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At least 91 records · Page 5Linked to original sources
PubMed1992

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.

Animal Nutritional Physiological Phenomena↗
PubMed1976

The isolation and characterisation of hyaluronic acid in egg shell.

Analysis showed that the organic part of the chicken's egg shell consisted of a series of proteins and polysaccharides, probably present as glycoproteins and glycosaminoglycans. A purified preparation of a glycosaminoglycan (minimum mol. wt. 25 000), homogeneous by sedimentation velocity analysis and sedimentation to equilibrium in a density gradient, contained equimolar amounts of N-acetylglucosamine (36.3% s/w) and glucuronic acid 35.6% w/w). Digestion with testicular and streptomyces hyaluronidases and identification of the degradation products showed the glycosaminoglycan to be hyaluronidases and identification of the degradation products showed the glycosaminoglycan to be hyaluronic acid.

Acetylglucosamine↗
PubMed1996

Selection for egg shell strength in laying hens using shell membrane characteristics.

1. Divergent selection for attachment strength between the shell membrane and the calcium shell was performed in a White Leghorn strain. Multivariate analysis was used to estimate genetic parameters for shell membrane measurements and shell thickness. The aim was to investigate the possibility of improving shell strength in laying hens by selecting for increased attachment strength. 2. A significant direct selection response for attachment strength was achieved. There was a favourable correlated selection differential in the frequency of cracked eggs which resulted in a nonsignificant but favourable, correlated response. Selection for a strong attachment resulted in a thinner egg shell, and vice versa. Heritabilities were all relatively high (0.30 to 0.70). Most of the genetic correlations were in agreement with the achieved correlated responses. 3. Two factors that probably contributed to the responses in egg shell thickness were an unfavourable genetic correlation between attachment strength and shell thickness, and natural selection against changes in attachment strength, in the form of increased mortality during incubation and hatching. Problems connected with breeding for increased shell strength are discussed.

Animals↗
PubMed1977

A nutrient re-evaluation of shell eggs.

Most data on the nutrient composition of shell eggs were obtained before 1950. Since then, management systems for egg production and analytical methods for many components have changed. Freeze-dried whole egg, yolk and white samples were prepared from eggs obtained from a single source of 15 month old White Leghorns. The sample were packaged under nitrogen and held at -20 degrees C. until analyzed. Conversion factors are included for expressing the amount of each component on a per egg as well as a per 100 g. edible liquid basis. This re-evaluation of nutrient data included total solids, lipid, protein, cholesterol, ash, calories, amino acids, fatty acids, vitamins and minerals.

Amino Acids↗
PubMed1991

Modulation of quail intestinal and egg shell gland calbindin (Mr 28,000) gene expression by vitamin D3, 1,25-dihydroxyvitamin D3 and egg laying.

The effects of vitamin D3 sources, egg production and egg cycle on the genomic expression of calbindin (Mr 28,000) in the intestine and egg shell gland (ESG) of quail were characterized by Northern blot and solution hybridization, using synthetic oligonucleotide probe. In vitamin D3- or 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3)-fed quail, onset of egg production induced duodenal and ESG calbindin mRNA and calbindin synthesis. Duodenal calbindin mRNA was slightly higher during the period of shell calcification as compared with the period during which shells were not formed (ESG inactivity). ESG calbindin mRNA was markedly higher during the period of shell calcification than of ESG inactivity. Increasing dietary intake of [3H]1 alpha-hydroxyvitamin D3 increased the duodenal, but not ESG, content of 1,25-(OH)2D3 and calbindin. Duodenal calbindin and its mRNA were absent in vitamin D-deficient quail and were not affected by egg laying. ESG calbindin in the vitamin D-deficient quail was not affected by egg laying, but calbindin mRNA increased in the vitamin D-deficient birds during shell calcification. The results suggest that: (a) intestinal calbindin mRNA and calbindin are induced and/or regulated, either directly or indirectly, by 1,25-(OH)2D3; (b) intestinal calbindin and its mRNA are further induced at the onset of egg laying by an additional stimulator besides 1,25-(OH)2D3; (c) 1,25-(OH)2D3 is required for the expression of the latter stimulator; (d) ESG calbindin mRNA and calbindin are induced in egg-laying birds by a stimulator associated with the egg cycle; and (e) the induction of ESG calbindin mRNA does not need vitamin D metabolites, but 1,25-(OH)2D3 is required for the translation of the mRNA.

Animals↗
PubMedDate not supplied

Embryonated eggs compared with fragments of chorioallantois attached to egg shell for isolation of Newcastle disease virus.

The feasibility of using fragments of chorioallantois attached to egg shell (C-S) as an alternative to embryonated eggs for isolating Newcastle disease virus (NDV) was assessed. In paired titrations of 6 strains of virus, embryonated eggs detected an average of 6-to-7-fold greater amounts of virus than did C-S fragments. The efficiency of isolation of viscerotropic velogenic NDV from 240 swab samples was 97% in embryonated eggs and 84% in C-S fragments. Sensitivity differences between the 2 host systems were revealed only in tests of samples expected to contain small amounts of virus. These results suggest that C-S fragments can be reliably used in some but not all instances, thereby relieving logistic constraints sometimes associated with the use of embryonated eggs.

Allantois↗
PubMed1994

A new biomaterial, hen egg shell membrane, to eliminate heavy metal ion from their dilute waste solution.

The egg shell membrane (ESM) is an intricate lattice network of stable and water-insoluble fibers with high surface area. ESM accumulates and eliminates various heavy metal ions from dilute aqueous solution with high affinity and in short contact time, depending on pH and characteristics of the individual ion. Under certain conditions, the level of precious ions, Au, Pt, and Pd accumulation approaches 55, 25, and 22% of dry wt of ESM, respectively. Also uranium uptake 30% of that of ESM. Experiments suggested that ESM is promising to use for the purpose of removal/recovery of metals and water pollution control.

Adsorption↗
PubMed1984

Collagen in the egg shell membranes of the hen.

Collagen-like proteins have been found in the egg shell membranes of the hen. Materials similar to types I and V collagens were detected in each of the two layers of this membrane, the thick outer membrane and the thin inner membrane. Collagen was extracted by acid-pepsin digestion and isolated by differential salt precipitation. Identification of type-specific collagen-like material was established by coelectrophoresis on SDS-polyacrylamide gels using known collagen standards. These bands were susceptible to digestion by bacterial collagenase. From differential staining of the gels it was estimated that the ratio of collagen types I:V was approximately 100:1. Further confirmation of these biochemical results was obtained with immunofluorescence microscopy using type-specific antisera against chicken types I and V collagen with the indirect sandwich technique. Both the inner and outer shell membranes contained the two types of collagen. Within each membrane, the large, coarse 2.5-micron fibers contained predominantly type I collagen-like material, while type V collagen was mainly associated with the delicate narrower fibers of approximately 0.6-micron diameter. These tended to be concentrated in the inner membrane. At the electron microscopic level, both types of fibers were coated with glycoproteins that stained positively with ruthenium red. The deposition of these collagen-like substances by the hen oviduct on to the surface of the developing egg is an additional example of interstitial-type collagen synthesis and secretion by epithelial rather than by mesenchymal cells.

Animals↗
PubMed1994

The role of home-made ice cream as a vehicle of Salmonella enteritidis phage type 4 infection from fresh shell eggs.

A family outbreak of Salmonella enteritidis PT4 infection is described in which home-made ice cream was identified as the vehicle of infection. The ice cream contained approximately 10(5) S. enteritidis PT4 organisms per gm and was probably contaminated by an infected shell egg containing between 10(5)-10(8) organisms. The continued relevance of the Chief Medical Officer's warning on the use of raw shell eggs is highlighted. Home-made ice cream using the same recipe as ice cream that had been incriminated as the cause of the family outbreak of S. enteritidis PT4 infection was used to study the growth of the organism that might have occurred in the 3-4 h it took to prepare the product. When the inoculum was in the stationary phase, as it would be from shell or other cross contamination, there was a lag phase of 3 h before growth occurred at room temperature. Even when actively multiplying organisms were introduced, as may be found in an infected egg, there was less than 3 log(10) increase in the salmonella count in 4 h at room temperature. It was, therefore, given the high S. enteritidis count, unlikely that the ice cream was cross-contaminated. By contrast, raspberry sorbet at pH 3.73 proved to be lethal to a large inoculum of S. enteritidis and may be a relatively safe raw egg containing product.

Animals↗
PubMed1994

Kinetics of hydrolysis of sucrose catalyzed by invertase immobilized on egg shells and on zeolites.

A simple, inexpensive and reliable method for immobilizing yeast invertase on egg shells and on zeolites was developed. The activity of the immobilized preparations when compared with that of native enzyme at varying pH, temperature and substrate concentrations, showed improved stability and sigmoidal kinetic behaviour. The immobilized enzyme could be easily removed from the reaction mixture at any specified time.

Animals↗
PubMed1989

Characterization of electrolytes and protein content in isthmic and uterine flushings from hens laying shell-less versus hard-shell eggs.

In Experiment 1, hens laying hard-shell (HS) eggs were sacrificed at each of eight stages of egg formation including oviposition (0 h) and 1, 4, 8, 12, 16, 20, and 24 h after oviposition. In Experiment 2, hens laying either shell-less (SL) or HS eggs were sacrificed at four stages of egg formation (oviposition, 4, 8, and 20 h after oviposition). The isthmus and uterus were flushed with 6 and 10 mL of cold .85% NaCl, respectively, and electrolyte contents were determined. Total flushing contents of calcium, potassium, and magnesium were higher (P less than or equal to .01) in uterine than in isthmic flushings (Experiment 1). In every case, an interaction (P less than or equal to .01) between time of collection and organ (isthmus and uterus) was found, indicating that patterns of change in flushing content of each electrolyte differed in the two organs over time in birds laying HS eggs. In Experiment 2, total recoverable calcium, magnesium, potassium, and total protein were higher in uterine than isthmic flushings (P less than .01). Interactions between time of collection (0, 4, 8, and 20 h) and treatment group (SL or HS) were observed for all electrolytes measured in uterine flushings. Results suggest that calcium, required for shell calcification, does not appear in the isthmic or uterine lumen or both at an appropriate time in SL hens. Thus, production of SL eggs may be related to mechanisms regulating patterns of change or ratios of electrolytes (calcium, magnesium, potassium) or both in the isthmus or uterus of the laying hen.

Animals↗
PubMed1984

[Nephroblastoma with egg-shell peripheral calcifications. Apropos of 3 cases].

Three cases of nephroblastoma presented "egg-shell" peripheral calcifications of pseudocystic appearance of radiology. These peripheral lesions are compared with the more commonly reported central calcifications. Their pathology is unknown and they lack prognostic significance of any importance. As for all nephroblastomas the diagnosis is based on straight abdomen images, intravenous urography, ultrasound and computed tomography. Differential diagnosis is basically from renal adenocarcinoma in children, the latter often exhibiting similar calcifications, the distinction between the two types of tumor depending on age of onset. These calcified lesions are non-specific findings and various diagnoses are discussed.

Adenocarcinoma↗
PubMed1996

Egg-shell deposition and blood plasma inorganic phosphorus concentration in individual laying hens.

1. The relationship between plasma inorganic phosphorus measured at the end of the dark period and the weight of the next egg shell produced was investigated in 30 Hisex Brown hens. 2. Hens received an adequate conventional layers' diet and the lighting pattern was conventional (17 L: 7 D). Observations were made early (31 to 40 weeks) and late (62 to 68 weeks of age) in the laying period. 3. Eggs were classified by position in the clutch sequence and significant negative correlations were found between shell weights of early eggs in the sequence and plasma phosphate at the end of the dark period. 4. No significant trends were found in plasma total calcium. 5. No significant differences were found in bone compositions of birds producing consistently more or less than average shell weight during the laying period. 6. The negative correlations between plasma phosphate and shell weight are consistent with the observations of Sauveur and Mongin (1983) and show that impairment of shell deposition is associated with skeletal mobilisation as indicated by increase in plasma phosphate. This is consistent with the observations on bone composition and indicates that selection for shell quality will tend to select birds which are not dependent on excessive skeletal mobilisation during shell formation.

Analysis of Variance↗