SEARCH · PubMed Health

Results for “Egg Shell”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

PubMed1990

Plasma calcitriol in chickens producing strong and weak egg shells and the response of hens to exogenous calcitriol.

Calcitriol (CAL) regulates intestinal calcium transport by inducing an increase in membrane phosphatidylcholine (PC) and calbindin. A positive correlation has been reported between shell gland PC and egg shell strength. Three experiments were conducted to test the hypothesis that the improvement in egg shell strength associated with increased PC is mediated via changes in the concentration of CAL. Sera from aged laying hens, identified as either strong (SES) or weak (WES) egg shell producers, were obtained from blood samples collected at 16 h after oviposition and assayed for CAL. Laying hens were injected (i/m) with 1.0 or 0.4 micrograms CAL/d for 28 d. Serum CAL in the WES hens was 70% of that in the SES hens (P less than .05). Hens producing extremely weak shells did not respond to 0.4 micrograms CAL/d for 10 d. Administration of CAL did not improve egg shell strength nor was serum CAL increased when WES hens were molted and shell gland PC increased. The results show that serum CAL is lower in aged hens producing weak egg shells but shell strength is not responsive to exogenous CAL and increased shell gland PC in WES hens after molting is not associated with higher serum CAL.

Animal Nutritional Physiological Phenomena↗

PubMed2001

Dietary phosphorus supply, egg-shell deposition and plasma inorganic phosphorus in laying hens.

1. In 2 experiments the effects of dietary phosphorus on relationships between plasma inorganic phosphorus concentration (Pi), shell and egg production and depletion states were measured in brown laying hens. 2. In a 12-week experiment dietary phosphorus concentrations from conventionally deficient (1.6 g non-phytate-phosphorus (PNP)/kg) to moderate excess (3.9 g PNP/kg) had little effect on egg and shell production, although there was evidence that plasma Pi concentration, when not influenced strongly by shell formation, reflected dietary phosphorus content. 3. Among birds at each dietary phosphorus concentration there was a negative linear relationship between shell weight of early eggs in the sequence and plasma Pi concentration. The relationship was apparently not affected by dietary phosphorus concentration. 4. Continued feeding of the deficient diet to 61 weeks of age did not have effects on body weight, egg and shell production, other than those associated with age, but plasma Pi and bone measurements indicated marginal phosphorus depletion. 5. In another experiment excessive dietary phosphorus (11.9 g PNP/kg) fed in a cross-over design caused small adverse effects on shell production, increased food intake and body weight and increased plasma Pi content, while there was no relationship between shell weight and plasma Pi concentration. 6. The results are consistent with an indirect effect of plasma phosphorus accumulation on shell formation, probably via an inhibitory effect on skeletal calcium release, in addition to any effect of excess dietary phosphorus on intestinal calcium availability. 7. Phosphorus requirement and status in the laying hen are complicated by the failure to recognise the contribution of digestible phytate-phosphorus to the available phosphorus supply.

Animal Feed↗

PubMed2005

[Allergenic activity of non-calcinated egg shell calcium].

BACKGROUND: There is few data to prove the safety of egg shell calcium as allergen. Especially, non-calcinated egg shell calcium is not allowed to use without the description of origin of egg on food labels in Japan. METHOD: We evaluated the possibly contaminated egg allergens in commercial non-calcinated egg shell calcium made from egg by in vitro methodologies (SDS-PAGE, western blotting, inhibition ELISA and sandwich ELISA) and by single-blind oral non-calcinated egg shell calcium challenge on 6 egg hypersensitivity patients. RESULTS: The allergenic activity of non-calcinated egg shell calcium was almost negligible compared to egg white by all in vitro methods. Furthermore, six patients with egg hypersensitivity were unresponsive to oral non-calcinated egg shell calcium challenge test. CONCLUSION: These results indicate that there is little contamination of egg white in non-calcinated egg shell calcium, and that the allergenic activity of non-calcinated egg shell calcium is equivalent to that of calcinated egg shell calcium.

Allergens↗

PubMed1986

Effects of feeding graded levels of vitamin D3 on egg shell pimpling in aged hens.

Pimpled egg shells are one of the various types of egg shell problems in the industry today. In this study, graded levels of vitamin D3 (D3) (0, 138, 275, 550, 2200, 22,000, 44,000, and 88,000 ICU of D3/kg of feed) were fed in a corn-soy ration to Single Comb White Leghorn hens (78 weeks of age), randomly assigned to one of the eight treatments. Feed consumption, egg production, egg weight, egg specific gravity, and pimple score were determined at weekly or biweekly intervals for a 10-week period. At termination of the experiment, calcium, sodium, potassium, and ash content of the uterus and serum calcium levels were assayed. Results showed that a significant (P less than .05) linear increase in pimple score, uterine ash, and serum calcium occurred as dietary levels of D3 increased. Egg production and egg specific gravity were correlated to D3 level in a quadratic fashion. Uterine sodium levels declined with increased D3 in the diet, while potassium values showed no differences. Calcium levels of uterine tissue tended to increase with increased D3. The lowest (0 ICU/kg) and highest level of D3 (88,000 ICU/kg) significantly decreased feed consumption. It was concluded that egg shell pimpling is directly related to level of cholecalciferol (D3) in the diet.

Aging↗

PubMed1976

Egg-shell formation in Isoparorchis hypselobagri.

Egg-shell formation in Isoparorchis hypselobagri is descirbed. The egg-shell in Isoparorchis hypselobagri is colorless and transparent as in case of Diplodiscus mehrai (Madhavi, 1968). Eleven histochemical tests were used to elucidate the process and it was observed that the basic mechanism of egg-shell formation followed the quinone tanned system as all the three precursors i.e. proteins, phenols and phenolase were present in vitelline globules.

Animals↗

PubMed1982

Effect of p-p'-DDE administered in vivo and in vitro on Ca2+ binding and Ca2+-Mg2+-ATPase activity in egg shell gland mucose of ducks.

Thinning of the egg shell is produced by p-p'-DDT and DDE in several species of birds. A study was made of the effect of DDE administered in vitro and in vivo on the Ca2+ binding and Ca2+-Mg2+-activated ATPase of a homogenate of the egg shell gland of ducks (Anas platyrhynchos var.). The concentration of Ca2+ was 1 X 10(-4) M and that of MgATP 1 X 10(-3) M. In vitro, DDE in concentrations of 2-16 micrograms/ml of incubation medium inhibited the Ca2+-Mg2+-activated ATPase in a concentration-dependent manner, whereas Mg2+-activated ATPase was not affected by these concentrations. The Ca2+ binding by the homogenate was reduced by DDE in the same concentrations. The sodium azide sensitive Ca2+ binding was most sensitive. In vivo, DDE administered in a concentration of 40 mg/kg dry weight of the food for 45 days reduced the egg shell index by 18% in comparison to controls. After 45 days of treatment the DDE concentrations in the egg shell gland mucosa was 1.20 +/- 0.16 micrograms/g of wet weight, while no DDE was detected in the controls. The Ca2+-Mg2+-activated ATPase was reduced by 32%, whereas the Mg2+-ATPase was not changed. The Ca2+ binding by the homogenate was reduced by 29%, the sodium azide sensitive part being most vulnerable, DDE increased the total Ca content of the egg shell gland mucosa by 44%. Since Ca is transported against a concentration gradient between blood plasma, and the lumen of the shell gland, it is suggested that DDE, by inhibiting the Ca2+-Mg2+-activated ATPase, decreased the Ca translocation over the egg shell gland mucosa.

Animals↗

PubMed2001

Response of foodborne Salmonella spp. marker strains inoculated on egg shell surfaces to disinfectants in a commercial egg washer.

The objective of this study was to determine the effectiveness of an iodine based disinfectant (IBD, Iocide, Biomedical Development Corporation, San Antonio, TX) on Salmonella enteritidis and S. typhimurium inoculated on egg shell surfaces under simulated industry egg processing conditions with a commercial egg washer used as the sanitizer delivery system. Re-circulated egg washer water containing 1.40-2.85 g/l total dissolved solids was obtained from a commercial egg processing. Sanitizing treatments consisted of distilled deionized water (DDW), IBD, and chlorine (CL; 200 ppm). All treatments (DDW, IBD and CL) significantly (p < 0.05) decreased Salmonella spp. populations on the shell compared to dry (no spray) egg controls. However, efficacy of egg sanitizers appeared to be dependent on the level of total dissolved solids in the egg wash water.

Animals↗

PubMed1976

[Penetration of Staphylococci through the egg-shell].

Penetration of staphylococci through egg-shell structures into the egg content was studied in 490 eggs. A series of experiments proved that staphylococci were able to penetrate through all egg-shell structures in a short time (of 1 hour) after the contamination. According to the results of these experiments, penetration was affected by the presence of cuticle, different shell porosity and high pH of the egg white.

Animals↗

PubMed1967

The chemical composition of the egg shells of the potato cyst-nematode, Heterodera rostochiensis Woll.

1. Eggs of the potato cyst-nematode (Heterodera rostochiensis Woll.) were isolated by sieving a suspension of crushed cysts. Eggs were broken open by ultrasonic vibration and the egg shells separated from the released larvae by centrifuging in a potassium tartrate density gradient. About 1 mg. of dried egg shells was obtained from 1000 cysts. 2. The major constituent of the egg shells was protein (59%, calculated from nitrogen content). About 80% of the egg shells went into solution on acid hydrolysis. Of the 18 amino acids determined with the Technicon Auto-Analyser, proline was most abundant and, with aspartic acid, glycine and serine, made up about 64% by weight of the total amino acids. The small amounts of aromatic and sulphur-containing amino acids, and the presence of hydroxy-proline, indicate a collagen-like protein. 3. The egg shells gave a positive van Wisselingh colour test for chitin, and glucosamine was detected in their acid hydrolysate by chromatography. The glucosamine content of the egg shells, determined by the Elson-Morgan colorimetric method, was 7%, corresponding to about 9% chitin. 4. Dried egg shells contained about 7% of lipid, 6% of carbohydrate and 3% of ash. Polyphenols (3% by weight of the egg shells) were detected in the acid hydrolysates. 5. Neither the collagen nor the chitin showed evidence of crystallinity when examined by X-ray diffraction.

Amino Acids↗

PubMed2003

4,4'-Dinitrocarbanilide (DNC) concentrations in egg shells as a predictor of nicarbazin consumption and DNC dose in goose eggs.

Nicarbazin is being investigated as an infertility agent for the control of non-migratory Canada geese (Branta canadensis L) populations. Nicarbazin is presently registered for use as a coccidiostat for poultry. Geese fed sufficient quantities of nicarbazin will lay non-viable eggs. We established nicarbazin consumption by measuring the concentration of a component of the formulation, 4,4'-dinitrocarbanilide (DNC) in the egg contents (yolk, albumin) in non-viable eggs. To estimate the nicarbazin consumption of birds that laid viable eggs (eggs that hatched or contained an embryo), a high-performance liquid chromatography method was developed to measure the concentration of DNC in egg shells. A statistically significant correlation was established using linear regression between the mean concentrations of DNC in the egg shell and in the egg contents in non-viable eggs. Viable eggs were estimated to contain lower levels of DNC than non-viable eggs. DNC concentrations in both the egg contents and the egg shell increased with increases in nicarbazin dose in feed. Our method allows for the estimation of nicarbazin consumption and DNC dose in eggs under field conditions, which is important in developing an effective infertility agent for over-abundant non-migratory goose populations.

Animal Feed↗

PubMed2002

The origin of lactation as a water source for parchment-shelled eggs.

Available evidence indicates that mammary gland secretions first evolved in synapsids that laid parchment-shelled eggs. Unlike the rigid-shelled eggs of birds and some other sauropsids, parchment-shelled eggs lose water very rapidly when exposed to ambient air of lower vapor pressure, whether due to differences in relative humidity or to differences in temperature. This precludes endothermic incubation of parchment-shelled eggs in an open nest. Synapsids may have avoided egg desiccation by incubating eggs in a pouch, but this would limit maternal activity. Parchment-shelled eggs are able to take up liquid water across the eggshell. I propose that mammary secretion originally evolved as a means of supplying water to eggs, and as such was essential to the evolution of endothermy among the egg-laying cynodonts that were ancestral to mammals. It is possible that synapsid eggs, like parchment-shelled squamate eggs, were also capable of uptake of some nutrients, such as sodium and ionic calcium. Living monotremes still produce parchment-shelled eggs. The porous eggshell and bilaminar yolk sac membrane of these eggs permit substantial uptake of uterine secretions during the intrauterine period, and might also facilitate uptake of mammary secretions during egg incubation. In its simplest form, mammary secretion may be an ancient trait of egg-laying synapsids, having had an important role long before milk became obligatory for suckling young.

Animals↗

PubMed1990

Shell gland adenosine triphosphatase in hens producing strong and weak egg shells.

1. Two groups of 4 hens at the end of their first production cycle were classified as producers of strong egg shells (greater than 70 mg/cm2) and weak egg shells (less than 60 mg/cm2) on the basis of shell surface density. 2. Shell gland mucosa was homogenised and fractionated into nuclear, mitochondrial, microsomal and supernatant fractions, and ATPase activity determined. 3. ATPase activity in the total homogenate was significantly greater for hens producing strong shells (SES) than for hens producing weak shells (WES). 4. ATPase activities detected in the nuclear fraction, mitochondria and microsomes were significantly greater for SES than for WES birds.

Adenosine Triphosphatases↗

PubMed2005

Inactivation of Salmonella enterica serovar Enteritidis on shell eggs by ozone and UV radiation.

The presence of Salmonella enterica serovar Enteritidis in shell eggs has serious public health implications. Several treatments have been developed to control Salmonella on eggs with mixed results. Currently, there is a need for time-saving, economical, and effective egg sanitization treatments. In this study, shell eggs externally contaminated with Salmonella (8.0 x 10(5) to 4.0 x 10(6) CFU/g of eggshell) were treated with gaseous ozone (O3) at 0 to 15 lb/in2 gauge for 0 to 20 min. In other experiments, contaminated shell eggs were exposed to UV radiation at 100 to 2,500 microW/cm2 for 0 to 5 min. Treatment combination included exposing contaminated eggs to UV (1,500 to 2,500 microW/cm2) for 1 min, followed by ozone at 5 lb/in2 gauge for 1 min. Eggs that were (i) noncontaminated and untreated, (ii) contaminated and untreated, and (iii) contaminated and treated with air were used as controls. Results indicated that treating shell eggs with ozone or UV, separately or in combination, significantly (P < 0.05) reduced Salmonella on shell eggs. For example, contaminated eggs treated with ozone at 4 to 8 degrees C and 15 lb/in2 gauge for 10 min or with UV (1,500 to 2,500 microW/cm2) at 22 to 25 degrees C for 5 min produced 5.9- or 4.3-log microbial reductions or more, respectively, when compared with contaminated untreated controls. Combinations including UV followed by ozone treatment resulted in synergistic inactivation of Salmonella by 4.6 log units or more in about 2 min of total treatment time. Salmonella was effectively inactivated on shell eggs in a short time and at low temperature with the use of a combination of UV radiation and ozone.

Animals↗

PubMed2004

Cestrum diurnum leaf as a source of 1,25(OH)2 Vitamin D3 improves egg shell thickness.

A continuing concern of the poultry industry is the high incidence (12%) of egg losses in the laying house due to poor egg shell quality. Calcium (Ca) homeostasis is a key factor in egg shell formation. The economy of Ca utilisation is under the control of Vitamin D(3), particularly its active metabolite 1,25-dihydroxy cholecalciferol [1,25(OH)(2)D(3)]. Supplementation of 1,25(OH)(2)D(3) has been shown to increase specific gravity, shell thickness and shell weight of the egg. However, commercially available synthetic 1,25(OH)(2)D(3) is very expensive. Earlier studies from our Institute [Phytochemistry 37 (1994) 677] have identified a cheap, natural and rich source of 1,25(OH)(2)D(3) in the leaves of Cestrum diurnum (CD), a member of the Solanaceae family. In this study, CD leaves were explored as a source of 1,25(OH)(2)D(3) in the feed of layer birds to improve the egg shell thickness. Fifteen-week-old white leghorn layers were divided into four treatments of 60 birds each and as follows: (I) normal diet with Vitamin D(3), (II) normal diet with Vitamin D(3) + CD, (III) normal diet without Vitamin D(3) and, (IV) normal diet without Vitamin D(3) + CD powder. CD leaf powder was incorporated in to the feed at 0.3% level. The experimental feeding was continued up to 72 weeks of age of the birds. Weekly food intake and daily egg production were noted throughout the experimental period and the specific gravity of the eggs, feed consumed to lay one egg and egg shell thickness were determined. Incorporation of CD leaves in the feed had the maximal effect on all the parameters studied. The feed consumed to lay one egg was 20 g less than the control group. The specific gravity of the egg was higher by 0.005, than the control egg, indicating a 5% decrease in the breakage of eggs in CD fed chicks. Also there was a significant increase (P < 0.001) in egg shell thickness. The data suggest that incorporation of CD leaf powder in the feed of poultry layers increased the egg shell thickness, which in turn could decrease the economic loss due to breakage of eggs.

Animals↗

PubMed1994

Partial characterization of the protein and carbohydrate constituents of the egg shell of Hymenolepis diminuta (Cestoda).

The egg shell of Hymenolepis diminuta is composed of 31.7% protein and 2.9% carbohydrate (by weight), as determined using the Lowry and phenol-sulfuric acid assays and bovine serum albumin and glucose, respectively, as standards. Amino acid analyses of egg shells demonstrated the presence of 16 naturally occurring amino acids and six unidentified residues. Histidine accounted for > 22% of the amino acid residues. Hypochlorite-solubilized egg shells were fractionated using a combination of gel, hydroxyapatite and anion-exchange chromatography, and the fractions were analyzed by isoelectric focusing and gel chromatography. The results demonstrate that the shell consists of a complex mixture of proteins (almost all of which have acidic isoelectric points), glycoproteins and possibly free complex carbohydrates.

Amino Acids↗

PubMed1999

Packaging effects on shell egg breakage rates during simulated transportation.

Shell eggs were packaged in either expanded polystyrene (EPS) foam or molded paper pulp (MPP) one dozen cartons, then were bulk packaged in either polypropylene crates or corrugated boxes. The packages were then subjected to a well-defined computer-simulated vibration test on an electrohydraulic test machine. The percentage and the location on the egg (side, top, bottom) of breakage was determined in the secondary (corrugated box or polypropylene crate) and primary (EPS or MPP carton) package after 15, 75, and 180 min. For each of three trials, 60 dozen Grade A large eggs were randomly assigned to each primary package and cross-stacked in a secondary container that contained three cartons in a row and a total of five layers. When cartons were packed in 15-dozen corrugated boxes, no significant difference was found in total eggshell damage rates between the MPP carton and the EPS carton. However, when eggs were packed in 15-dozen plastic crates, the MPP cartons caused significantly less eggshell damage than the EPS cartons. The EPS cartons packed in corrugated boxes had the lowest breakage (4.63%), whereas the EPS foam cartons packed in plastic crates had the highest breakage (12.59%). When the effect of secondary packaging and vibration time were not considered, no significant difference was found between MPP and EPS cartons. In addition, when the effect of primary packaging was not taken into account, the corrugated boxes had significantly lower breakage rates than the plastic crates. Nearly 55% of the breakage occurred in the bottom section of the eggshell as compared to the side and top. When the test periods were compared, the EPS cartons packed in plastic crates had the highest breakage (16.28%) at 180 min.

Animals↗

PubMed2000

Salmonella penetration of egg shells and proliferation in broiler hatching eggs--a review.

The presence of salmonellae in fertile broiler hatching eggs has been clearly identified as a critical control point in the salmonellae contamination of broiler chickens. This paper reviews the published research studies on a) the penetration and proliferation of salmonellae in hatching eggs, b) the consequences of this contamination on the contamination of the final product, and c) the egg's defenses against invading salmonellae. A better understanding of the material in this review paper will assist poultry researchers and the poultry industry in continuing to make progress in reducing and eliminating salmonellae from fertile hatching eggs, hatcheries, and breeder flocks.

Animals↗

PubMed1982

A study of ultrastructure of egg shell of Schistosoma japonicum. I. Transmission electron microscopic observation of S. japonicum egg.

Ultrathin sections of egg shell of S. Japonicum were observed. The micropores and network of microcanals were first reported in egg shell of S. japonicum. Both the micropores and microcanals are lined by a membrane being continous with the inner layer of egg shell and filled with materials coming from inside of the egg. As in the egg of S. mansoni, the possibility of micropores and microcanals that may play an important role as natural channels in secreting materials such as soluble antigens and histolytic enzymes... etc., is discussed.

Animals↗