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1.
Because egg yolk and albumen differ substantially in their abilities to support bacterial growth, the initial level and location of Salmonella enteritidis deposition are critical for determining whether proposed standards for refrigerating eggs are likely to protect public health by preventing extensive microbial multiplication. In the present study, three groups of laying hens were infected with oral doses of approximately 10(9) cells of different S. enteritidis strains (two were phage type 4 and one was phage type 13a) in two replicate trials. For all three S. enteritidis strains, the incidence of yolk contamination (approximately 2.5% overall) was significantly greater than the incidence of albumen contamination (approximately 0.5% overall). The phage type 13a strain was less often isolated from fecal samples at 2 wk post-inoculation than were the phage type 4 strains, but no significant differences between strains were observed in the incidence of egg contamination. Most freshly laid contaminated eggs contained fewer than 1 S. enteritidis cell/ml of egg yolk or albumen, and no sample contained more than 67 S. enteritidis cells/ml. 相似文献
2.
Laying hens were inoculated orally, intracloacally (IC), or intravenously (IV) with Salmonella enteritidis phage type 8 isolates from a human (E700-87) eggs (Y-8P2), or the ovary of a hen (27A). Oral or IV inoculation of 2 x 10(8) to 4 x 10(8) colony-forming units (CFU) of E700-87 caused depression, anorexia, reduced egg production, diarrhea, and some mortality. Lower doses resulted in milder clinical signs. S. enteritidis was cultured from the shells of a few eggs but not from egg contents. Fecal shedding persisted for up to 6 weeks in some birds. Isolate Y-8P2 (10(6) CFU) also caused anorexia, diarrhea, and a drop in egg production. Hens inoculated orally or IC were less severely affected than those inoculated IV. Fecal shedding was intermittent and lasted up to 18 days. Eggshells from the IC-inoculated birds had the highest rate of contamination, and S. enteritidis was isolated from the albumen of 11 and yolk of three of 726 eggs. Oral inoculation of 10(6) CFU of isolate 27A resulted in a bacteremic infection with seeding of the liver, spleen, peritoneum, ovule, and oviduct. However, the birds remained clinically normal with normal egg production. S. enteritidis was cultured from the yolk and albumen of a small number of eggs until 11 days postinfection. Antigen prepared from S. enteritidis detected antibody in more sera than did commercially available S. pullorum antigen in agglutination tests. 相似文献
3.
Production of Salmonella enteritidis-contaminated eggs by experimentally infected hens 总被引：9，自引：0，他引：9
Laying hens of three different ages were experimentally infected with a strain of Salmonella enteritidis by either oral inoculation or contact transmission. Total egg production was depressed in exposed hens of all three age groups. Persistent intestinal shedding was observed in a small number of hens. Eggs with contents contaminated by S. enteritidis were produced by exposed hens at a high frequency, but only during a fairly short period of time that extended through approximately 1 week postinoculation for older hens and through 2 weeks for younger hens. S. enteritidis was recovered from whole yolks and albumen of these eggs at similar frequencies, but not from the content of yolks. Eggs with contaminated shells were also produced, but at a lower frequency. Contaminated eggs were produced by orally inoculated and contact-exposed hens at similar frequencies. S. enteritidis was not isolated from the contents of eggs laid by hens infected with other S. enteritidis strains. 相似文献
4.
Detecting infected laying flocks is a vital part of many efforts to control egg-associated transmission of Salmonella enteritidis to humans. The relationship between the development of a specific antibody response in infected hens and the deposition of S. enteritidis in eggs is important for establishing the epidemiologic relevance of serologic testing methods. In two trials, laying hens were infected with large oral doses of phage types 13a and 14b isolates of S. enteritidis. Approximately 38% of all infected hens produced at least one contaminated egg, at an overall incidence of 5.2%, between 3 and 23 days postinoculation. As determined by enzyme-linked immunosorbent assay with an S. enteritidis flagellar antigen, 91.7% of inoculated hens produced specific serum antibodies. Although hens with very high antibody titers were associated with a significantly elevated frequency of egg contamination, a consistently direct relationship was not evident between the magnitude of the antibody responses of individual hens and the frequency at which they laid contaminated eggs. Accordingly, although serologic tests can be valuable screening tools for preliminary detection of S. enteritidis infections in poultry, the magnitude of the antibody responses detected in individual hens may not predict the overall risk of egg contamination associated with particular laying flocks. 相似文献
5.
1. Anticoccidials are widely used as food additives to prevent and treat coccidiosis. They are licensed for use in a prescribed concentration and during a specific time interval with broilers and pullets, but not for laying hens. 2. This study was set up to develop a new high pressure liquid chromatography (HPLC) method to detect clazuril (CZ: (+/-)-2-chloro-alpha-(4-chlorophenyl)-4-(4,5-dihydro-3,5-dioxo-1,2,4-triazin-2(3H)-yl)-benzeneacetonitrile) in egg yolk and albumen and in plasma; to investigate both the presence of residues of CZ in eggs and its pharmacokinetic behaviour in laying hens. 3. A single oral dose (3 mg/kg BW) and multiple oral doses (3 mg/kg BW for 5 d) were investigated. The analytical method gave very good recovery (64 to 74%) in the three different matrices (yolk, albumen and plasma); precision and accuracy were within 11%. 4. After a single dose no residue was detected in eggs collected for up to 10 d, while following multiple dose treatment, CZ residues were detected until 10 d after the end of treatment. The concentration of the drug was higher in yolk than in albumen with a maximum ratio of 10 : 1. 5. Pharmacokinetics of CZ in laying hens after a single dose showed a detectable concentration of the drug up to 24 h. It reached a steady state after the third administration in multiple dosing. 6. Although further studies are necessary, these results indicate that a single oral dose of CZ could be used as an anticoccidial for laying hens due to the lack of residues in eggs. 相似文献
6.
Experimental infection models are valuable tools for understanding and preventing the deposition of Salmonella enteritidis inside eggs. Oral inoculation is believed to closely simulate naturally occurring S. enteritidis infections of chickens, but oral infection studies have often generated relatively low frequencies of egg contamination. The present study assessed whether repeated in vivo passage of an S. enteritidis strain could affect its ability to cause egg contamination in experimentally infected hens. The incidence of egg contamination was determined in groups of hens inoculated orally with either a phage type 13a S. enteritidis strain or derivatives of this parent strain that were obtained by three successive rounds of passage and reisolation from tissues of infected hens. Passaged S. enteritidis isolates recovered from ovaries and oviducts induced a significantly higher incidence of egg contamination (16.97%) than was attributed to the parent strain (8.27%). However, passaged S. enteritidis isolates recovered from livers and spleens were not associated with a significantly increased frequency of deposition in eggs. By either inducing or selecting for the expression of relevant microbial properties, passage of S. enteritidis through reproductive tissues of chickens may be useful for improving the efficiency at which experimental infection models produce egg contamination. 相似文献
7.
Neutralizing antibodies to CELO virus and to avian adenovirus-associated virus (A-AV) were detected in the albumen of eggs from four hens inoculated with these viruses. The antibody concentrations of serum, yolk, and albumen were determined before inoculation and at various times postinoculation (PI) by enzyme-linked immunosorbent assay (ELISA) and virus-neutralization (VN) tests. The antibody concentration in albumen was 0.3% to 1.0% of that detected in serum and yolk. Uninoculated hens showed no detectable antibody in serum, yolk, or albumen. It is suggested that the presence of antibody in the egg albumen may play a role in egg-transmission of viruses. 相似文献
8.
Yang B 《New Zealand veterinary journal》1992,40(3):117-119
Japanese quails were inoculated orally with 1 x 10(10) colony-forming units of Salmonella enteritidis phage type 4 isolated from chicks to obtain information concerning S. enteritidis infection and egg transmission. The inoculation resulted in a bacteraemic infection with seeding of the liver, spleen, intestine, peritoneum, ovule, ovary and oviduct. Some infected birds showed diarrhoea, ruffled feathers, depression, loss of appetite and death. However, most infected birds remained clinically normal with normal egg production. Salmonella enteritidis was isolated from the albumen of 7, yolk of 15, shell of 13, and shell membrane of 15 of 164 eggs. The experiment suggests that S. enteritidis phage type 4 is invasive for Japanese quails and the infected eggs laid by S. enteritidis infected quails are probably the result of transovarian infection. 相似文献
9.
不同周龄母鸡鸡蛋及不同蛋壳质地鸡蛋的蛋品质比较 总被引：1，自引：0，他引：1
本文比较了同一品种不同周龄(26、40周龄和64周龄)母鸡所产蛋的蛋壳品质和蛋品质,包括蛋重、蛋壳相对重、蛋形指数、蛋壳强度、蛋壳厚度、蛋黄颜色、蛋黄指数、蛋黄比率、哈氏单位、蛋清pH值。之后,还比较了该鸡种不同蛋壳质地鸡蛋(正常蛋和砂壳蛋)之间上述指标的差异。结果表明:在不同周龄母鸡所产蛋之间,蛋重、蛋黄指数、蛋黄比率、哈氏单位等均存在显著差异(p<0.05),而蛋壳厚度之间差异不显著(p>0.05)。此外,蛋重、蛋形指数、蛋黄颜色、蛋黄比率随着母鸡周龄的增加呈上升趋势,而蛋壳强度、蛋壳相对重、哈氏单位、蛋黄指数、蛋清pH值呈下降趋势。最后,蛋壳质地不同的鸡蛋(正常蛋与砂壳蛋)之间,蛋重、蛋壳相对重、蛋壳强度、蛋清pH值之间存在极显著差异(p<0.01),而其他参数之间差异不显著(p>0.05)。 相似文献
10.
In Experiment 1, mature laying hens were inoculated intravaginally with 10(6) colony-forming units of Salmonella enterica serovar enteritidis (S. enteritidis), Salmonella typhimurium, Salmonella infantis, Salmonella hadar, Salmonella heidelberg, or Salmonella montevideo to compare their abilities to colonize the reproductive organs of chickens and to contaminate eggs. Salmonella enteritidis was more frequently recovered (from 11 of 40 eggs, 27.5%) than the other serovars, and especially the inner shell was contaminated with these organisms in 10 of 40 eggs (25.0%). The contamination rates and the viable counts in cloaca were significantly (P < 0.05) higher in hens inoculated with S. enteritidis than in those inoculated with the other serovars at 4 days postinoculation (PI). In the vagina, the positive rates were 90%-100% in hens inoculated with S. enteritidis, and the viable counts of the organisms in this portion were significantly (P < 0.05) higher than those of the other serovars at 2, 4, and 7 days PI. The ceca were colonized similarly by each serovar at 7 days PI. The spleen and ovary were infected with S. enteritidis in three and one hen, respectively. No Salmonella was recovered from liver and peripheral blood in any hen. Salmonella enteritidis was recovered from other oviductal portions than the vagina (10%-20%), whereas no forming egg was contaminated in the oviduct. In Experiment 2, the in vitro adherence of these six serovars to the vaginal epithelium was compared with vaginal explants. The mean number of S. enteritidis attaching to the secondary villi in the vaginal lumen was significantly (P < 0.05) higher than those of the other serovars. These results suggest that S. enteritidis has a specific advantage over the other Salmonella serovars by its capacity to colonize the vaginal tissues of hens, and this higher affinity of S. enteritidis to the vagina may play a significant role in the production of many S. enteritidis-contaminated eggs. 相似文献
11.
Bacteriologic culturing of environmental samples taken from sources such as manure pits and egg belts has been the principal screening tool in programs for identifying commercial laying flocks that have been exposed to Salmonella enteritidis and are thus at risk to produce contaminated eggs. Because airborne dust and aerosols can carry bacteria, air sampling offers a potentially efficient and inexpensive alternative for detecting S. enteritidis in poultry house environments. In the present study, an electrostatic air sampling device was applied to detect S. enteritidis in a room containing experimentally infected, caged laying hens. After oral inoculation of hens with a phage type 13a S. enteritidis strain, air samples were collected onto agar plates with the electrostatic sampling device, an impaction air sampler, and by passive exposure to the settling of aerosols and dust. Even though the floor of the room was cleaned once per week (removing most manure, dust, and feathers), air samples were positive for S. enteritidis for up to 4 wk postinoculation. On the basis of both the number of S. enteritidis colonies observed on incubated agar plates and the frequency of positive results, the efficiency of the electrostatic device was significantly greater than that of the passive exposure plates (especially at short collection intervals) and was similar to that of the far more expensive impaction sampler. The electrostatic device, used for a 3-hr sampling interval, detected airborne S. enteritidis on 75% of agar plates over the 4 wk of the study. 相似文献
12.
1. The objectives of this study were to evaluate the effects of feed intake on laying performance, egg quality and egg composition in a Fat line and a Lean line during the laying period (34 to 54 weeks of age). 2. The experiment was a 2 × 2 factorial design with two dietary intake levels (nutrition recommendation and 75% of recommendation) and two broiler genotypes (Fat line and Lean line). Hens (384 of each line) were randomly divided at 23 weeks of age into 4 treatments, with each treatment represented by 12 replicates of 16 birds each. The experiment started when the rate of lay reached 5% and continued until 54 weeks of age. 3. The results indicated that there was a significant interaction between daily feed intake and genotype on egg production, egg weight, percentage yolk, yolk/albumen ratio and yolk cholesterol content. Fat line hens produced significantly more eggs and had a lower incidence of cracked eggs than the Lean line hens. The reduction in feed intake decreased egg weight and increased egg production, egg-shape index and cholesterol content of yolk significantly. 相似文献
13.
1. The egg yolk: albumen (Y:A) ratio during the laying year was investigated in a commercial strain (Hisex) when natural zeolite was added to a layer's diet. 2. Dietary natural zeolite (NZ) increased both egg weight and albumen weight, while yolk weight was not significantly affected. 3. The Y:A ratio was less (more albumen) in eggs laid by hens on zeolite treatments. It was concluded that by feeding NZ it is possible to alter the Y:A ratio. 相似文献
14.
Internal contamination of eggs laid by hens infected with Salmonella enteritidis has been a prominent international public health issue since the mid-1980s. Considerable resources have been committed to detecting and controlling S. enteritidis infections in commercial laying flocks. Recently, the Centers for Disease Control and Prevention also reported a significant association between eggs or egg-containing foods and S. heidelberg infections in humans. The present study sought to determine whether several S. heidelberg isolates obtained from egg-associated human disease outbreaks were able to colonize reproductive tissues and be deposited inside eggs laid by experimentally infected hens in a manner similar to the previously documented behavior of S. enteritidis. In two trials, groups of laying hens were orally inoculated with large doses of four S. heidelberg strains and an S. enteritidis strain that consistently caused egg contamination in previous studies. All five Salmonella strains (of both serotypes) colonized the intestinal tracts and invaded the livers, spleens, ovaries, and oviducts of inoculated hens, with no significant differences observed between the strains for any of these parameters. All four S. heidelberg strains were recovered from the interior liquid contents of eggs laid by infected hens, although at lower frequencies (between 1.1% and 4.5%) than the S. enteritidis strain (7.0%). 相似文献
15.
旨在利用从藏灵菇中筛选的可显著降低血清胆固醇和耐受胃肠道逆环境的副干酪乳杆菌KL1菌株制备微生态制剂,探讨该制剂在低胆固醇鸡蛋生产中对蛋鸡生产性能、蛋品质及鸡蛋中胆固醇含量的影响。本试验将120只30周龄健康状态良好且产蛋率接近的农大3号矮小蛋鸡随机分为低、中、高剂量试验组和对照组,每组5个重复,每个重复6只蛋鸡,试验组在基础饲粮中分别添加105、106、107 CFU·（只·d）-1副干酪乳杆菌KL1微生态制剂,对照组饲喂基础饲粮,连续饲喂10周。对蛋鸡的生产性能、蛋品质和鸡蛋中的胆固醇进行测定和计算。结果表明：1）中剂量组的蛋鸡饲养日产蛋率与对照组相比有显著提高（P<0.05）;2）与对照组相比,中、高剂量组的蛋壳强度、蛋壳厚度和血清钙水平有显著提高（P<0.05）,蛋黄相对重有极显著提高（P<0.01）;3）低、中、高剂量组的蛋黄胆固醇含量及血清总胆固醇（TC）、甘油三酯（TG）含量均极显著低于对照组（P<0.01）;高剂量组的血清高密度脂蛋白胆固醇（HDL-C）和低密度脂蛋白胆固醇（LDL-C）含量分别极显著高于对照组（P<0.01）和显著低于对照组（P<0.05）。在饲粮中添加副干酪乳杆菌KL1微生态制剂可显著提高蛋鸡生产能力和蛋壳品质,降低鸡蛋中胆固醇含量,总体来看,以106 CFU·（只·d）-1作为最终添加剂量效果最佳,在低胆固醇鸡蛋的生产中具有良好的应用价值。 相似文献
16.
Internal contamination of eggs by Salmonella Enteritidis has been a significant source of human illness for several decades and is the focus of a recently proposed U.S. Food and Drug Administration regulatory plan. Salmonella Heidelberg has also been identified as an egg-transmitted human pathogen. The deposition of Salmonella strains inside eggs is apparently a consequence of reproductive tissue colonization in infected laying hens, but the relationship between colonization of specific regions of the reproductive tract and deposition in different locations within eggs is not well documented. In the present study, groups of laying hens were experimentally infected with large oral doses of Salmonella Heidelberg, Salmonella Enteritidis phage type 13a, or Salmonella Enteritidis phage type 14b. For all of these isolates, the overall frequency of ovarian colonization (34.0%) was significantly higher than the frequency of recovery from either the upper (22.9%) or lower (18.1%) regions of the oviduct. No significant differences were observed between the frequencies of Salmonella isolation from egg yolk and albumen (4.0% and 3.3%, respectively). Some significant differences between Salmonella isolates were observed in the frequency of recovery from eggs, but not in the frequency or patterns of recovery from reproductive organs. Accordingly, although the ability of these Salmonella isolates to colonize different regions of the reproductive tract in laying hens was reflected in deposition in both yolk and albumen, there was no indication that any specific affinity of individual isolates for particular regions of this tract produced distinctive patterns of deposition in eggs. 相似文献
17.
1. In organic egg production, forage material as part of the diet for laying hens is mandatory. The purpose of the present study was to examine the effect of feeding with forage materials including maize silage, herbs or kale on egg production and various egg quality parameters of the shell, yolk colour, egg albumen, sensory properties, fatty acid and carotenoid composition of the egg yolk. 2. A total of 5 dietary treatments were tested for 5 weeks, consisting of a basal organic feed plus 120?g/hen.d of the following forage materials: 1) maize silage (control), 2) maize silage incl. 15?g/kg basil, 3) maize silage incl. 30?g/kg basil, 4) maize silage incl. 15?g/kg thyme, or 5) fresh kale leaves. Each was supplied to three replicates of 20 hens. A total of 300 hens was used. 3. Feed intake, forage intake and laying rate did not differ with treatment, but egg weight and egg mass produced increased significantly with the kale treatment. 4. The egg shell strength tended to be higher with the kale treatment, and egg yolk colour was significantly more red with the kale treatment and more yellow with basil and kale treatments. The albumen DM content and albumen gel strength were lowest with the thyme treatment. By sensory evaluation, the kale treatment resulted in eggs with less sulphur aroma, higher yolk colour score, and more sweet and less watery albumen taste. Furthermore, the eggs of the kale treatment had significantly higher lutein and β-carotene content. Also, violaxanthin, an orange xanthophyll, tended to be higher in kale and eggs from hens receiving kale. 5. In conclusion, forage material, especially basil and kale, resulted in increased egg production and eggs of high and differentiable quality. 相似文献
18.
肠炎沙门氏菌污染饲料对鸡蛋安全的影响 总被引：2，自引：0，他引：2
本研究选用160只60周龄白来航蛋鸡,随机分为4组,分别一次性采食30g添加了0、4.7×102、4.7×105、4.7×108cfu肠炎沙门氏菌(SE)的饲料,然后用特异性PCR法对试验鸡所产鸡蛋的不同部位进行SE检测,并观察记录生产性能。结果显示,对照组鸡蛋各部位均为阴性,试验组的蛋壳、壳膜、蛋黄、蛋白均能检测到SE,且随染菌量的增大,检出率增高。当摄入108cfu的SE时,会降低产蛋率,但对鸡蛋的表观性状没有显著影响,成为危害人类健康的潜在隐患。 相似文献
19.
《The Journal of Applied Poultry Research》2014,23(2):196-203
The objective of this study was to evaluate selected morphological characteristics and the chemical composition of turkey eggs of different weight classes. The percentage of eggs weighing ≥100 g increased to 46.66% in wk 23. Eggs weighing 95 and 110 g had lower yolk content (3.05 and 4.86%) and higher albumen content (by 3.16 and 5.21%) compared with eggs weighing 80 g. The total protein content of the albumen increased (from 9.93 to 10.71%) and the water content of the albumen decreased (from 88.30 to 87.59%) with an increase in egg weight. Albumen weight per gram of yolk increased from 1.87 to between 2.18 and 2.42 g in larger eggs. The energy density of the egg decreased from 5.68 to 4.90 kJ/g with an increase in egg weight, and the energy density of the yolk remained at a similar level in all egg weight classes. The other analyzed yolk and shell parameters were not affected by egg weight. The highest energy and total protein content of the yolk was observed in wk 14 of the laying season. No correlations were found between the progress of the laying cycle and eggshell percentage and the water content of the yolk. The values of the remaining egg parameters varied over the laying season. 相似文献
20.
Effects of Chinese herbal mixture on performance,egg quality and blood biochemical parameters of laying hens 
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下载免费PDF全文 X. L. Li Z. B. Wang T. S. Xu 《Journal of animal physiology and animal nutrition》2016,100(6):1041-1049
The aim of the study was to evaluate the effect of Chinese herbal mixture (CHM) in laying hen diets on performance, egg quality and egg nutrition components, as well as selected blood biochemical parameters. A total of 270 Lohmann Brown laying hens, 24 week of age, were randomly distributed into three dietary treatments and fed for 6 week. The CHM was used at the levels of 0%, 0.5% and 1.0% in the diets of the control and two treatment groups respectively. Each dietary treatment was divided into five replicates, comprising of 18 hens each. Hens were housed in a 3‐tier battery system. Feed and water were provided ad libitum. Blood samples and eggs were collected at the end of the experiment. The results showed that dietary treatments did not affect egg weight, mortality, eggshell thickness, albumen height, Haugh units, eggshell‐breaking strength and egg‐shape index. Dietary supplementation of CHM significantly improved (p < 0.05) laying rate and the lowest feed conversion ratio were observed with 1.0% CHM supplementation diets. CHM supplementation decreased (p < 0.05) cracked‐egg rate, egg yolk cholesterol, blood serum levels of cholesterol, triglyceride, low‐density lipoprotein cholesterol (LDL‐C) and alanine aminotransferase (ALT) and increased blood serum levels of high‐density lipoprotein cholesterol (HDL‐C). No differences in serum total protein, serum albumen, serum glucose and aspartate amino transferase (AST) were observed in hens fed CHM. In conclusion, dietary supplementation with CHM improved egg production and egg quality and reduced serum cholesterol concentrations in laying hens. Dietary supplementation of 1.0% CHM in layer diets may be a feasible means of producing eggs with lower cholesterol and higher egg yolk phospholipid contents for health conscious consumers. 相似文献