Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Egg Shell”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 19 recordsLinked to original sources
PubMedDate not supplied

[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.

Amino Acids↗
PubMed1990

Effect of 1 alpha,25-dihydroxycholecalciferol on egg shell quality and egg production.

1. The effect of replacing dietary cholecalciferol (D3) by 1 alpha,25-dihydroxycholecalciferol (1,25-(OH)2D3) on egg shell quality and egg production was tested on 32-week-old White Leghorn laying hens over 9 weeks. 2. Hens fed on a diet supplemented with 5 micrograms 1,25-(OH)2D3/kg diet, tended to lay more eggs, and the eggs had significantly higher specific gravity and percentage shell than eggs from control hens fed on a diet supplemented with 27.5 micrograms D3/kg diet. 3. The effect became apparent after about 4 weeks of treatment and persisted until the end of the test. 4. Hens fed on a diet without D3 supplement started to lay very thin or soft shelled eggs within 4 weeks, suggesting that the birds' reserves of D3 or its metabolites were depleted within this period. 5. The results suggest that 1,25-(OH)2D3 can be substituted for D3 in layer diets to improve egg shell quality.

Animals↗
PubMed1978

Influence of hen dietary calcium and phosphorus on the integrity of the egg shell as it would influence hatching success and the consequences of preincubation 2, 4, 5-T spraying with and without a high TCDD level.

Commercial strain laying hens were fed practical rations deficient in calcium and/or phosphorus to affect weak shelled eggs. Spraying these eggs prior to incubation with 2, 4, 5-T preparations having extremes in TCDD contamination at 10x recommendation was without effect on all parameters used to evaluate embryological development and subsequent early performance of resultant chicks. Analyses for 2, 4, 5-T residues indicated that the shell though weakened was unaffected as a barrier to herbicide contamination.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed1975

Effect of chlorinated hydrocarbons on shell gland carbonic anhydrase and egg shell thickness in Japanese quail.

Japanese quail (Coturnix japonica) were fed different levels of pesticide in their diets for 15 weeks. The levels of pesticide used were 25, 50, 100, 200 p.p.m. DDE 25, 50, 100, 200 p.p.m. DDT and 50 p.p.m. PCB. Carbonic anhydrase activities were analyzed in the shell glands and blood; pesticide concentration in the eggs of the first experiment was measured; egg weight, shell weight and shell thickness were also measured. No depression in growth was observed at any levels of pesticides used. Quail fed 200 p.p.m. DDE showed a high mortality rate after 10--12 weeks on the diet, while other levels produced no increase in death rate. Lower levels of DDT and DDE (25 and 50 p.p.m.) had no significant effect on egg shell weight or thickness. Higher levels (100 and 200 p.p.m) of DDT and DDE produced a small increase in shell weight and a 5 per cent decrease in shell thickness and were associated with increased shell breakage. At levels of 25 p.p.m. and 50 p.p.m. DDE, the activity of carbonic anhydrase in the shell gland was significantly increased. At levels of 200 p.p.m. DDE and 100 p.p.m. DDT in the diet, the activity of carbonic anhydrase was decreased by 12--15 per cent. A 50 per cent reduction in carbonic anhydrase activity in the shell gland seemed to be necessary for an increased production of soft shelled eggs when it was induces by sulfanilamide. Pesticide residues in the eggs of Japanes quail up to about 300 p.p.m. DDE and 150 p.p.m. DDT were not associated with any change in egg shell thickness. At about 600 p.p.m. DDE and 500 p.p.m. DDT in the eggs, corresponding to 100 and 200 p.p.m. in the diet, the egg shell thickness was reduced by 5 per cent. PCB at 50 p.p.m. produced a small decrease (4.5 per cent) in shell thickness and an increase in the percentage of cracked eggs.

Animals↗
PubMed1989

Characterization of shell gland lipids from chickens (Gallus domesticus) producing strong or weak egg shells.

1. The reduction in egg shell strength in hens at the end of the first reproductive cycle was not associated with abnormal uterine or body fat accumulation. 2. The phosphatidylcholine concentration was greater in the shell glands of hens producing strong egg shells compared to that of producing weak egg shells. 3. Differences were not detected in the total lipid or cholesterol concentrations or the fatty acid profiles of phosphatidylcholine or phosphatidylethanolamine fractions. 4. Following an induced molt, the fatty acid profile of the total lipid fraction of the shell gland was altered with a decrease in stearic acid and an increase in oleic acid. 5. The results demonstrate that alterations in egg shell strength are mainly associated with changes in shell gland phospholipid polar head group composition and not with changes in phospholipid fatty acid profile or cholesterol concentration.

Animals↗
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↗
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↗
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↗
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↗
PubMed1987

The relation between sodium chloride concentration in drinking water and egg-shell damage.

1. A significant linear increase in egg-shell defects from 60-week-old laying hens, and corresponding significant linear decreases in various egg-shell-quality measurements, were observed in response to increasing concentrations of sodium chloride in the drinking water, to the maximum concentration of 600 mg/l used in the present study. 2. The incidence of damaged egg shells was increased 3-fold by including NaCl in the drinking water at a concentration of 600 mg/l. 3. Shell defects declined when birds were placed on normal water for 5 weeks but were still 1.4- to 2.1-fold greater than control values. 4. After an induced rest from lay on normal water, shell defects were still 1.3- to 3.2-fold greater in birds which had previously received the NaCl in the drinking water. 5. The increased incidence of shell damage was not related to decreased food intake or increased egg weight or production.

Animals↗
PubMed1986

Categorisation and causes of abnormal egg shells: relationship with stress.

Concern regarding the proportion of brown eggs being laid with abnormal egg shells led to an investigation of the relationship between disturbance or stress and egg shell appearance and quality. The abnormalities fell into two main classes: misshapen or bulging eggs and eggs coated with a superficial layer of amorphous calcium, variously termed dusted, white banded, chalky or pink eggs. Translocation of hens from pens to cages resulted in a decrease in egg production and an increase in the proportion of abnormal eggs over the succeeding 18 d. Disturbance to flocks on deep litter resulted in an increase in the proportion of eggs laid with abnormal shells on the following day, not only in the flocks directly affected but also in an adjacent flock. Exclusion from their nests of birds accustomed to laying in nest boxes resulted in disturbed prelaying behaviour, retention of eggs in the shell gland and an increased proportion of coated eggs. Administration of 0.1, 0.25 or 1.0 mg of adrenaline subcutaneously resulted in the retention of eggs currently in the hens' shell glands and in an increased proportion of eggs with abnormal egg shells being laid during the following 10 d. A dose response effect was apparent. There was evidence that the nature of the particular abnormality produced was dependent on the stage of egg formation at which the disturbance was imposed and, if retention followed, upon the length of time the egg was retained. Disturbances when eggs were only lightly calcified tended to result in misshapen eggs, while those occurring when oviposition was imminent tended to result in coated eggs. Dusted or pink eggs followed moderate retention whereas white banded eggs were seen after prolonged retention. These observations may provide a basis for a non-invasive method of assessing stress in laying hens as well as helping to account for hitherto inexplicable occurrences of declining egg shell quality.

Animals↗