘ice-ice’ disease, and some environmental parameters that influence the thallus condition of Kappaphycus alvarezii in Calaguas Is. were assessed during 3 separate visits and are discussed.Commercial cultivation of Kappaphycus at Calaguas Is. began in the early 1990s. After five years of farming, the stock was destroyed by a strong typhoon. The area was re-planted the following year and production increased annually and reached its peak in 1998–1999. However, the following year, the first occurrence of a Polysiphonia epiphyte infestation occurred concurrently with an ‘ice-ice’ disease. Consequently, annual production and the number of seaweed planters declined rapidly, and this situation persists to the present time. This paper highlights the etiological factors and their consequences.Results show that farm-site selection is critical for the success of Kappaphycus production. Characteristics of water movement and light intensity in farming areas contributed to the occurrence and detrimental effect of the phenomenon described as ‘goose bumps’: a morphological distortion of the host seaweed due to the presence of a Polysiphonia sp. epiphyte. A strong inverse correlation was observed between the occurrence of Polysiphonia and water movement: areas with low water motion registered a higher % cover (65%) of Polysiphonia than those in more exposed areas (17%). Although ‘goose bump’-Polysiphonia infestation and ‘ice-ice’ disease pose a tremendous problem to the seaweed farmers, the results of this limited assessment provide a useful baseline for future work.     

A fluorescent PCR assay for the codominant interpretation of a dominant SCAR marker linked to the virus resistance allele bc-1 2 in common bean

Our objective was to develop a rapid and accurate procedure to genotype common bean plants for the bc-1 ² allele, which conditions resistance to bean common mosaic and bean common mosaic necrosis viruses. A segregating F₂ population was derived from the cross between pinto bean breeding lines P94207-43 (bc-1 ²//bc-1 ²) and P94207-189 (bc-1//bc-1). A quantitative PCR assay based on the detection of fluorescent labeled amplicons was developed to distinguish between homozygous (bc-1 ²//bc-1 ²), heterozygous (bc-1 ²//bc-1) and null (bc-1//bc-1) F₂ genotypes. Remnant F₁ plants were used as a comparative reference sample. PCR results among this sample fit a normal distribution, and 99% and 95% confidence intervals for heterozygotes were determined. F₂ plants for which no amplification was detected were classified as null (bc-1//bc-1) genotypes. F₂ plants that fell within the confidence intervals for heterozygotes were classified as heterozygotes (bc-1 ²//bc-1), while plants that fell outside the right tail of the heterozygote confidence intervals were classified as homozygotes (bc-1 ²//bc-1 ²). F₂ plants were also genotyped for the bc-1 ² allele by performing F₃ family progeny tests for virus resistance. Agreement between the two methods for genotyping plants was 100% (59/59) when PCR genotyping was based on a 99% heterozygote confidence interval, and 98.3% (58/59) when based on a 95% heterozygote confidence interval. This assay will accelerate breeding for virus resistance in bean by facilitating discrimination among plants that are heterozygous or homozygous for the bc-1 ² allele. The experimental design may be generally applicable towards developing other assays for the codominant interpretation of dominant markers in diploid plants.     

Ph?nologie und Raumnutzung von Bl?ssg?nsen (Anser albifrons) benachbarter Teilpopulationen am Unteren Niederrhein

Zusammenfassung Die vorliegende Untersuchung stellt Daten zur Phänologie und Raumnutzung der Blässgans in einem knapp 120 km² großen Untersuchungsgebiet am Unteren Niederrhein vor. Mooij (1993) unterschied im deutschen Teil der Überwinterungsregion fünf als Schlafkomplexe definierte Teilpopulationen. Diese nutzen Nahrungsräume über deren Überlappung noch keine Erkenntnisse vorliegen. Das Untersuchungsgebiet der vorliegenden Arbeit beinhaltet überwiegende Teile der linksrheinischen Nahrungsräume der beiden westlichsten dieser Teilpopulationen. Um die Überlappung der Nahrungsräume aufzuzeigen wird die Phänologie des Gesamtgebiets sowie getrennt für den Ost- und Westteil, den Nahrungsräumen der benachbarten Schlafkomplexe, beschrieben. Die ökologische Funktion des Rheinvor- und Hinterlandes, das sich im Anteil der nach NSG-Verordnung geschützten Bereiche stark unterscheidet, wurde ermittelt, indem die räumliche Verteilung der Gänse auf diese Bereiche für Sextadenintervalle bestimmt wurde. Der Beweidungsdruck auf das Vorland sowie das Nutzungsmuster ausgewählter Grünlandgebiete im Vorund Hinterland lieferte Informationen über den Einfluss abiotischer Faktoren auf die Nutzungsintensität und Tragkraft dieser Teilbereiche. Die Ergebnisse zeigen: (1) Die Gänsezahl stieg während der ersten Novemberhälfte auf ca. 20.000 an. Wintermaxima traten mit ca. 51.000 1997/98 und ca. 57.000 Individuen 1998/99 Ende Dezember auf. Im Spätwinter setzte abhängig von den Witterungsbedingungen allmählicher Abzug ein. (2) Fluktuationen der Bestandsgröße eines Nahrungsraums traten häufig mit entgegengesetzten Schwankungen im benachbarten Gebiet auf und können, wie im Einzelfall dokumentiert, mit einem Schlafplatzwechsel gekoppelt sein. (3) Die anteilige Nutzung des Rheinvorbzw. Hinterlandes lag 1997/98 bei ca. 42:58 und 1998/99 bei 27,5:72,5 Prozent. Im Jahresverlauf schwankte sie periodisch. (4) Die Gesamtbeweidung des Vorlandes war 1998/99 trotz größerer Population und längerer Rastperiode um 24 Prozent geringer als 1997/98. Dies lässt auf eine durch Temperatur- und Überschwemmungseinflüsse reduzierte Tragkraft schließen. (5) Ausgewählte Rheinvor- und Hinterlandgebiete kennzeichnet ein periodisches Nutzungsmuster. Dies wurde durch Hochwasser- und Temperaturverlauf wie folgt beeinflußt: Im Vorlandgebiet waren Besuchsfrequenz und mittlere Verbandsgröße im milden Winter 1997/98 besonders hoch, im strengen Winter 1996/97 und nach längerer Überflutung 1998/99 aber deutlich herabgesetzt. Im Hinterlandgebiet war die Besuchsfrequenz und mittlere Verbandsgröße im milden Winter 1997/98 am geringsten und 1998/99 bei ebenfalls relativ mildem Klima, aber durch Hochwassereinflüsse verminderter Tragkraft des Vorlandes, am höchsten. Der strenge Winter 1996/97 nahm eine Mittelstellung ein.

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Phenology and spatial distribution of White-fronted Geese (Anser albifrons) wintering in neighbouring roost sites on the Lower Rhine

Summary Based on frequent goose counts, data are presented on abundance and spatial distribution of White-fronted Geese wintering in the north-western part of the Lower Rhine area, North Rhine Westfalia, FRG, in an area of about 117 km². In accordance to the main roost sites in the lower Rhine valley, Mooij (1993) divided the wintering population into five subpopulations, called roost complexes, and put forward a definition of their foraging areas. No information on the degree of separation of these subpopulations or on overlapping of their foraging areas has so far been available. The study area of this investigation includes neighbouring foraging areas of the two western roost complexes in the German part of the Lower Rhine region. Based on frequent goose counting (two-days counts in 1997/98, almost daily counts in 1998/99) the abundance-phenology is described for the study area both as a whole and split up into eastern and western parts (B220-East, B220-west) corresponding to the two different roost-complexes. In this way it is possible to obtain informations on the overlap of foraging areas, which indicates regular goose movements between the subpopulations.To get information on the ecological function of mainly protected foreshore areas, defined as areas located riversides of the dike, and mainly unprotected polder areas outside of the dike, the spatial distributions of geese on these parts of the study area were determined for six-day intervals. The comparison of grazing activity on foreshore areas, counted almost daily in 1997/98 and 1998/99, afforded information about carrying capacity in relation to wintering conditions. In selected preferred foreshore and polder areas, counted almost daily since 1996/97, grazing patterns were used to analyze the impact of temperature and flooding periods on the carrying capacity and the spatial distribution of geese. Our data show: (1) Numbers of geese increased during the first half of November from a few hundred up to 20,000 birds. Winter maxima were reached in the last 10-day period of December with 51,000 birds in 1997/98 and 57,000 in 1998/99. The gradual departure of geese from the beginning of February depended on weather conditions. (2) The average number of geese was higher in the western part of the study area and the exploitation of the area started earlier than in the eastern part. (3) Fluctuations in goose numbers in both eastern or western parts of the study area were often related to complementary fluctuations in goose number in the neighbouring part of the study area, which is an indication of the overlap of the foraging areas. In one individual case it was possible, by following a great number of geese, to verify that complementary fluctuations could be connected with a change in roost sites. (4) The proportion of goose days spent on foreshore and polder areas was 42.4vs. 57.6% in 1997/98 and 27.5vs. 72.5% in 1998/99. (5) During the wintering periods the proportion of goose days showed periodical fluctuations, i.e., after a few days with large numbers of grazing geese on foreshore areas, there were weeks with very small goose numbers. (6) In spite of the larger population size and longer wintering period, in the colder winter with floodings of 1998/99 the absolute amount of grazing on foreshore areas was 24% less than in the warmer winter without floodings of 1997/98. This leads to the conclusion that the carrying capacity had been reduced by low temperature and flooding periods in 1998/99. (7) The grazing patterns in selected foreshore and polder pasture areas revealed the following information on foraging behaviour and the impact of abiotic factors on spatial distribution: (a) both selected pasture areas were characterized by periodical grazing patterns. (b) in the foreshore area goose frequency and average flock size was highest in the mild winter 1997/98 while in the severe winter 1996/97 and after the longer flooding period in the early winter of 1998/99, goose frequency and average flock size was distinctly reduced. (c) in contrast, goose-frequency and average flock size in the polder area was lowest in 1997/98 and highest during the colder weather conditions in 1998/99 when a reduced carrying capacity by flooding was evident in the foreshore area. The severe winter 1996/97 was characterized by intensive grazing, especially after the frost period.

     

Growth of Greater White-Fronted Goose Goslings Relates to Population Dynamics at Multiple Scales

The abundance of greater white-fronted geese (Anser albifrons frontalis) on the Arctic Coastal Plain (ACP) of northern Alaska, USA, has more than tripled since the late 1990s; however, recent rate of annual population growth has declined as population size increased, which may indicate white-fronted geese on the ACP are approaching carrying capacity. We examined rates of gosling growth in greater white-fronted geese at 3 sites on the ACP during 2012–2014 to assist with predictions of future population trends and assess evidence for density-dependent constraints on recruitment. We marked goslings at hatch with individually coded webtags and conducted brood drives during early August to capture, measure, and weigh goslings. Annual estimates of gosling mass at 32 days old (range = 1,190–1,685) indicate that goslings had obtained >60% of asymptotic size. This rate of growth corresponds with that of other goose species and populations with access to high-quality forage and no limitations on forage availability, and is consistent with the overall increase in abundance of white-fronted geese at the ACP scale. Contrary to most previous investigations, age-adjusted mass of goslings did not decline with hatch date. Goslings grew faster in coastal areas than at inland freshwater sites. Taken together, these findings suggest forage was not limiting gosling growth rates in either ecosystem, but forage was of greater quality in coastal areas where goose foraging habitat is expanding because of permafrost subsidence. Spatial patterns of gosling growth corresponded with local-scale patterns of population density and population change; the areas with greatest rates of gosling growth were those with the greatest population density and rates of population increase. We found little evidence to suggest forage during brood rearing was limiting population increase of white-fronted geese on the ACP. Factors responsible for the apparent slowing of ACP-wide population growth are likely those that occur in stages of the annual cycle outside of the breeding grounds. Published 2021. This article is a U.S. Government work and is in the public domain in the USA.     

α-烯醇化酶基因干扰表达对籽鹅卵泡颗粒细胞增殖及凋亡的影响*

目的: 研究α-烯醇化酶(ENO1)基因干扰表达对籽鹅卵泡颗粒细胞增殖、凋亡和细胞周期的影响。方法: 原代培养籽鹅F1级卵泡颗粒细胞(复合培养),将ENO1基因干扰表达重组质粒转染至籽鹅卵泡颗粒细胞。实验分为四组:ENO1干扰表达组(RNAi)、无关序列干扰组(NC)、培养液组(Control)、转染试剂组(Lip)。流式细胞术检测干扰组和对照各组的凋亡率、细胞周期时相性。结果: ENO1基因干扰表达使籽鹅卵泡颗粒细胞增殖速度变慢,凋亡率增加,G2/M期颗粒细胞比例增高。结论: ENO1基因干扰表达可使籽鹅卵泡颗粒细胞周期发生G2/M期阻滞,诱导细胞发生凋亡,抑制细胞增殖。     

Screening and identification of differentially expressed genes in goose hepatocytes exposed to free fatty acid

The overaccumulation of triglycerides in hepatocytes induces hepatic steatosis; however, little is known about the mechanism of goose hepatic steatosis. The aim of this study was to define an experimental model of hepatocellular steatosis with TG overaccumulation and minimal cytotoxicity, using a mixture of various proportions of oleate and palmitate free fatty acids (FFAs) to induce fat‐overloading, then using suppressive subtractive hybridization and a quantitative PCR approach to identify genes with higher or lower expression levels after the treatment of cells with FFA mixtures. Overall, 502 differentially expressed clones, representing 21 novel genes and 87 known genes, were detected by SSH. Based on functional clustering, up‐ and down‐regulated genes were mostly related to carbohydrate and lipid metabolism, enzyme activity and signal transduction. The expression of 20 selected clones involved with carbohydrate and lipid metabolism pathways was further studied by quantitative PCR. The data indicated that six clones similar to the genes ChREBP, FoxO1, apoB, IHPK2, KIF1B, and FSP27, which participate in de novo synthesis of fatty acid and secretion of very low density lipoproteins, had significantly lower expression levels in the hepatocytes treated with FFA mixtures. Meanwhile, 13 clones similar to the genes DGAT‐1, ACSL1, DHRS7, PPARα, L‐FABP, DGAT‐2, PCK, ACSL3, CPT‐1, A‐FABP, PPARβ, MAT, and ALDOB had significantly higher expression levels in the hepatocytes treated with FFA mixtures. These results suggest that several metabolic pathways are altered in goose hepatocytes, which may be useful for further research into the molecular mechanism of goose hepatic steatosis. J. Cell. Biochem. 111: 1482–1492, 2010. © 2010 Wiley‐Liss, Inc.     

Winter Fidelity and Apparent Survival of Lesser Snow Goose Populations in the Pacific Flyway

Abstract The Beringia region of the Arctic contains 2 colonies of lesser snow geese (Chen caerulescens caerulescens) breeding on Wrangel Island, Russia, and Banks Island, Canada, and wintering in North America. The Wrangel Island population is composed of 2 subpopulations from a sympatric breeding colony but separate wintering areas, whereas the Banks Island population shares a sympatric wintering area in California, USA, with one of the Wrangel Island subpopulations. The Wrangel Island colony represents the last major snow goose population in Russia and has fluctuated considerably since 1970, whereas the Banks Island population has more than doubled. The reasons for these changes are unclear, but hypotheses include independent population demographics (survival and recruitment) and immigration and emigration among breeding or wintering populations. These demographic and movement patterns have important ecological and management implications for understanding goose population structure, harvest of admixed populations, and gene flow among populations with separate breeding or wintering areas. From 1993 to 1996, we neckbanded molting birds at their breeding colonies and resighted birds on the wintering grounds. We used multistate mark-recapture models to evaluate apparent survival rates, resighting rates, winter fidelity, and potential exchange among these populations. We also compared the utility of face stain in Wrangel Island breeding geese as a predictor of their wintering area. Our results showed similar apparent survival rates between subpopulations of Wrangel Island snow geese and lower apparent survival, but higher emigration, for the Banks Island birds. Males had lower apparent survival than females, most likely due to differences in neckband loss. Transition between wintering areas was low (<3%), with equal movement between northern and southern wintering areas for Wrangel Island birds and little evidence of exchange between the Banks and northern Wrangel Island populations. Face staining was an unreliable indicator of wintering area. Our findings suggest that northern and southern Wrangel Island subpopulations should be considered a metapopulation in better understanding and managing Pacific Flyway lesser snow geese. Yet the absence of a strong population connection between Banks Island and Wrangel Island geese suggests that these breeding colonies can be managed as separate but overlapping populations. Additionally, winter population fidelity may be more important in lesser snow geese than in other species, and both breeding and wintering areas are important components of population management for sympatric wintering populations.