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At least 649 records · Page 36Linked to original sources
PubMed1980

Classification of bacteria from commercial egg washers and washed and unwashed eggs.

A total of 432 bacterial isolates from washed and unwashed eggs, egg-washer surfaces, and washwaters from five egg-grading plants in Maryland and southeastern Pennsylvania were classified. Counts on equipment surfaces showed considerable variation from plant to plant, reflecting care used in cleaning. Unwashed eggs had a higher percentage of gram-positive cocci (71%), and isolates included Streptococcus faecalis, Aerococcus, and Escherichia coli, which were not isolated from equipment surfaces and washwaters. Equipment surfaces had a higher proportion of actinomycetes than unwashed eggs, and predominant gram-negative rods were Alcaligenes and Moraxella, which were not found on unwashed eggs. Flavobacterium and Alcaligenes have been implicated in shell egg rots, Staphylococcus aureus has been implicated in food poisoning, and organisms resembling micrococci and actinomycetes have been found in broken-out egg products.

Animals↗
PubMed1999

Abnormal zonae pellucidae in mice lacking ZP1 result in early embryonic loss.

All vertebrates have an egg shell that surrounds ovulated eggs and plays critical roles in gamete recognition. This extracellular matrix is known as the zona pellucida in eutherian mammals and consists of three glycoproteins, ZP1, ZP2 and ZP3 in the mouse. To investigate the role of ZP1 in fertilization and early development, we have used targeted mutagenesis in embryonic stem cells to create mouse lines (Zp1(tm/tm)) lacking ZP1. Although a zona pellucida composed of ZP2 and ZP3 was formed around growing Zp1(tm/tm) oocytes, the matrix was more loosely organized than zonae around normal oocytes. In some Zp1 null follicles, this structural abnormality resulted in ectopic clusters of granulosa cells, lodged between the zona matrix and the oolemma, that perturbed normal folliculogenesis. Comparable numbers of eggs were ovulated from Zp1 null females and normal females following hormonal stimulation. However, after mating with males, fewer two-cell embryos were recovered from Zp1 null females, and their litters were significantly smaller than those produced by normal mice. Therefore, although mouse ZP1 is not essential for sperm binding or fertilization, it is required for the structural integrity of the zona pellucida to minimize precocious hatching and reduced fecundity.

Animals↗
PubMed1992

[Prevention of salmonella infections in laying hens by vaccination].

After multiple infections with S. enteritidis in humans and demonstration of S. enteritidis in egg products, S. enteritidis (lysotype 6, plasmid profile 40) could be isolated from organs of hens, anal swab tests of chicken, liquid manure, egg shells and non pasteurized egg contents. Because of the largeness of the hen farm prophylactic vaccinations seemed to be advisable additionally to improvement of the management and hygiene. A vaccine registered in 1987 for use in pigeons and water fowl "Zoosal oral Dessau" was used. As a test three were vaccinated three times and artificially infected. Cross immunity against S. enteritidis could be demonstrated. In October 1987 all chicken of the farm were vaccinated three times at the age of 4, 6 and 7 weeks; random samples were tested for immunity and cross immunity. Until the end of the laying period immunity against S. typhimurium could be proven in 98% of the hens, against S. enteritidis in 95%.

Animals↗
PubMed1987

Lectin binding to the developing forms of Onchocerca gutturosa microfilariae.

Uterine and skin derived forms of microfilariae (mf) and earlier developing stages of the cattle filarial nematode Onchocerca gutturosa were examined for the lectin binding properties of their external surfaces (ie. egg shell and microfilarial cuticle). Both the uterine and skin derived forms of mf failed to bind any of the lectins tested. Incubation in known microfilaricides did not promote any binding of lectins to these parasites. Peanut agglutinin (PNA) was the only lectin found to bind specifically to earlier developing stages (i.e. the shells of freshly obtained eggs). Diethylcarbamazine (DEC) did not alter the binding pattern from that observed in untreated eggs. Ivermectin eliminated PNA binding but increased Ricinus communis lectin (RCA-1) positivity. Trypsin, collagenase and protease enzymes all affected the binding; chitinase however did not have any effect. These results support the concept that the eggshells of filariae can interact with the host defence responses.

Animals↗
PubMed1980

Ultrastructural morphology of the shell and shell membrane of eggs of common snapping turtles (Chelydra serpentina).

Common snapping turtles (Chelydra serpentina) lay nearly spherical, flexible-shelled eggs having an outer mineral layer composed of calcium carbonate in the aragonite form. The mineral layer is arranged into loosely organized groups of nodular shell units, with numerous spaces (or pores) between adjacent shell units. Shell units are structurally complex, consisting of an inner tip that is morphologically distinct from the main body of the shell unit. Contained within an intact shell unit at the interface of the tip and the main part of the shell unit is the central plaque, an apparent modification of the shell membrane that may serve to nucleate calcification of shell units during shell formation. The tips of shell units are firmly attached to a single, multilayered shell membrane throughout much of incubation. The calcareous layer begins to detach from the shell membrane about half-way through incubation, and changes in shell morphology attending this detachment indicate that snapping turtles may use the shell as a source of calcium during embryogenesis. The arrangement of the mineral layer into groups of shell units, the large number of spaces between shell units, and little or no interlocking of crystallites of adjacent shell units apparently are factors contributing to the ability of these eggs to swell as they absorb water.

Animals↗
PubMed1988

Significance of growing photoperiod and light stimulation at various ages for Leghorn pullets subjected to regular or ahemeral photoperiods.

Leghorn pullets were cage reared to 15 or 19 wk of age in environmentally controlled rooms that provided either 8 h or 14 h of light per day. In Experiment 1, birds were moved to laying cages at 15 wk of age and subjected to either 14 h light (L): 10 h (D) dark or ahemeral 14L:14D photoperiods. Feed intake, egg weight, shell quality, and egg production were monitored to 67 wk of age. In Experiment 2, pullets were moved at 19 wk of age and subjected to 14L:10D or 17L:7D light programs. Production parameters were measured as previously described. No significant (P greater than 0.5) interactions were observed between rearing and laying photoperiods, suggesting that increase in the length of photoperiod around time of maturity is not essential for adequate performance. In Experiment 1, ahemeral lighting resulting in reduced egg production, whereas egg shell quality and egg weight were improved (P less than .05). In both experiments, the 14-h rearing program resulted in improved egg size together with improved eggshell quality (P less than .05). Whereas increased egg size may relate to body weight, no explanation is apparent for the consistent pattern with respect to shell quality. In Experiment 2, poorer shell quality was observed with 17 vs. 14 h light per day. It is concluded that light stimulation at maturity has little effect on overall egg production. Improved shell quality observed with birds reared under 14 h light vs. those reared under 8 h per day may relate to a less rapid attainment of peak egg production.

Aging↗
PubMed1986

Properties and localization of chitin synthase in Ascaris suum eggs.

Investigations were carried out into the properties and localization of chitin synthase (EC 2.4.1.16) in connection with the formation of Ascaris suum egg-shells. The chitin synthase of eggs exhibited properties very similar to those found in other chitin-synthesizing organisms. It was stimulated by the presence of ATP, GlcNAc and Mg2+ with maximal activity at pH 7.0. In the phase of active chitin synthesis, during formation of the primary shell layers, chitin synthase was bound to the structures of the eggs. On completion of chitin synthesis in the eggs, the amount of the enzyme increased in the soluble fraction. Two forms of chitin synthase have been found in the eggs, namely an inactive (zymogenic) and an active form. Transformation of these two enzyme forms represents a key mechanism in the regulation of chitin synthesis in A. suum eggs.

Adenosine Triphosphate↗
PubMed2003

Investigations into possible alternative decontamination methods for Salmonella enteritidis on the surface of table eggs.

Investigations into various alternative techniques for decontamination of the surfaces of artificially contaminated shell eggs were carried out. Ionized air, exposure to ozone in a dry atmosphere and use of a commercial herbal antibacterial product were not effective. Application of ozone in a humid environment was only partially effective but a commercial ionized water anolyte was highly effective in eliminating Salmonella from egg surfaces.

Animals↗
PubMed2002

Fatty acid composition and egg components of specialty eggs.

Egg components, total fat, and fatty acid content of specialty eggs were compared. One dozen eggs were collected and analyzed from each of five different brands from hens fed a diet free of animal fat (SP1), certified organic free-range brown eggs (SP2), uncaged unmedicated brown eggs (SP3), cage-free vegetarian diet brown eggs (SP4), or naturally nested uncaged (SP5). Regular white-shelled eggs were the control. A significant (P < 0.05) difference was observed in the egg components and fatty acid content in different brands. The percentage of yolk was lower (P < 0.05) in SP2 and SP4 with a concomitant increase (P < 0.05) in the percentage of white. The percentage of shell was lower (P < 0.05) in SP4 and SP5. The total edible portion was greater in SP4 and SP5. The yolk:white ratio was greater (P < 0.05) in SP3. The total lipid content was lower in SP4 eggs. The content of palmitic (C16:0), stearic (C18:0), and total saturated fatty acids were lower (P < 0.05) in SP1. No difference was observed in the content of palmitoleic (C16:1), oleic (C18:1), or total monounsaturated fatty acids. The content of n-3 fatty acids in SP2, SP4, and SP5 were similar to control eggs. The ratio of total n-6:n-3 polyunsaturated fatty acids ranged from 39.2 for SP5 to 11.5 for SP1 (P < 0.05). No difference was observed in the total polyunsaturated fatty acid content of eggs (P > 0.05).

Animal Feed↗
PubMed1991

Isolation and identification of adenovirus 127, the causative agent of egg drop syndrome (EDS), from commercial laying hens in South Africa.

A drop in egg production associated with loss of pigment and soft-shelled eggs was experienced on a farm in the Western Cape. Investigations revealed high levels of antibodies against adenovirus 127, the causative agent of egg drop syndrome (EDS) in chickens which were not vaccinated against EDS. A cytopathic agent was subsequently isolated in chicken embryo liver cell cultures and identified as EDS virus by haemagglutination inhibition and neutralization tests.

Adenoviridae Infections↗
PubMed1983

Novel amplification and transcriptional activity of chorion genes in Drosophila melanogaster follicle cells.

Single-copy chorion genes coding for egg shell proteins are amplified in the follicle cells of Drosophila melanogaster egg chambers. Chromatin spreads of appropriately staged follicle cells reveal complex, multi-forked chromosomal structures in which one chromatin strand branches into two, which themselves branch out, and so on. In one micrograph, 13 strands originating from a single strand were observed. These structures can account for the maximal amplification occurring in the center of the domain, where the major chorion genes are located, and the decreasing amplification of flanking sequences to both sides. The amplification, high transcriptional rate, stage-specific expression, and correlation with known molecular sizes have allowed the putative identification of the single-copy, major chorion genes on the X chromosome and on chromosome III.

Animals↗
PubMedDate not supplied

Ruptured-yolk peritonitis and organochlorine residues in a royal tern.

Ruptured-yolk peritonitis was responsible for the death of a royal tern. Lodgment of eggs in the oviduct was probably due to reverse peristalsis brought about by breakage of the thin-shelled eggs and secondary bacterial infection. The thin shells were apparently not related to the low levels of DDE and other organochlorine pollutants found in tissues and egg contents.

Animals↗
PubMed1984

Increasing hatchability of turkey eggs by matching incubator humidity to shell conductance of individual eggs.

One of the most important factors determining hatchability of avian eggs is the proper water balance of the eggs during incubation. In turkey eggs, a total diffusive water loss (F) of 12 +/- 1% SD initial egg mass in 28 days, yielded maximal hatchability irrespective of the combination of eggshell water vapor conductance (G) and incubator humidity (PI), which brought about this water loss. A good correlation was found between G as obtained at the beginning of incubation and the final F in a given PI. The G in a random sample of 1256 fresh turkey eggs was normally distributed around the mean of 18.70 +/- 2.87 SD milligrams (100 g X day X torr)-1 (Coefficient of variation = 15.3%). The distribution of G in eggs with dead in the shell embryos had, in addition, two more peaks of G values [around 22.5 and 13.0 mg (100 g X day X torr)-1]. When eggs were sorted into low (less than 17), medium (17 to 20), and high (greater than 20) G categories, and incubated at low (19.4), medium (26.6), and high (33.9) torr PI, respectively, hatchability increased by a factor of 1.08. Poor hatchabilities were obtained in mismatching humidities and conductances. It seems that hatchability success may be experimentally improved if a correct rate of water loss is fitted to sorted eggs during incubation.

Animals↗
PubMed1993

Hatching failure in common terns (Sterna hirundo) in relation to environmental chemicals.

The hatching success of two Common Tern colonies, a highly contaminated one at the Elbe estuary (Hullen) and a less contaminated one at the Jade (Augustgroden, southern North Sea coast, Germany), was similar in 1988; 69% at Hullen and 73% at Augustgroden. Most egg loss was due to predators. The number of eggs failing to hatch from unknown causes was 6.3% higher at Hullen than at Augustgroden. Egg-shell thickness and strength were not correlated with the chemicals' concentrations. At Hullen unhatched eggs were compared with randomly collected fresh eggs; the former containing a significantly higher amount (20%) of PCBs (134 microg) than the eggs collected at random (112 microg). Seven out of 45 PCB-congeners were found in significantly higher amounts in the failed eggs, among them the toxic congener PCB 138. The two samples showed no difference in mercury concentration, which was 6.2 mg kg(-1), nor difference in shell strength. Eggs of Common Terns breeding at the Elbe estuary had concentrations of some contaminants reaching levels endangering breeding success.

Journal Article↗
PubMed1984

Response of different commercial strains of laying hens to short total photoperiods in interrupted night experiments during days of 24 and 28 hours.

Experiments were conducted: as pilot experiments in which each experimental unit, replicated two or three times, consisted of 15 hens, as practical experiments in which each of four strains was replicated twice in two rooms containing 200 to 265 hens, and as commercial experiments in which each experimental unit consisted of 4 strains of 1000 hens but in which no replication occurred. Short total photoperiods were used in interrupted night experiments with 24-hr and 28-hr days. A light regimen of 2L:6D:2L:18D yielded similar results as 12L:16D for percent egg production, egg mass, egg shell breaking strength, and feed efficiency. Exposure to 28-hr days, in comparison with 24-hr days, resulted in a reduction of number of eggs produced but did not reduce egg mass produced. In one of four strains, the increase in egg size and reduction in number of eggs produced was significantly (P less than .05) less than in the other three strains, Under the 28-hr day regimens shell breaking strength was consistently greater (P less than .01) than under 24-hr light regimens. In an additional experiment, no relationship was found in egg breakage during transport between two populations of eggs that differed in eggshell breaking strength as a result of differences in light regimens received by the hens. Short (2L:10D:2L:10D or 2L:12D:2L:8D) and very short (2L:12D:1/4L:9 3/4D) interrupted night regimens generally yielded lower egg production than 16L:8D or 8L:10D:2L:4D light regimens. There was an indication that there might be strain differences in the response to the interrupted night regimen. Exposure to 2L:6D:2L:8D for 6 weeks at the start and 8 weeks at the end of an 11-month experimental period, with 16L:8D given during the remainder of the period, resulted in lower egg production during the last 8 weeks and no compensatory improvement in egg shell breaking strength or egg weight in comparison with continuous exposure to 16L:8D.

Animals↗