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PubMed1977

The effect of Marek's disease vaccination and day-old debeaking on the performance of growing pullets and laying hens.

In a 2 X 2 completely randomized factorial design, four hundred day-old Single Comb White Leghorn pullets were randomly assigned to four treatment combinations of vaccinated, non-vaccinated, debeaked and non-debeaked groups. Vaccination and debeaking were performed at day-old by administering 2,000 P.F.U. of HVT vaccine/chick and by removing approximately 2/3 of the upper beak, respectively. All the data were analyzed at 5% level of probability. Vaccination reduced feed consumption significantly only during the early growing period of the first 12 weeks, whereas debeaking caused a significant reduction in feed consumption throughout the experimental period of 80 weeks. Mortality during the 20-week growing period was not affected by either vaccination or debeaking. During the laying period (20-80 weeks of age), vaccination reduced the mortality numerically, while debeaking reduced the mortality significantly. Final body weight, hen-day egg production, egg weight, albumen height and egg shell thickness were not influenced by either vaccination, debeaking or a combination of the two. Debeaking had no effect on the incidence of blood-spotting in the eggs. Vaccination, however, significantly reduced percent blood spots in the eggs. Day-old debeaking effectively prevented the occurrence of cannibalism.

Animals↗

PubMed2003

P19: a female and tissue specifically expressed gene in Schistosoma mansoni, regulated by pairing with the male.

A female-specific sequence was isolated from a cDNA library of Schistosoma mansoni and further characterized. Expression of the corresponding gene (p19) depends on pairing with a male. In situ hybridization and immunohistology experiments revealed exclusive expression of the gene in the cells of the vitellarium, suggesting a function in egg formation. In addition, experimental evidence for cross-linking of the protein under oxidative conditions supports the assumption that the p19 gene may code for an egg-shell precursor protein.

Amino Acid Sequence↗

PubMed2000

Four linked outbreaks of Salmonella enteritidis phage type 4 infection--the continuing egg threat.

Four outbreaks of Salmonella enteritidis phage type (PT) 4 occurred among guests at functions for which a single commercial caterer supplied food. Retrospective cohort studies were used to describe the epidemiology of three of these outbreaks and identify the vehicle(s) responsible. Of 172 guests at these three events, 47 fitted the clinical case definition for illness and 24 cases were confirmed to have S. enteritidis PT4 infection. Food containing raw egg was identified epidemiologically as the likely vehicle of infection in two of the three outbreaks (odds ratios (OR) and 95% confidence intervals 9.1 (2.2-39.9) and 6.9 (1.2-46.4)). Logistic regression analysis yielded OR = 10.7 (p = 0.0022) and OR = 9.3 (p = 0.015) for egg consumption in two of the outbreaks. These outbreaks highlighted the continuing need to remind the public and commercial caterers of the potential high risks of contracting salmonella from shell eggs. Education of caterers includes advice to obtain eggs and other products from reputable and identifiable suppliers.

Confidence Intervals↗

PubMed1993

A comparison of Salmonella enteritidis phage types from egg-associated outbreaks and implicated laying flocks.

Infections due to Salmonella enteritidis are increasing worldwide. In the United States, between 1985 and 1989, 78% of the S. enteritidis outbreaks in which a food vehicle was identified implicated a food containing raw or lightly cooked shell eggs. Under a US Department of Agriculture regulation published in 1990, eggs implicated in human food-borne S. enteritidis outbreaks were traced back to the source flock. The flock environment and the internal organs of a sample of hens were tested for S. enteritidis. We compared the S. enteritidis phage types of isolates from 18 human, egg-associated outbreaks and the 15 flocks implicated through traceback of these outbreaks. The predominant human outbreak phage type was recovered from the environment in 100% of implicated flocks and from the internal organs of hens in 88% of implicated flocks we tested. The results support the use of phage typing as a tool to identify flocks involved in human S. enteritidis outbreaks.

Animals↗

PubMed1993

Egg viability in urinary schistosomiasis. I. New methods compared with available methods.

A new method of quantifying viability and hatchability of Schistosoma haematobium eggs in urine has been developed. It consists of filtering urine samples through Nytrel filters followed by mercurochrome staining to assist in the detection of viable (motile) miracidia in egg shells, and iodine staining to show hatched miracidia. The new method is compared with two existing techniques for viability/hatchability determination, centrifugation hatching and Nuclepore filtration trypan blue staining. Seventy-three egg positive urine samples are compared; the overall proportions of viable eggs are very close for centrifugation hatching and the new method, but 33% of eggs are lost in centrifugation and 19% of eggs are unclassifiable by Nuclepore filtration trypan blue staining. The main advantages and disadvantages of the new and existing methods are described and discussed; the cheapness, simplicity and ease of performance of the new method make it suitable for large-scale field use. Suggestions for improvements and standardization of the new method are made.

Animals↗

PubMed1996

Chick embryos as an alternative experimental animal for cardiovascular investigations: stable recording of electrocardiogram of chick embryos in ovo on the 16th day of incubation.

Recording of electrocardiogram (ECG) tracings in developing chick embryos often fails because of spontaneous motion of the embryos in the egg shell. We attempted to record ECG of chick embryos in ovo. When we injected a mixture of 450 mg/ml urethane and 45 mg/ml alpha-chloralose into the air sac of fertile eggs at volumes of 0.1 to 0.3 ml, the spontaneous motor activity of chick embryos was decreased and stable ECG tracings could be obtained from at least 10 min after the injection. The P, QRS, and T waves were noted in the electrograms, and the QT interval was positively correlated to the RR interval. The heart rate (HR) could be analyzed for the RR interval in fertile eggs after the 8th day of incubation. The HR of the 16-day fertile embryos was linearly increased with incubation temperature in the range from 31 to 41 degrees C. Using this system, cardiac effects of some drugs were examined. Isoprenaline and acetylcholine increased and decreased the HR in a dose-dependent manner, respectively, and these effects were inhibited by respective antagonists, propranolol and atropine. These ECG responses of chick embryos were similar to those of mammals or humans. In conclusion, stable ECG tracings could be obtained from chick embryos anesthetized by urethane and alpha-chloralose in ovo and this method may be applicable for the investigation of the developing heart and the evaluation of cardiovascular drugs.

Age Factors↗

PubMed2006

Detection and enumeration of Salmonella enteritidis in homemade ice cream associated with an outbreak: comparison of conventional and real-time PCR methods.

Salmonellosis caused by Salmonella Enteritidis (SE) is a significant cause of foodborne illnesses in the United States. Consumption of undercooked eggs and egg-containing products has been the primary risk factor for the disease. The importance of the bacterial enumeration technique has been enormously stressed because of the quantitative risk analysis of SE in shell eggs. Traditional enumeration methods mainly depend on slow and tedious most-probable-number (MPN) methods. Therefore, specific, sensitive, and rapid methods for SE quantitation are needed to collect sufficient data for risk assessment and food safety policy development. We previously developed a real-time quantitative PCR assay for the direct detection and enumeration of SE and, in this study, applied it to naturally contaminated ice cream samples with and without enrichment. The detection limit of the real-time PCR assay was determined with artificially inoculated ice cream. When applied to the direct detection and quantification of SE in ice cream, the real-time PCR assay was as sensitive as the conventional plate count method in frequency of detection. However, populations of SE derived from real-time quantitative PCR were approximately 1 log higher than provided by MPN and CFU values obtained by conventional culture methods. The detection and enumeration of SE in naturally contaminated ice cream can be completed in 3 h by this real-time PCR method, whereas the cultural enrichment method requires 5 to 7 days. A commercial immunoassay for the specific detection of SE was also included in the study. The real-time PCR assay proved to be a valuable tool that may be useful to the food industry in monitoring its processes to improve product quality and safety.

Colony Count, Microbial↗

PubMed1990

[Establishment and characterization of a monoclonal antibody against egg antigens of Schistosoma japonicum].

A monoclonal antibody (N29B3) against egg antigens of Schistosoma japonicum was obtained by hybridoma technique N29B3 was of IgG3 isotype. The molecular weight of its target antigen was 141 KD. IIFA with section of liver from infected rabbit showed that N29B3 was located on surface of miracidium and egg shell. IIFA and ELISA also showed that N29B3 was not reactive with antigens of differential developmental stages of S. japonicum and antigens of other trematodes. The data indicated that N29B3 has specificity for egg antigens. In western blotting, sera from chronic infected human and mice and from acute infected mice (30 and 45 days) all recognized 141 KD molecule. These results suggest that 141 KD molecule has potential capacity for early diagnosis of schistosomiasis.

Animals↗

PubMed1998

Lesions caused by cardiovascular flukes (Digenea: Spirorchidae) in stranded green turtles (Chelonia mydas).

Evidence of infection with spirorchid flukes (Digenea: Spirorchidae) was sought at necropsy of 96 stranded green turtles, Chelonia mydas, that were examined during the course of a survey of marine turtle mortality in southeastern Queensland, Australia. Three species of spirorchid (Hapalotrema mehrai, H. postorchis, and Neospirorchis schistosomatoides) were identified. Severe disease due to spirorchid fluke infection (spirorchidiasis) was implicated as the principal cause of mortality in 10 turtles (10%), and appeared to be one of multiple severe problems in an additional 29 turtles (30%). Although flukes were observed in only 45% of stranded C. mydas in this study, presumed spirorchid fluke infection was diagnosed in an additional 53% of turtles, based principally on characteristic necropsy lesions and to a lesser extent on the histopathological detection of spirorchid eggs. Characteristic necropsy lesions included miliary spirorchid egg granulomas, which were observed most readily on serosal surfaces, particularly of the small intestine. Cardiovascular lesions included mural endocarditis, arteritis, and thrombosis, frequently accompanied by aneurysm formation. Resolution of thrombi was observed to occur via a combination of granuloma formation about indigestible components (spirorchid fluke egg shells) and exteriorization through the vessel wall, which resulted in granulomatous nodules on the adventitial surface. Septic aortic thrombosis complicated by disseminated bacterial infection, observed in five turtles, was recorded for the first time. Egg granulomas were ubiquitous in turtle tissues throughout this study. Although they generally appeared to be mild or incidental lesions, they were occasionally associated with severe multifocal granulomatous pneumonia or meningitis.

Animals↗

PubMed1991

Immunohistochemical localization of a calcium pump and calbindin-D28k in the oviduct of the laying hen.

The localization of a plasma membrane calcium pump in the oviduct of the laying hen was investigated by immunohistochemical techniques, utilizing a monoclonal antibody (5F10) produced against the human erythrocyte calcium pump. This antibody was shown to react with an epitope of the pump in oviductal tissue, and prominent staining was observed on the microvilli of the tubular gland cells of the hen shell gland (uterus) and the isthmus. The Ca2+ pump was not detectable in the infundibulum or the magnum. Calbindin-D28k, also localized by immunohistochemical means, was observed to be present in the tubular gland cells of the shell gland and the distal isthmus (adjacent to shell gland) but not in either the proximal isthmus (adjacent to the magnum), the magnum or the infundibulum. The localization of the Ca2+ pump in the oviduct corresponds to known sites of mineral deposition during egg shell formation. The distribution of calbindin-D28k differed, co-localizing with the Ca2+ pump in the shell gland and distal isthmus but not in the proximal isthmus. This might reflect a greater rate of active Ca2+ secretion in the distal isthmus and shell gland as compared to the proximal isthmus.

Animals↗

PubMed1981

[Peas (Pisum sativum L.) as a mixed feed component for laying hens].

Percentages of 0, 10, 20 and 30% peas (Pisum sativum) of the variety "Nadia" in the mixed feed with methionine supplementation were tested with 2,100 laying hybrids of the species White Leghorn in the age period between the 22nd and 73rd week of their lives which were kept in 3-storeyed cages. The feeding of peas had no influence on feed intake, laying performance, the weight of the individual egg, the stability of the egg shell, body weight, mortality, the hemoglobin content and the hematocrit value of the blood. With the increasing percentage of peas the consumption per animal and day and the expenditure of energy and methionine/cystine per 100 g egg decreased and that of lysine increased (p less than 0.05). On the basis of the investigations the conclusion is drawn that in laying hen feed supplemented with methionine a quota of up to 30% peas is possible without a decrease in performance.

Amino Acids↗

PubMed1984

Effect of the insect growth regulator CGA-72662 (Larvadex) on broiler breeder production, hatchability, and subsequent chick performance.

Broiler breeders were fed CGA -72662 ( Larvadex ) at dosages of 0, 30, 300, and 3000 mg/kg (ppm) diet in a standard breeder diet from 25 to 65 weeks of age. The 3000 ppm level was reduced stepwise to 1000 ppm from 25 to 27 weeks due to a significant increase in male and female mortality. Feed consumption did not differ significantly due to treatment. However, birds fed 300 ppm exhibited significantly improved feed conversion and increased egg production on a hen-day basis compared to those fed 0 and 30 ppm with the 1000 ppm level intermediate. On an egg per hen-housed basis, birds fed 300 ppm produced significantly more eggs than those fed 0 ppm with 30 ppm intermediate. Hens fed 1000 ppm produced significantly fewer eggs than all other treatments due to higher initial mortality. Body weight gains for males and females among treatments were similar. Mortality was significantly greater at 1000 ppm than for all other treatments. Egg specific gravity at 50 and 60 weeks was not affected significantly by any treatment. Egg weight, when compared to the 0 ppm level, was decreased significantly at the 1000 ppm level at 50 weeks and by both 300 and 1000 ppm levels at 60 weeks. Egg shell weight was not affected significantly at 50 weeks, but was decreased significantly by both 300 and 1000 ppm Larvadex at 60 weeks. There were no significant effects due to treatment level on fertility, early deads , pipped eggs, hatchability of fertile eggs, or hatchability of eggs set.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1980

Ultrastructure of vitelline membranes from normal and mottled egg yolks.

This study showed that ultrastructure of the vitelline membrane degenerated with degree of yolk mottling. The more severe the mottling the greater the damage to the membrane. The vitelline membrane appears to be composed of three separate structures. The primary matrix (probably collagen) retains its composition until mottling is most severe; then this structure starts to come apart and lose its integrity. The secondary matrix (probably mucin) aids in holding the primary structure in a fixed position. When this structure is removed there is movement in the primary matrix causing large holes to appear. The tertiary matrix (also mucin) is the quickest to disintegrate. The tertiary matrix covers the other structures much like the cuticle around the egg shell. Once it is removed, the remaining structures are open to stress and damage as mottling increases.

Animals↗

PubMed1984

Variations of titers of immunofluorescent antibody against cercaria, adult and egg antigens developed in rabbits infected with Schistosoma japonicum before and after treatment with praziquantel.

The antibody titers of Schistosoma japonicum infected rabbits were examined against different antigens in various stages of S. japonicum using the indirect immunofluorescent antibody test with FITC-labeled anti-rabbit-gamma-globulin. The first immunofluorescent reaction could be demonstrated in the gut of adult worms 3 to 4 weeks after infection, depending on the strength of infection, then 2 weeks later within the egg shell and on the cercaria and about 1 more week later in the tegument of adult schistosomes. Treatment with praziquantel resulted in a remarkable decrease of the titers with cercaria antigen and in only a gradual decrease with egg, tegument and gut antigen. Therefore cercaria antigen seemed to be the most reliable index of successful treatment. The high sensitivity of gut and egg antigen might lead to difficulties to distinguish the successfully treated cases from chronic cases of S. japonicum infections.

Animals↗

PubMed1993

Enterocyte expression of calbindin, calbindin mRNA and calcium transport increases in jejunal tissue during onset of egg production in the fowl (Gallus domesticus).

1. Quantitative measurements of calbindin mRNA, calbindin protein and calcium uptake have been made in sectioned intestinal villi to determine the location and cellular characteristics of their expression in immature, point of lay and laying chickens. 2. Trace amounts of calbindin mRNA were detected by in situ hybridization in enterocytes located around the crypt-villus junction in jejunal tissue taken from immature and point of lay chickens. Large amounts of calbindin mRNA were detected in upper crypt and all villus enterocytes in tissue taken from laying chickens. Maximal levels of calbindin mRNA occurred in the basal third of the villus in laying chickens. 3. No calbindin was detected immunocytochemically in tissue taken from immature and point of lay chickens. Large amounts of calbindin were expressed in tissue taken from laying chickens. Maximal expression of calbindin in this case occurred in villus tip enterocytes. 4. Rapid uptake of calcium by tissue taken from laying chickens was twice that found in immature and point of lay birds. Calcium uptake in tissue taken from laying hens was also shown by quantitative autoradiography to take place maximally in villus tip enterocytes. 5. Regulation of calbindin gene expression and the cellular characteristics of calcium transport in laying chickens are discussed in terms of an adaptive response taking place in birds undergoing a daily loss of egg shell calcium.

Aging↗

PubMed2006

Inactivation of single-celled Ascaris suum eggs by low-pressure UV radiation.

Intact and decorticated single-celled Ascaris suum eggs were exposed to UV radiation from low-pressure, germicidal lamps at fluences (doses) ranging from 0 to 8,000 J/m2 for intact eggs and from 0 to 500 J/m2 for decorticated eggs. With a UV fluence of 500 J/m2, 0.44-+/-0.20-log inactivation (mean+/-95% confidence interval) (63.7%) of intact eggs was observed, while a fluence of 4,000 J/m2 resulted in 2.23-+/-0.49-log inactivation (99.4%). (The maximum quantifiable inactivation was 2.5 log units.) Thus, according to the methods used here, Ascaris eggs are the most UV-resistant water-related pathogen identified to date. For the range of fluences recommended for disinfecting drinking water and wastewater (200 to 2,000 J/m2), from 0- to 1.5-log inactivation can be expected, although at typical fluences (less than 1,000 J/m2), the inactivation may be less than 1 log. When the eggs were decorticated (the outer egg shell layers were removed with sodium hypochlorite, leaving only the lipoprotein ascaroside layer) before exposure to UV, 1.80-+/-0.32-log reduction (98.4%) was achieved with a fluence of 500 J/m2, suggesting that the outer eggshell layers protected A. suum eggs from inactivation by UV radiation. This protection may have been due to UV absorption by proteins in the outer layers of the 3- to 4-microm-thick eggshell. Stirring alone (without UV exposure) also inactivated some of the Ascaris eggs (approximately 20% after 75 min), which complicated determination of the inactivation caused by UV radiation alone.

Animals↗

PubMed1977

Studies on the avian shell gland during egg formation: aqueous and electrolytic composition of the mucosa.

The intracellular composition of the avian shell gland mucosa was studied at six stages of egg formation. 2. Total water content of the mucosa before shell calcification was 4-8 kg/kg dry weight (dw) and rose to 6-6 kg/kg dw during shell formation; 60% of the increase was intracellular and 40% extracellular. 3. The potassium concentration of the mucosa remained constant during egg formation. 4. Chloride was removed constantly from the mucosal cells during egg formation. 5. A model was constructed for the glandular cells which depicts them as primarily NaHCO3-secreting cells towards the luminal side and HCl-secreting cells towards the serosal side, their main function being to provide CO2/3- for shell formation. In this model, the columnar mucosal cells are responsible for the calcium used in shell formation.

Animals↗

PubMed2001

Spatial distribution and hatching of overwintered eggs of a fish ectoparasite, Argulus coregoni (Crustacea: Branchiura).

The habitat distribution of overwintered eggs, which were found to be the only source of spring recruitment of Argulus coregoni Thorell, was studied at a commercial fish farm in Central Finland. The frequency of occurrence of egg clutches in the deep parts of the canals and ponds was 50 to 80% and the percentage cover of the surface of stones with egg clutches was 1.7 to 6.4%, while in the shallow parts these values were 8 to 27% and 0.1 to 0.3%, respectively. A greater proportion of empty egg-shells was observed in shallow water in the mid-May, suggesting an earlier hatching there stimulated by the increased temperature and higher illumination. Under laboratory conditions, only elevated UV illumination, but not diurnally fluctuating temperature, significantly accelerated hatching. Normally overwintered eggs produced a pronounced peak of hatched larvae at the end of May and hatching continued at a much slower rate throughout the summer. Eggs that overwintered twice, first normally and then for a second time buried under sediments, were exposed to the same laboratory conditions simultaneously with normally overwintered eggs, but their hatching was delayed until August. The hatching rate was low, but markedly increased in December.

Animals↗