FP1株番鸭源禽Ⅰ型副粘病毒抗原性分析

为明确FP1株番鸭源禽Ⅰ型副粘病毒强毒与鸡新城疫强毒标准株F48E9之间的抗原性差异,本研究通过交互血凝抑制试验、血清交叉中和试验及雏番鸭免疫攻毒保护试验比较了FP1株番鸭源禽I型副粘病毒强毒与鸡新城疫强毒标准株F48E9之间的抗原性.结果显示同源阳性血清对病毒的血凝抑制效价比异源阳性血清对病毒的血凝抑制效价高2.66～4个滴度;两者之间的抗原相关值R为0.35;对于5日龄经肌注途径免疫接种1羽份量La Sota弱毒疫苗14d后的雏番鸭,以FP1株番鸭源禽Ⅰ型副粘病毒强毒、鸡新城疫强毒标准株F48E9分别攻击后,其保护指数分别为54.5、92.9.以上结果表明,FP1株番鸭源禽Ⅰ型副粘病毒与鸡新城疫强毒标准株F48E9存在较明显的抗原性差异,为鸭副粘病毒病疫苗的研制和该病的防控提供了依据.     

CFSE标记法分析番鸭呼肠孤病毒感染对番鸭回肠淋巴细胞归巢的影响

旨在建立一种可靠的体外活番鸭淋巴细胞的荧光标记方法,并用于分析番鸭呼肠孤病毒感染对雏番鸭回肠淋巴细胞归巢的影响。选择活细胞荧光染剂5（6）-羧基二乙酸荧光素琥珀酰亚胺酯（CFDA-SE,CFSE）对分离的番鸭淋巴细胞进行标记和利用流式细胞术对体外标记的淋巴细胞体内示踪检测分析,并利用该方法对MDRV感染雏番鸭回肠组织的淋巴细胞数量进行流式细胞术和石蜡切片免疫荧光检测分析;结果最终确定CFSE体外标记番鸭淋巴细胞的条件为以PBS为孵育液,终浓度10 μmol·L^-1,37℃ 30 min;试验结果表明番鸭外周血内的CFSE⁺淋巴细胞率基本稳定在2%~5%,CFSE⁺淋巴细胞峰值出现顺序依次为脾、空肠、回肠、盲肠、十二指肠、法氏囊和胸腺;此外,感染MDRV后1~10 d MDRV组中CFSE⁺淋巴细胞率极显著（P<0.01）高于MOCK组,该结果与α4⁺淋巴细胞率和石蜡切片免疫荧光检测结果一致。结果表明本试验CFSE标记的淋巴细胞可用于体内淋巴细胞示踪,初步应用结果提示MDRV感染促进番鸭淋巴细胞向回肠归巢,为进一步阐明MDRV感染的肠道组织致病机制奠定了基础。     

雏番鸭沙门氏菌的分离与鉴定

2014年10月,福建某番鸭场因患疑似鸭沙门氏菌病导致雏番鸭大量死亡,为确诊雏番鸭死亡原因,对送诊的死亡雏番鸭进行细菌分离、生化鉴定和针对沙门氏菌fimW基因作PCR鉴定,并对分离菌进行药敏试验以及动物回归试验,试验结果表明：引起雏番鸭死亡的原因是鸭沙门氏菌病。     

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.     

Use of industrial amino acids to allow low protein concentrations in finishing diets for growing Muscovy ducks

1. Three experiments were performed to assess the effects of decreasing protein concentration in the finishing diets for growing Muscovy ducks (8 to 12 weeks of age) by adding 4 essential amino acids (AAs, lysine, methionine, threonine and tryptophan). Experimental diets with crude protein (CP) contents from 105 to 142 g/kg, were compared with control diets providing 150 to 160 g/kg CP. In each trial, all diets were isocaloric. No significant modification in growth or carcase quality was observed when CP was greater than 124 g/kg in diets supplemented with the 4 essential AAs. 2. There was no advantage in supplying more than 4.3 g of digestible lysine per kg of diet (12.75 MJ ME/kg). When threonine was not added, breast yield decreased significantly (- 4.3%), while omitting tryptophan supplementation did not influence performance. 3. Furthermore, the experiments confirmed that reducing CP had little or no effect on food conversion efficiency and fatness in Muscovy ducklings, unlike the observed situation in broiler chickens.     

Indigenous Muscovy ducks in Congo-Brazzaville. 1. A survey of indigenous Muscovy duck management in households in Dolisie City

A cross-sectional study by means of a questionnaire with open-ended questions and multiple-choice questions was used to collect data on the profile of duck keepers, husbandry practices, and performances, opportunities and constraints of Muscovy duck breeding in households (n = 88) in Dolisie city (Congo-Brazzaville). The study confirmed the common observations on traditional poultry keeping such as scavenging during the day and housing overnight. The flock size (7.7 ± 3 ducks per unit) showed no specialization of husbandry (100% of surveyed flocks were kept for simultaneous production of ducklings, meat and eggs) and a high drake-to-duck ratio (1:3). The hatchability was close to 80.5% ± 13%, whereas the average number of eggs was 13.2 ± 5 per clutch. In addition, a high mortality (80%) was observed in ducklings, which was due to poor feeding, lack of veterinary care and housing conditions. Eggs and live ducks were sold by duck farmers in response to the family needs rather than market price. The three most important findings were as follows: (1) duck keepers were mainly men (80% versus 20% of women); (2) there was no evidence of taboo; and (3) the duck as an exotic bird was not proscribed by cultural beliefs, and therefore development of the Muscovy duck in Congo Brazzaville should be unhindered.     

Isolation and characterization of a reovirus causing spleen necrosis in Pekin ducklings

High rates of mortality for Pekin ducklings have been recorded in several duck farms in China since 2006. Dead ducklings were characterized by spleen necrosis, suggesting microbial infection as a cause of disease. Laboratory investigations led to the isolation of a virus strain from the spleen tissues of dead ducklings, designated DRV-HC. Subsequent experimental infections with DRV-HC resulted in marked spleen necrosis in the ducklings similar to those observed in the natural outbreaks. Electron microscopy of the cultured DRV-HC revealed viral particles that were non-enveloped and icosahedral with a mean diameter of approximately 72 nm. Agar gel precipitating tests showed that the isolate shared a common group-specific antigen with chicken reovirus S1133. DNA sequencing revealed that this isolate was closely related to Muscovy duck reoviruses. Experimental infection with DRV-HC resulted in death of young chicks with necrotic foci in the liver and spleen. To the best of our knowledge, this is the first report of the isolation of a duck reovirus with high virulence in Pekin ducklings and SPF chickens.     

Food restriction and development of thermoregulation in Muscovy ducklings (Cairina moschata)

1. The interaction between the effects of food restriction and cold stress on the development of body temperature, homeothermy index, metabolic rate and body weight were studied in Muscovy ducklings from hatching to 21 d of age.

2. The control group (ad libitum fed) and the food restricted group (fed to zero growth rate for 9 d) both became homeothermic when they were 2 d old with moderate (10°C) cold stress. At severe cold stress (0°C) the control group was homeothermic 5 days after hatching. However the food restricted group did not reach homeothermy at 0°C and showed a large decrease (to hatching level) in homeothermy index at 10°C and 0°C after 9 d of food restriction.

3. Body temperature was lower in the food‐restricted group during restriction and increased by 1°C after 24 h of ad libitum feeding. During food restriction, resting metabolic rate did not increase with age and was lower than the basal and existence metabolic rate predicted by Aschoff and Pohl (1970) and Kendeigh (1970) respectively.

4. The ratio of metabolisable energy (ME) intake to resting metabolic rate was 3 times lower in the food‐restricted group than in the control group (0.09 and 0.27 respectively) on day 9. The availability of ME was more important than age for the development of thermoregulation in Muscovy ducklings. It is concluded that small improvements in the feeding regimen of young ducklings enhance the endurance and consequently reduce mortality from to environmental cold stress in a scavenger poultry system.     

Reversibility of furazolidone-induced cardiotoxicosis in ducklings

Furazolidone cardiotoxicosis was induced in 2 groups (FZ and FZ-CR groups) of newly hatched male Pekin ducklings (100/group) by feeding a ration containing 650 mg of furazolidone/kg of feed (ppm) for 28 days. A third group (control ration, CR group; n = 100) was fed the same ration without furazolidone. On day 28, the control ration was initiated for the FZ-CR group initially given the furazolidone-containing ration, to allow recovery from the effects of the drug, whereas ducklings of the FZ group continued to consume the furazolidone-containing ration. Biweekly, beginning with week 4, ducklings were euthanatized to assess severity of gross lesions and to obtain sections of myocardium for histologic and ultrastructural examination. Clinical evidence (increased weight gain, increased feed consumption, decreased mortality, reduced prevalence of palpable ascites) of regression of cardiotoxicosis of ducklings of the FZ-CR group was nearly complete by day 56 (28 days after cessation of furazolidone intake). Likewise, regression of gross lesions, as measured by overall prevalence of gross lesions, left ventricular volume, and ascites prevalence and severity, were also essentially complete by day 56. Myofibrillar lysis was not seen in sections from the heart (examined ultrastructurally) obtained from ducklings of the CR group that were euthanatized on day 28, 56, or 98. Myofibrillar lysis was detected in all ducklings (4/4) fed furazolidone (FZ and FZ-CR groups) and euthanatized on day 28. Myofibrillar lysis was not seen in the heart of ducklings of the FZ-CR group that were euthanatized on day 56 or 98. Myofibrillar lysis was detected in the heart from all ducklings of the FZ group that were euthanatized on day 56.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ultrastructural alterations in furazolidone-induced cystic testicular degeneration in ducklings

Cystic testicular degeneration was induced in groups of ducklings by feeding furazolidone at 250, 400, 550, or 750 mg per kilogram of feed (ppm) for 4 weeks. In normal ducklings, tall, columnar Sertoli cells predominated in the seminiferous epithelium. In treated ducklings, the mildest ultrastructural alteration was cytoplasmic vacuolation of Sertoli cells. In birds with more severely affected tubules, cytoplasmic vacuolation was more severe and the cells were cuboidal or rounded. The rounded cells desquamated into the tubular lumens, eventually undergoing cytolysis. In birds with the most severely affected tubules, only extensively flattened epithelial cells lined the extremely dilated seminiferous tubules. The interstitium was edematous and compacted between the expanded tubules. Many of the testicular ultrastructural alterations in furazolidone-intoxicated ducklings were similar to those described in the testicles of sodium-intoxicated cockerels.     

An outbreak of duck viral enteritis (duck plague) in domestic Muscovy ducks (Cairina moschata domesticus) in Illinois.

Duck viral enteritis (DVE) was diagnosed in an outbreak of the disease in a resident population of Muscovy ducks (Cairina moschata domesticus) on a privately owned multispecies game bird production facility in Illinois, where it claimed 625 ducks. This disease condition had not been reported previously in domestic ducks in Illinois. Although other varieties and age groups of domestic waterfowl (i.e., black ducks, rhumen ducks, Pekin ducks, ducklings, and geese) were present on the game bird farm, the morbidity and mortality (100%) in this epornitic was solely limited to adult ducks of the Muscovy lineage. The clinical signs in the affected ducks were lethargy, diarrhea, dehydration, and death within 2-3 hr of onset of symptoms. Gross pathologic changes were nonspecific and included ecchymotic hemorrhage, effusion of fluid and blood within body cavities reflective of an acute systemic infectious disease. Light microscopic findings were necrosis of primarily digestive lining epithelium and variable lymphohistiocytic infiltration within mucosal and serosal connective tissues. Intranuclear inclusions resembling characteristic herpetic (i.e., Cowdry type A) inclusions were observed primarily in the digestive, respiratory, and reproductive tracts; liver; and spleen. Esophageal candidiasis, bacteriosis, and systemic Pasteurella anatipestifer infections, thought to be concurrent or opportunistic infections, were present in several ducks. DVE virus was demonstrated in infected Muscovy duck embryo fibroblast cells by direct DVE virus-specific fluorescent antibody staining.     

Lysine requirements of Korean native ducklings for three weeks after hatch

Dietary lysine content in poultry diets is critical to improve feed utilization efficiency, body protein deposition rate, and carcass traits of growing and finishing poultry. The objective of the current study was to estimate the optimum digestible lysine requirements for maximum growth performance, efficient utilization of nitrogen, and carcass traits of male Korean native ducklings for 3 wk after hatch. A total of 720 one-day-old male Korean native ducklings were used in a completely randomized design having 8 dietary treatments to provide a range of digestible lysine content from 0.44 to 1.07%. Ducklings were randomly allotted to 24 floor pens (6 replicates per treatment and 15 ducklings per pen) and were offered the respective diets on an ad libitum basis for the period of study. Body weight and feed intake were measured weekly to calculate feed conversion ratio. At the termination of the experiment, 2 ducklings per pen were euthanized via cervical dislocation to weigh empty body and drumsticks. The digestible lysine requirement was determined by taking a mean value after fitting the data to both linear-plateau and quadratic-plateau models. Digestible lysine requirements for Korean native ducklings for 3 wk after hatch were estimated to be 0.71, 0.74, 0.65 and 1.01% for maximum body weight, daily gain, and daily feed intake, and for minimum feed conversion ratio, respectively.     

低温与维生素E对笼养蛋雏鸭生长性能、抗氧化能力及血糖血脂的影响

本试验旨在研究适温、低温的环境中日粮添加不同水平(20、220和420IU/kg)的维生素E(VE)对蛋雏鸭生长性能、抗氧化能力及血液中血糖血脂浓度的影响。以1日龄蛋雏鸭为试验动物,采用2×3(温度×VE)重复试验设计。结果表明,低温显著降低雏鸭生长性能,提高采食量(P<0.01)和料重比(P<0.01),降低日增重(P<0.01)。与添加20IU/kg处理组相比,添加220和420IU/kg的VE对提高全期平均日增重和改善饲料转化率有显著作用(P<0.01)。温度对血清中总抗氧化能力(T-AOC),丙二醛(MDA)水平无显著影响,而添加220和420IU/kg的VE会使雏鸭血清中总抗氧化能力T-AOC显著升高(P<0.05),丙二醛MDA水平降低。温度对甘油三酯,葡萄糖的影响极显著(P<0.01),甘油三酯、葡萄糖浓度均随温度降低而升高(P<0.01),而随添加VE浓度升高均有降低的趋势(P>0.05)。因此,日粮中添加220和420IU/kg的VE能显著改善生长性能,提高机体抗氧化能力,在一定程度上调节机体血糖血脂代谢。VE添加水平为220IU/kg时在正常育雏温度和低于正常育雏温度(5±1)℃下的生长性能和抗氧化能力均较好。     

Early clinical and morphologic alterations in the pathogenesis of furazolidone-induced toxicosis in ducklings

Clinical and pathologic alterations during the development of furazolidone-induced toxicosis were investigated in a group of 35 newly hatched male Pekin ducklings fed a ration containing 700 mg of furazolidone/kg of feed for 27 days. A control group (n = 25) was fed the same ration without added furazolidone. Every 3 days, ducklings were weighted and palpated for ascites and 3 were chosen at random for euthanasia to determine the severity of lesions and to obtain hearts for gross measurements and ultrastructural study. Clinical alterations in treated ducklings consisted of decreased feed consumption with lower weight gain and nervous signs. Gross pathologic alterations included cardiomegaly with dilatation of all chambers and thinning of the myocardium, pericardial effusion, pulmonary edema and congestion, ascites, and testicular enlargement. Gross lesions were not observed before day 8. The earliest lesion (day 9) was cardiac chamber dilatation, with the left ventricle and left atrium most commonly and most severely dilated. Hearts from ducklings euthanatized on days 6, 12, 18, 24, and 27 were examined ultrastructurally. Myofibrillar lysis was first observed on day 12 in 1 duckling (of 3) and in at least 1 duckling from subsequent euthanasia periods. Myofibrillar lysis did not appear to be uniform among the cardiac chambers.     

牙克石地区雏鸭霉高粱中毒的病因研究

1985年5月,内蒙古牙克石市某个体养鸭户饲养的5010只雏鸭在1个月内相继发病死亡.病鸭主要表现食欲减退,增重缓慢,拱背,腹泻,抽搐,卧地不起等.剖检,肝脏呈土黄色,心肌变性,胆囊胀满.通过流行病学调查、真菌分离与鉴定以及动物接种试验等,确认为霉高粱中毒,其致病真菌是扩展青霉(Penicillium expansum Tink)和鲜绿青霉(Peniciliumviridicatum Westling).     

饲粮苏氨酸水平对北京雏鸭生长性能、胴体品质、免疫机能和血清激素的影响

本试验旨在研究饲粮苏氨酸水平对北京雏鸭生长性能、胴体品质、免疫机能和血清激素的影响。选取320只1日龄健康的北京鸭公鸭,随机分为5组,每组8个重复,每个重复8只。各组饲粮中苏氨酸水平实测值分别为0.65%(对照)、0.69%、0.81%、0.88%和0.98%,试验期为21 d。结果表明:1)饲粮苏氨酸水平对雏鸭平均日增重和平均日采食量有极显著影响(P0.01),对照组雏鸭平均日增重和平均日采食量显著低于其他各组(P0.05)。2)饲粮苏氨酸水平对雏鸭胸肌率有显著影响(P0.05),对照组雏鸭胸肌率显著低于0.69%、0.81%、0.88%水平组(P0.05)。3)饲粮苏氨酸水平对雏鸭法氏囊指数、脾脏指数、胸腺指数影响不显著(P0.05)。饲粮苏氨酸水平对雏鸭法氏囊重和胸腺重有极显著影响(P0.01),对照组雏鸭法氏囊重显著低于其他各组(P0.05),对照组雏鸭胸腺重显著低于0.81%、0.88%水平组(P0.05)。4)饲粮苏氨酸水平对雏鸭血清三碘甲腺原氨酸(T3)含量有显著影响(P0.05),0.81%水平组的血清T3含量最高,显著高于对照组和0.98%水平组(P0.05)。5)苏氨酸需要量分别与平均日采食量、平均日增重和胸肌率呈二次曲线关系,并当三者达到最高值时北京雏鸭的苏氨酸需要量分别为0.860%、0.852%和0.837%。由此可见,饲粮中添加适宜水平的苏氨酸可提高雏鸭生长性能、胴体品质和免疫机能。     

Rhythmic occurrence of sexual behavior and egg laying activity of Muscovy ducks

1. The existence of nychthemeral rhythms in the sexual behaviour of Muscovy ducks, kept under intensive husbandry conditions, was investigated. Studies were also carried out of the relationships between artificial insemination or natural mating times, oviposition time and female fertility. 2. Sexual activity (as measured by the number of complete matings observed) followed a trimodal pattern with peaks of activity in the second to third, 5th to 6th and 10th to 15th hours of the photoperiod. The last peak in sexual activity was the most important in both length and intensity. 3. The rhythm in sexual activity was entrained by the light-dark transition. 4. Female fertility was lowest during the period from 4 h before to 1 h after oviposition and greatest in the periods 8 to 4 h before and 1 to 7 h after oviposition. 5. The periods of maximum female fertility did not coincide with the periods of greatest sexual activity. More than 60% of all matings observed occurred during periods of intermediate female fertility. It would therefore appear that natural mating is not consistent with optimal female reproductive performance under artificial husbandry conditions. 6. The results are discussed in relation to a possible reduction in the number of males necessary in breeder populations in Muscovy ducks with a view to reducing the cost of producing ducklings.     

Serum chemistry alterations, including creatine kinase isoenzymes, in furazolidone toxicosis of ducklings: preliminary findings.

Furazolidone induces a cardiotoxicosis when fed in toxic concentrations to newly hatched ducklings. This preliminary experiment was designed to determine if creatine kinase (CK) isoenzymic activities or other serum analytes would be useful as indicators of these cardiac alterations. Sera from 12 ducklings (six fed a control ration and six fed the control ration with 700 mg furazolidone added per kg of feed [700 ppm] for 28 days) were analyzed for CK isoenzymic activities, electrolytes, nitrogenous metabolites, hepatic enzymic activities, bilirubin, and glucose. Statistically significant differences between control and treated groups were detected for creatine kinase MB (CK-MB, cardiac muscle origin) isoenzymic activity and bilirubin, potassium, calcium, and total carbon dioxide concentrations. Differences other than CK-MB isoenzymic activity were generally explained by factors related to the toxicosis or sample handling. These findings suggest that CK-MB isoenzymic activity may be useful to detect and monitor the progress of cardiac injury in furazolidone toxicosis, thereby increasing the usefulness of this model of dilated cardiomyopathy. Our findings, analyzed on the Kodak Ektachem 700 Dry Chemistry Analyzer, are compared with serum chemistry values reported in the literature.     

Isolation,Identification and Drug Resistance Analysis of Riemerella anatipestifer from Muscovy Duck

In order to understand the drug resistance of Riemerella anatipestifer from Muscovy duck,this study carried out bacterial isolation and culture,Gram staining microscopy,pathogen detection,biochemical test,16S rRNA sequence analysis,PCR identification,drug sensitivity test and drug resistance gene detection for Muscovy duck suspected of Riemerella anatipestifer infection.The results of bacterial isolation showed that on the blood agar medium,the isolated bacteria grew creamy needle tip size colonies with smooth surface,neat edge,luster and translucency.The Gram-negative bacillus brevis was detected by Gram-negative staining microscopy,and it was named GZQN201907.In the biochemical test of GZQN201907,urea reaction was positive,but glucose,maltose,lactose and other biochemical reactions were negative.The 16S rRNA phylogenetic tree was in the same branch as Riemerella anatipestifer.And the OmpA gene of PCR identification results of the isolated strain were positive.The drug sensitivity test was sensitive to 18 antibiotics including cefuroxime,erythromycin and ceftazidime,moderately sensitive to carboxypicillin and ciprofloxacin,and sensitive to neomycin and cotrimoxazole.And the resistance genes could detect the β-lactam resistance genes VIM and TEM,tetracycline resistance genes tetB,macrolide resistance genes ermB and ermF.The results of drug sensitivity test and drug resistance gene detection indicated that GZQN201907 showed the same resistance phenotype and gene detection results for β-lactam,tetracycline and macrolide.In the animal regression test,all the ducklings inoculated with GZQN201907 died within 72 h,while the control group showed no symptoms,indicating that GZQN201907 was virulent to the ducklings.One strain of Riemerella anatipestifer from Muscovy duck was successfully isolated,which laid a foundation for the prevention and treatment of Riemerella anatipestifer from muscovich.     

日粮烟酸水平对肉鸭后期生产性能和脂肪代谢的影响

７２只２１日龄樱桃谷鸭平均分成４组,分别添加０、３０、６０、９０ｍｇ／ｋｇ烟酸进行３周饲养试验。测定平均日采食量（ＡＤＦＩ）、平均日增重（ＡＤＧ）、料重比（Ｆ／Ｇ）、血清总胆固醇（ＴＣＨ）、血清总甘油三酯（ＴＧ）、低密度脂蛋白胆固醇（ＬＤＬ－Ｃ）、高密度脂蛋白胆固醇（ＨＤＬ－Ｃ）。结果表明：①日粮烟酸水平不影响ＡＤＦＩ、ＡＤＧ、Ｆ／Ｇ（Ｐ＞０．０５）,但与ＡＤＦＩ、ＡＤＧ、Ｆ／Ｇ存在显著（Ｐ＜０．０５）或极显著二次曲线关系（Ｐ＜０．０１）。②日粮烟酸水平可能影响ＴＣＨ、ＴＧ、ＬＤＬ－Ｃ、ＨＤＬ－Ｃ,但差异不显著（Ｐ＞０．０５）。当基础日粮烟酸和色氨酸水平分别为３５ｍｇ／ｋｇ和０．１６％时,建议肉鸭后期烟酸添加水平为６０ｍｇ／ｋｇ。