洪江雪峰乌骨鸡和罗曼粉蛋鸡鸡蛋营养成分和蛋品质比较

试验旨在比较洪江雪峰乌骨鸡和罗曼粉蛋鸡的鸡蛋营养成分和蛋品质,为洪江雪峰乌骨鸡蛋用新品系选育提供依据。随机选取40周龄的洪江雪峰乌骨鸡(绿壳)、洪江雪峰乌骨鸡(粉壳)和罗曼粉壳蛋鸡各100只,每品种鸡随机分为5个重复,每个重复20只,在相同饲粮和饲养管理方式下进行饲养,45周龄收集鸡蛋检测营养成分和蛋品质指标。结果表明:洪江雪峰乌骨鸡绿壳蛋的蛋黄比例极显著高于罗曼粉壳蛋(P<0.01),蛋重、蛋壳厚度、哈氏单位极显著低于罗曼粉壳蛋(P<0.01),洪江雪峰乌骨鸡粉壳蛋的蛋重和蛋壳厚度极显著低于罗曼粉壳蛋(P<0.01);洪江雪峰乌骨鸡蛋中的多不饱和脂肪酸和硒元素含量均极显著高于罗曼粉壳蛋(P<0.01),洪江雪峰乌骨鸡绿壳蛋胶原蛋白含量极显著高于罗曼粉壳蛋(P<0.01)。综上所述,洪江雪峰乌骨鸡鸡蛋蛋黄比例高,蛋黄多不饱和脂肪酸、胶原蛋白、硒和锰含量高,适合作为优质禽蛋开发。     

Estimation of the Rate of Egg Contamination from Salmonella‐Infected Chickens

Salmonella enterica serovar Enteritidis (S. Enteritidis) is one of the most prevalent causes for human gastroenteritis and is by far the predominant Salmonella serovar among human cases, followed by Salmonella Typhimurium. Contaminated eggs produced by infected laying hens are thought to be the main source of human infection with S. Enteritidis throughout the world. Although previous studies have looked at the proportion of infected eggs from infected flocks, there is still uncertainty over the rate at which infected birds produce contaminated eggs. The aim of this study was to estimate the rate at which infected birds produce contaminated egg shells and egg contents. Data were collected from two studies, consisting of 15 and 20 flocks, respectively. Faecal and environmental sampling and testing of ovaries/caeca from laying hens were carried out in parallel with (i) for the first study, testing 300 individual eggs, contents and shells together and (ii) for the second study, testing 4000 eggs in pools of six, with shells and contents tested separately. Bayesian methods were used to estimate the within‐flock prevalence of infection from the faecal and hen post‐mortem data, and this was related to the proportion of positive eggs. Results indicated a linear relationship between the rate of contamination of egg contents and the prevalence of infected chickens, but a nonlinear (quadratic) relationship between infection prevalence and the rate of egg shell contamination, with egg shell contamination occurring at a much higher rate than that of egg contents. There was also a significant difference in the rate of egg contamination between serovars, with S. Enteritidis causing a higher rate of contamination of egg contents and a lower rate of contamination of egg shells compared to non‐S. Enteritidis serovars. These results will be useful for risk assessments of human exposure to Salmonella‐contaminated eggs.     

Effect of a single injection of adrenaline on shell ultrastructure in a series of eggs from domestic hens

1. Adrenaline (1 mg in 1 ml water) was administered subcutaneously to three hens to determine whether any changes in the shell ultrastructure of subsequent eggs would occur. 2. The egg shells were examined in a scanning electron microscope after plasma etching. 3. The first three eggs laid by each bird after adrenaline injection were compared with previously-collected normal eggs from the same birds and also with control eggs collected over the same period from three hens which had received no adrenaline. 4. The first egg laid following adrenaline treatment was essentially normal but both the second and third eggs showed severe structural disorganisation at all levels, from the mamillary caps up to the cuticular layer. 5. Eggs laid 20 d or more after adrenaline treatment had reverted to normal. 6. The findings suggest that the abnormal eggs laid after hens have been exposed to disturbance or stress are likely to be affected in not only their external appearance but also to be of poor structural quality.     

Design of laying nests in furnished cages: influence of nesting material, nest box position and seclusion

(1) Preferences for three nesting materials and nest box positions were investigated simultaneously in two trials using a furnished cage: one with 18 individual laying hens and one with 18 groups of 5 hens. Following a habituation period in pre-test cages, every hen or group of hens was tested for 2 d: once without and once with plastic flaps at the entrance of the nest boxes. (2) Hens preferred peat and artificial turf to coated wire mesh for egg laying. (3) One nest box position was clearly preferred to both other nest boxes. The hens' choice of nest box position was influenced by the pre-test cage in which they had been habituated. (4) The presence of plastic flaps at the entrance of the nest boxes had no influence on the proportion of eggs laid on the different nesting materials or on the proportion of floor eggs. (5) Individual and group testing resulted in the same overall results despite the presence of a distinct group effect.     

Comparison of the welfare of layer hens in 4 housing systems in the UK

1. The welfare of hens in 26 flocks (6 conventional cage, 6 furnished cage, 7 barn, 7 free-range) was assessed throughout the laying period using a combination of data on physical health, physiology and injurious pecking, collected by researchers on farm and during post-mortem analysis, and information submitted by producers. 2. There was an effect of housing system on 5 of the indicators recorded by researchers: gentle feather pecks given, feather damage score, proportion of hens with feather damage, proportion of the flock using perches, and faecal corticosterone. 3. Post-mortem analysis revealed several differences between housing systems in skin damage, plumage damage to the vent and abdomen, keel protrusion, bodyweight, and the proportion of hens that were vent pecked and that had old and recent keel fractures. 4. There was an effect of housing system on 5 indicators recorded by producers: proportion of egg shells with calcification spots, proportion of egg shells with blood stains, weight of hens found dead, temporal change in the proportion of egg shells with stains, and temporal change in proportion of hens found dead. 5. Each housing system had positive and negative aspects but overall, hens in barn systems had the highest prevalence of poor plumage condition, old fractures, emaciation, abnormal egg calcification, and the highest corticosterone. Hens in conventional cages sustained more fractures at depopulation than birds in other systems. Vent pecking was most prevalent in free-range flocks. The lowest prevalence of problems occurred in hens in furnished cages. 6. Although housing system had an influence on the hens' physical condition and physiological state, the high prevalence of emaciation, loss of plumage, fractures and evidence of stress is of concern across all housing systems, and suggests that the welfare of modern genotypes is poor.     

Egg shell quality responses of pullets given saline drinking water at different ages

1. Saline drinking water given to pullets before sexual maturity had no effect on their subsequent egg shell quality. 2. Hens receiving saline drinking water from or after laying their first egg produced significantly more egg shell defects than hens receiving town water. 3. The production of eggs with defective shells occurred more rapidly when saline drinking water was given to 40-week-old hens than to hens during the first few weeks of lay. 4. The high incidence of egg shell defects resulting from the use of saline drinking water was reduced to control levels when hens in early lay were given town water for 5 weeks. This response was not observed with 40-week-old hens.     

The relationship between the magnitude of the specific antibody response to experimental salmonella enteritidis infection in laying hens and their production of contaminated eggs.

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.     

Efficacy of infectious bronchitis virus vaccines against heterologous challenge

Twenty-four-week-old white Leghorn layers were inoculated subcutaneously with a killed Newcastle disease-infectious bronchitis (Massachusetts type) virus (MIBV) vaccine. Twenty-eight weeks after vaccination, the birds were challenged intraocularly with the Arkansas strain of infectious bronchitis virus (AIBV) to determine the effects of heterologous virus exposure on egg production, egg quality and serum antibody response of the birds. The challenged hens laid significantly (P less than 0.005) fewer eggs than the unchallenged layers. Eggs laid by the unchallenged groups weighed significantly more (P less than 0.005) than those laid by the challenged groups. Further, the internal quality (Haugh units) and shell quality of eggs laid by the AIBV-challenged hens was significantly (P less than 0.005) inferior to those from the unchallenged hens. In addition, the AIBV-challenged hens laid more soft-shell, misshapen and small eggs than the unchallenged hens. The Arkansas serum haemagglutination inhibition (AIBV-HI) titres of AIBV challenged birds increased up to four weeks after challenge. The corresponding MIBV haemagglutination-inhibition (MIBV-HI) titres decreased during the same period. The study indicates that killed MIBV vaccine offered no protection to birds exposed to heterologous AIBV.     

Nutritional and environmental factors involved in egg shell quality of laying hens.

1. Two experiments were conducted to assess the effects of lighting regime, dietary calcium source and sodium bicarbonate on production variables and egg shell quality of White Leghorn hens. In both experiments, hens were assigned to one of three lighting programmes that provided evening, morning or intermittent (midnight) lighting supplements in addition to natural daylight. Experimental diets used in the first study were formulated to contain (1) ground oyster shell flour, (2) limestone flour, or (3) and (4) the same +2/3 of the calcium source as hen-size oyster shell grit. The same 4 diets plus those containing hen-size limestone or hen-size limestone and oyster shells were used in experiment II. Additionally, diets in the first experiment contained either 0 or 10 g/kg sodium bicarbonate. 2. Hen-day egg production and food consumption were not affected by any of the experimental treatments. Hens fed on oyster shell diets or exposed to intermittent lighting regimes laid eggs of the highest specific gravity. Shell quality, as measured by specific gravity, was not affected by the addition of dietary sodium bicarbonate. 3. As expected, elevated temperatures (greater than 32 degrees C) significantly reduced egg shell quality. However, this effect was variable particularly in experiment II which used younger hens. 4. The shell quality of eggs from hens exposed to intermittent lighting in experiment II was significantly higher in each of the 4 sampling periods: morning (08.00-12.00), afternoon (12.00-16.00), evening (16.00-20.00) and night (20.00-08.00). 5. It is suggested that midnight lighting programmes provide a means of supporting egg shell quality of older laying hens during the summer months without a significant reduction in egg production.     

Responses in egg shell quality to sodium chloride supplementation of the diet and/or drinking water

1. Supplementing the drinking water of 50-week-old laying hens with sodium chloride (NaCl) concentrations between 0.5 and 2 g/l for 7 weeks significantly increased the incidence of egg shell defects and significantly decreased egg shell quality. Dietary NaCl concentrations between 0 and 2 g/kg had little effect on this response. 2. At similar total NaCl intakes egg shell defects were much greater when the NaCl was obtained from the drinking water rather than from the diet. 3. Hens producing eggs with defective shells as a result of receiving saline drinking water failed to recover the ability to lay eggs with good shells after 8 weeks on normal water. 4. The increased incidence of shell damage was not related to decreased food intake or increased egg weight or production.     

Colonization of reproductive organs and internal contamination of eggs after experimental infection of laying hens with Salmonella heidelberg and Salmonella enteritidis

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%).     

The structure of the organic mammillary cores in some weak egg shells

The microscopic structure of the outermost layer of the outer shell membrane containing decalcified mammillary cores of some of the egg shells laid by a large flock of Shaver 288 Starcross hybrids from November 1967 to September 1968 has been examined. It has been found that a high percentage of the weak and thin egg shells contain abnormal organic mammillary cores. The results are discussed with special reference to the recent findings of other workers who have studied the crystalline structure of shell concretions and egg shells laid by hens under climatic stress.     

Effects of Observed Incubation Behavior on Egg Production in Laying Hens of a Commercial Chicken Breed and Detection of Single-Nucleotide Polymorphisms Associated with the Incubation Behavior

Upon contact with laid eggs, avians initiate incubation behavior and stop laying additional eggs. This phenomenon suggests that the productivity of laying hens in free-range facilities may decrease because of frequent contact with laid eggs. Here, we examined whether hens of a commercial breed exhibit incubation behavior in a free-range facility and whether egg productivity subsequently decreases. One-hour observations were performed twice weekly for 3 weeks, during which 9 of 129 hens (7.0%) exhibited incubation behavior (i.e., sitting on eggs) in the free-range facility and were defined as incubating hens. During 4 d of continuous behavioral observation, incubating and non-incubating hens laid the same number of eggs statistically (4.6 and 3.6, on average, respectively); however, incubating hens spent significantly more time on average incubating the eggs (2071.9 min) than did the non-incubating hens (20.9 min; P<0.05), indicating a clear behavioral difference. Subsequently, the incubation behavior and egg productivity of incubating hens and a Silkie Fowl breed hen, which is known to exhibit typical incubation behavior and cessation of laying, were continuously compared for 27 d. The average minutes spent incubating eggs during the observation period increased in both the incubating hens and Silkie Fowl hen and the total time was almost the same (18,088.5 and 23,092 min, respectively). However, the Silkie Fowl hen stopped laying on day 17 after laying 17 eggs, whereas the incubating hens continued laying throughout the observation period. Incubating hens laid an average of 24.5 eggs, indicating that some hens (at least those of the commercial breed used in our study) can continue laying while exhibiting incubation behavior. A single-nucleotide polymorphism associated with incubation behavior was detected on chromosome 4 through genome-wide association analysis.     

Features of eggshell formation in guinea fowl: kinetics of shell deposition, uterine protein secretion and uterine histology

1. Rate of calcium carbonate deposition, duration of eggshell formation, organic composition of the uterine fluid, morphology of the egg shells and histochemistry of the uterus were studied in guinea fowl to analyse the origin of such thick, strong egg shells. 2. The egg shell was linearly deposited from 6.4 h to 21.8 h after the oviposition of the previous egg. The rate of egg shell deposition was similar to that in laying hens. However, the duration of linear shell deposition was increased by 2.1 h relative to that in hens. This explained the increased egg shell weight observed in the guinea fowl. 3. Intervals between oviposition of intra-clutch eggs were 24 h throughout the laying period. Ovulation occurred just after oviposition of the previous egg in the guinea fowl, as previously observed in hens but the duration of egg white protein deposition, of plumping and of initiation of shell mineralisation were all 1.5 h shorter than in domestic hen. 4. Uterine fluid can only be collected during the growth and terminal phase of shell formation. The electrophoretic profiles of the uterine fluid differed between phases and were somewhat different from those previously observed in the hen. Ovalbumin and ovocleidin-17 were both present in the uterine fluid and also in egg shell extract. Ovocleidin-17 was predominant during the growth phase. 5. The histology of the uterus differed slightly in guinea fowl compared to hens. Ovocleidin and ovalbumin are both secreted by the tubular glands. 6. Examination of radial ultrathin sections of eggshell showed, above the mammillary layer, intricate interlacing of adjacent exospherite in guinea fowl in contrast to the continuous columnar microstructure in hens. 7. The kinetics of egg shell deposition largely explains the increased egg shell weight of guinea fowl. The organic matrix proteins may be associated with the contrast between the structural organisation of the guinea fowl egg shell and that of the hen egg shell.     

The effect of changing the excreta moisture of caged laying hens on the excreta and microbial contamination of their egg shells

1. An experiment that included 1440 caged laying hens in 24 experimental units was conducted to determine the effect of differences in excreta moisture on the proportion of dirty eggs and the microbial contamination of eggs that were ostensibly uncontaminated by excreta. Excreta moisture contents were changed by giving the hens diets that contained 4 different concentrations of sodium. 2. Diets containing 1.6, 5, 10 or 15 g/kg dietary sodium were fed ad libitum to 1140 laying hens for a 12-week feeding period. A sample of excreta was collected from each experimental unit each week and its moisture content determined. All eggs produced were classified as clean or dirty according to the European Community Egg Marketing Regulations. A sample of eggs were collected from each experimental unit on 4 separate occasions in the last 4 weeks of the feeding period and the total bacterial numbers on ostensibly clean egg shells were determined. 3. Increasing dietary sodium concentration gave linear (P<0.01) increases in excreta moisture. Each 100 g/kg increase in excreta moisture increased (P<0.001) dirty egg numbers by 0.52% of the total eggs produced. Increasing excreta moisture gave a linear increase (P<0.001) in the (log-transformed) numbers of microorganisms that contaminated ostensibly clean egg shells.     

Dynamics of amino acid and protein metabolism of laying hens after the administration of 15N-labeled wheat protein. 3. Incorporation of 15N into egg shell, egg white and egg yolk

12 colostomized laying hybrids received a ration meeting their requirement of 15N labelled wheat with a 15N excess (15N') of 14.37 atom-% over 4 days. The 15N' of the total ration amounted to 4.47 atom-%. Each hen consumed 135 mg 15N' per day. On another 4 days the same rations with non labelled wheat were fed. The 12 hens laid 56 eggs during the 8 days of the experiment. They were divided into egg shell, white and yolk of egg. In addition, the protein of the white and yolk of egg was precipitated with trichloric acetic acid (TCA) and the nitrogen in these fractions was determined. On average of the 56 eggs, the N quota in the egg shell was 5.3%, in the white of egg 49.1% and in the yolk 45.6%. The atom-% 15N' in the shells of the eggs laid on the first day of the experiment was on average 0.21, whereas only 0.03 and 0.02 atom-% 15N' resp. could be detected in the white and yolks of the eggs. On the first day after the last 15N application the atom-% 15N' in the egg shell and the white of egg was highest and amounted to 2.33 and 2.43 atom-% resp. The highest value of 1.83 atom-% 15N' in the yolk was ascertained 3 days after the last 15N intake. The mean quota of TCA-precipitable N in the white of egg is 97.6% and in the yolk 94.4% of the respective total N. The atom-% 15N' in the non-protein N-compounds was higher than in the protein fractions.     

Pathogenicity and distribution of egg-drop syndrome-1976 virus (JPA-1) in inoculated laying hens

Rhode Island Red laying hens that lacked hemagglutination-inhibition antibody were inoculated orally with the JPA-1 strain of adenovirus isolated from a flock affected with egg-drop syndrome-1976 in Japan and observed for 80 days. Inoculated hens laid abnormal eggs, such as shell-less, soft-shelled, and cracked eggs and those with loss of pigmentation, from 8 days postinoculation (PI). Fifteen out of 16 hens laid abnormal eggs. Egg-production rte fell from 94% to 50% between 13 and 16 days PI. When the abnormal eggs were excluded, egg production was 17%; then it recoverd slowly, reaching 67% by the end of the experiment. The virus was recovered from various organs of inoculated hens from 3 to 7 days PI. Fluorescent antigens of the virus were observed in the epithelial cells and desquamated cells from the epithelium of the uterus and isthmus 10 and 14 days PI.     

Drop of egg production in chickens by experimental infection with an avian metapneumovirus strain PLE8T1 derived from swollen head syndrome and the application to evaluate vaccine

Decreases in egg production and increased incidence of abnormal eggs due to malformation of egg shells were observed in specific pathogen free (SPF) 173-day-old laying hens inoculated intravenously with an avian metapneumovirus (aMPV) strain PLE8T1. This strain was derived from an isolate from broiler birds exhibiting swollen head syndrome (SHS). Some SPF birds inoculated with the virus showed, slight diarrhea without any respiratory symptoms. Thus, the PLE8T1 strain was used as a challenge virus to evaluate efficacy of aMPV vaccines. SPF chickens which received a live attenuated aMPV vaccine (NEMOVAC; Merial) at 7 or 77 days old and an inactivated aMPV vaccine (OVO-4; Merial) at 105 days old were protected against poor egg production caused by the challenge with the PLE8T1 strain. Thus, aMPV, the PLE8T1 strain passaged 22 times after isolation, from birds exhibiting SHS, could induce a drop in egg production in laying hens accompanied by malformation of egg shells. It was suggested that this challenge system could be applied to evaluate the efficacy of aMPV vaccine.     

Effects of experimental infection of fowl with EDS'76 virus,infectious bronchitis virus and/or fowl adenovirus on laying performance

Following BCI4 (EDS'76) virus infection of brown layer hens at 33 weeks of age, production of normally shelled eggs dropped from 87 per cent to 49 per cent within 3 weeks. The production of soft shelled and shell‐less eggs attained a maximum of 33 per cent 3 weeks after infection (p.i.). Shell quality recovered completely within 5 weeks p.i.

Egg production problems in White Leghorns infected with BCI4 virus were less severe and of shorter duration than in brown layers.

Both in brown layers and in White Leghorns total egg production, mean weight of normally shelled eggs, and internal egg quality were not affected following BCI 4 virus infection at 33 and 28 weeks of age, respectively. Besides shell abnormalities no clinical disease symptoms were observed. Vaccination with a commercial EDS'76 vaccine (Nobivac EDS'76^®) at 17 weeks of age had no adverse effects on laying performance and provoked adequate immunity against challenge at 33 weeks of age. The same observations were made following BCI4 virus infection at 17 weeks of age.

After infectious bronchitis virus (IBV) (H52 virus) infection of laying fowl the percentage of eggs with shell aberrations (rough, misshapen and/ or soft shells) increased to a maximum of 8 per cent, total egg production was depressed, mean egg weight was reduced I to 2 grams, and up to 10 Per cent of normally shelled eggs showed watery, not ropy thin albumen. This abnormally thin albumen was observed in a considerably higher proportion of eggs with shell defects than in normally shelled eggs. No turbidity of the thick albumen was observed and no symptoms of respiratory disease were noticed.

The severity and duration of adverse effects of IBV infection on laying performance depend very much on the stage of production in which the infection occurs. Following IBV infection at the onset of production a much severer drop in total production and in production of normally shelled eggs, a greater increase in the number of abnormally shelled eggs, and more lasting adverse effects on egg weight and internal egg quality were observed, in comparison with infection after peak production. Compared with single infections, a combined BC14 virus and IBV infection of brown layers at 33 weeks of age resulted in greatly potentiated adverse effects on total egg production, number of eggs with aberrant internal quality, and duration of production problems.

Following a combined BC14 virus and IBV infection, in a great proportion of eggs with shell defects and watery thin albumen, turbidity of the thick albumen was observed also, probably due to combined effects on the uterus of both IBV and BC14 virus.

BC14 virus infection did not reinforce the adverse influence of IBV infection on egg weight.

The same observations as described for the combined BC14 virus and IBV infection were made following BC14 virus infection of fowl previously infected with IBV.

It is concluded that changes of internal egg quality in field cases of EDS'76 are most likely due to subclinical IBV infections.

After infection of brown layers at 33 weeks of age with fowl adenovirus 66 (FA V 66) neither symptoms of clinical disease were observed nor effects on egg production, egg weight, and egg quality. Also, in a combined infection with FA V66, IBV, and BCI4 virus, no pathogenic significance could be attributed to the FAV.     

Lead contamination of chicken eggs and tissues from a small farm flock.

Twenty mixed-breed adult laying hens from a small farm flock in Iowa were clinically normal but had been exposed to chips of lead-based paint in their environment. These chickens were brought to the Iowa State University Veterinary Diagnostic Laboratory, Ames, Iowa, where the concentration of lead in blood, eggs (yolk, albumen, and shell), and tissues (liver, kidney, muscle, and ovary) from 5 selected chickens was determined over a period of 9 days. Blood lead levels ranged from less than 50 to 760 ppb. Lead contamination of the yolks varied from less than 20 to 400 ppb, and shells were found to contain up to 450 ppb lead. Albumen contained no detectable amount. Lead content of the egg yolks strongly correlated with blood lead levels. Deposition of lead in the shells did not correlate well with blood lead levels. Mean tissue lead accumulation was highest in kidneys (1,360 ppb), with livers ranking second (500 ppb) and ovarian tissue third (320 ppb). Muscle contained the lowest level of lead (280 ppb). Lead contamination of egg yolks and edible chicken tissues represents a potential public health hazard, especially to children repeatedly consuming eggs from contaminated family-owned flocks.