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PubMed1992

Research note: eggshell quality in Japanese quail fed different fatty acids.

The purpose of the present study was to determine the effects of diets containing 3% palmitic acid (Diet PA), oleic acid (Diet OA), or linoleic acid (Diet LA) on the shell quality of eggs of Japanese quail. Each diet was fed to 10 hens maintained individually in wire quail laying cages. There was no difference (P greater than .05) in feed consumption between hens fed Diets OA and LA, but hens of both groups consumed less (P less than .05) feed than those fed Diet PA. Egg weight, shell weight, and thickness of shell plus membrane were not influenced by dietary treatment (P greater than .05). However, specific gravity of eggs from hens fed Diet OA was significantly higher (P less than .05) than that of eggs from those fed either Diet PA or Diet LA. Comparison of these data with hatchability data obtained in a previous experiment conducted under similar conditions suggests that the differences in hatchability would not be explained by differences in eggshell quality.

Animals↗
PubMed1986

Calcium intake in relation to ovulation and oviposition when access to oyster shell is time-restricted or unrestricted.

White Leghorn hens were fed either a conventional diet containing 40 gCa/kg from oyster shell, or one low in Ca (3 g/kg) with oyster shell offered separately. In experiment 1 access to oyster shell was unrestricted; in experiment 2. Access was time-restricted to the first 6 h of the photophase of the 14L:10D photoperiod. Irrespective of time-restriction, hens offered oyster shell laid heavier eggs, but shell thickness was reduced. On days on which only ovulation occurred, time-restricted hens consumed significantly less Ca than unrestricted hens. In contrast, on days on which only oviposition occurred, time-restricted hens consumed significantly more Ca than unrestricted hens. These results suggest that when access to oyster shell is time-restricted to morning hours Ca consumption occurs in response to a Ca deficit persisting from the previous period of shell calcification.

Animals↗
PubMedDate not supplied

[Comparative analysis of the glycoproteins of the mineralized tissues of several species of animals].

Studies have been made on carbohydrate components of glycoproteids from normally mineralized tissues of different animals. Experiments were made on the scales of the fish Leuciscus idus, on shells of hen eggs, on shells of the molluscs Modiolus modiolus, Anodonta cygnea, Rapana thomasiana, Bithynia tentaculata, on bone tissue, the enamel and dentine from cows, pigs, dogs and albino rats. In the glycoproteids studied, hexoses, fucoses, ketone sugars, hexosamines, uronic and sialic acids were found and quantitatively determined. Using ion-exchange chromatography on DEAE-Sephadex, acid glycosamineglycanes were divided into two fractions--gialuronic acid and chondroitynsulphates. Marked quantitative, for some of the species qualitative differences as well, were found in carbohydrate composition of glycoproteids from mineralized tissues.

Animals↗
PubMed1985

Shell quality as influenced by zeolite with high ion-exchange capability.

Sixteen dietary treatments applied to a total of 960 hens were used to determine the influence of zeolite A on shell quality and egg size. In Experiment 1, sodium zeolite A (SZA) was fed at three levels (0, .75, and 1.50%) in diets containing 4.0 and 2.75% calcium (Ca) for 8 weeks to old hens. In Experiment 2, the same levels of SZA were fed in diets containing two total sulfur amino acid levels (TSAA, .61 and .51%) to young hens for 12 weeks. Calcium zeolite A (CZA) was also fed at .68% in Experiment 1 in the 4.0% Ca diets and in Experiment 2 in the .51 and .61% TSAA diets. These diets were adjusted for sodium (Na) and chloride (Cl). SZA (.75% unadjusted for Na and Cl) was fed to old hens receiving the 2.75% Ca diet in Experiment 1. All diets were isocaloric and isonitrogenous within diets having the same Ca or TSAA level within an experiment. Response criteria were egg production, feed consumption, egg specific gravity, serum Ca, and body weight. A significant linear response in egg specific gravity occurred within 2 or 3 weeks, when diets supplemented with SZA were fed to old (Experiment 1) and young (Experiment 2) hens. Average Ca intake for control hens (Experiment 1) fed the 2.75 and 4.0% Ca diets was 2.93 and 4.54 g, respectively. Average Ca intake for control hens (Experiment 2) fed the .51 and .61% TSAA diet was 4.38 and 4.00 g, respectively. The CAZ (Experiments 1 and 2) and SZA (unadjusted for Na and Cl, Experiment 1) also gave significant increases in egg specific gravity. Zeolite A had little or no influence on egg weight, feed consumption, or egg production in Experiments 1 or 2. When Na and Cl were not adjusted in the SZA treatments (Experiment 1) a significant reduction in production occurred. It was concluded that zeolite A will significantly increase egg specific gravity and we hypothesize that the mechanism responsible for the significant improvement is related to the high ion-exchange capability of zeolite A.

Aluminum Silicates↗
PubMed1997

Ultrastructure of the calcareous layer eggshell of the turtle Emys orbicularis (L.). Preliminary study.

The calcareous layer of Emys orbicularis eggshell was examined by scanning electron microscopy. The layer is composed of well distinguished shell units which consist of needle-like crystallites radiating outwards from the cores. The linear structures of the cores on the inner surface appear to be similar to those in the eggshell of Mauremys caspica. On the inner surface of shell units of eggs with dead embryos there are flat, conical depressions. This surface in specimens from unfertilized eggs is almost flat. It may suggest that a developing embryo derives calcium from the eggshell.

Animals↗
PubMed1986

Influence of dietary calcium on bone calcium utilization.

In Experiment 1, 10 microCi 45Ca/day were administered to 125 hens for 10 days. Hens were then allocated to five treatments with calcium levels ranging from .08 to 3.75% of the diet. In Experiment 2, hens with morning oviposition times were randomly allocated to 11 treatments that were periods of time postoviposition ranging from 6 hr to 24 hr, in 2-hr increments (Experiment 2). At the end of each 2-hr period, eggs from 25 hens were removed from the uterus. The 18-, 20-, and 22-hr treatments were replicated three times. In Experiment 3, hens were fed either ad libitum or feed was withheld the last 5 or 6 hr before oviposition. In Experiment 4, hens were fed 10 microCi of 45Ca for 15 days to label skeletal calcium. Hens were divided into two groups and fed a .08 or 3.75% calcium diet for 2 days. On the second day, 25 hens fed the 3.75% calcium diet were intubated with 7 g of the same diet containing .5 g calcium at 1700, 2100, 0100, 0500, and 0700 hr. The measurements used were egg weight, shell weight, and 45Ca content of the egg shell. Results indicated a significant linear or quadratic regression of dietary calcium levels on 45Ca accumulation in eggshells and eggshell weight (Experiment 1). As the calcium level of the diet increased, eggshell weight increased and 45Ca recovery decreased. Utilization of skeletal calcium for shell formation ranged from 28 to 96%. In Experiment 2, the rate of shell calcification was not constant throughout the calcification process but varied significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1978

Studies on the avian shell gland during egg formation: the effect of acetazolamide on the transfer of ions to the albumen.

Twenty-five laying hens were fed on a diet containing 100 mg acetazolamide/kg in order to determine the effects of a decrease in the activity of carbonic anhydrase on the transfer of minerals to the egg albumen. Treatment with acetazolamide decreased the rate of shell formation by 44%; reduced the concentrations of water and Na+ in the albumen at the beginning of the plumping stage but increased the accumulation of water during plumping; increased the concentration of Cl- in the albumen after the 6-h stage without any appreciable change in K+ and Ca2+ concentrations. The computed relationships between the concentrations of different ions also showed that the transfer of water and Na+ were linked during egg formation, that a water-independent, acetazolamide-sensitive reabsorption of Na+ occurred after the 10-h stage and that Na+ and Cl- moved simultaneously up to 14 h but with the ratio of Cl- to Na+ three times higher in the treated group. It is concluded that acetazolamide impairs the transfer of Na+ and Cl- between the albumen and the extracellular fluid and that secretion of Ca2+ into the uterine lumen seems to depend on Na+ and Cl- reabsorption.

Acetazolamide↗
PubMed1977

Lithium induction of premature oviposition by the Japanese quail.

1. The intramuscular injection of LiCl into laying Japanese quail 6 or 12 h subsequent to an oviposition induced early oviposition of the next egg. 2. The shells of eggs from Li-treated birds were without speckling and weighed half or less as much as shells from Na-treated birds. Many eggs were also deficient in albumen.

Animals↗
PubMed1984

Calcium metabolism in embryos of the oviparous snake Coluber constrictor.

Total calcium in embryos of an oviparous, colubrid snake (Coluber constrictor L.) rises rapidly during the last half of incubation as the embryos increase in size. Although most of this calcium is drawn from stores in the yolk, hatchlings contain more calcium than was present in yolk of eggs at oviposition. Because shells from eggs incubated to hatching contain less calcium than do shells from freshly-laid eggs, the extra calcium appears to be drawn from the eggshell. Indeed, approximately 20% of the calcium required for development in this snake is obtained from the eggshell, with the remainder coming from the yolk. Thus, embryos of oviparous snakes, like embryonic chelonians, crocodilians and birds, withdraw calcium from their eggshells and do not rely exclusively on calcium supplied in their yolk for support of growth and development.

Animals↗
PubMed1984

Biochemical changes in blood and uterine fluid of fowl following experimental EDS'76 virus infection.

The pH, pCO2, and pO2 values and the concentrations of sodium, potassium, calcium, magnesium, chloride, phosphorus, bicarbonate, base excess, protein, glucose, as well as the activity of alkaline phosphatase and malate dehydrogenase were determined in the venous blood and uterine fluid of control and EDS'76 virus-infected fowl. Moreover, the pH of the mucosa of different parts of the oviduct was measured. Hens were examined in the period from 10 to 24 days following infection; blood and uterine fluid samples were collected approximately 14 hours after oviposition, provided a plumped egg was present in the uterus. Examination of blood and pH measurement of oviduct mucosa did not yield significant differences between infected and noninfected hens. In comparison with noninfected control birds, the mean sodium concentration of the uterine fluid of infected hens producing soft shelled or shell-less eggs had evidently increased, while the mean concentration of potassium, calcium, magnesium and glucose had decreased. Similar differences were also observed between infected hens producing normally shelled eggs and infected hens producing abnormally shelled eggs. No significant differences between infected and not infected hens were observed concerning the other values determined in the uterine fluid. It is concluded that functional disturbances which account for shell aberrations following EDS'76 virus infection are located in the surface epithelial cells of the uterine mucosa. These disturbances are very probably initiated by a depressed function of the sodium pump. All changes observed in the uterine fluid of infected hens could be explained by this depressed function.

Adenoviridae Infections↗
PubMed2006

The magnum-isthmus junction of the fowl oviduct participates in the formation of the avian-type shell membrane.

Avian eggs possess a shell membrane in the shape of an asymmetrical ellipsoid and with a limiting membrane that is a smooth layer of homogeneous, dense materials. We describe the role of the magnum-isthmus junction (MIJ) of the oviduct in the formation of the avian-type shell membrane in the domestic fowl Gallus domesticus. The narrow width of the lumen at the MIJ indirectly participates in the determination of the asymmetrical ellipsoid shape of eggs that are encased by the egg-white layer and subsequently by the peri-albumen layer (PL) and the shell membrane. The PL reacts with Alcian blue and exists between the egg white and the limiting membrane. It is added to the ovulating egg at the MIJ and covers the outermost surface of the egg-white layer. The function of the PL is to provide a smooth surface by covering the irregular surface of the egg-white layer. The materials of the PL consist of an Alcian blue-positive polysaccharide (or glycoprotein) of 240 kDa and five proteins of 135, 116, 72, 49, and 46 kDa. The isolated materials have an affinity to bind with the egg-white mass. An antiserum against quail PL materials stains the domestic fowl PL and secretory cells of the luminal epithelium at the MIJ, and cross-reacts with the molecules of 240, 135, and 116 kDa.

Animals↗
PubMed1987

Scanning electron microscopy of thin and soft shells induced by feeding calcium-deficient or vitamin D-deficient diets to laying hens.

A scanning electron microscopic study was conducted on shells from eggs laid by four groups of hens maintained on different types of diets: a) control, b) vitamin D3-deficient, c) Ca-deficient, and d) vitamin D3-deficient supplemented with 1,25-(OH)2D3. After 1 week for Ca-deficient hens and after 4 weeks for vitamin D3-deficient hens, the thickness of the shell decreased abruptly and numerous thin-shelled and soft-shelled eggs were laid. The study showed that with both Ca-deficient and vitamin D3-deficient diets, the outer layers of the shell (cuticle and spongy) were reduced or absent but the mammillary layer was present even in the thinnest soft-shelled egg. The order in which layers disappeared as treatment progressed was exactly the reverse of the order in which these layers are formed in normal eggs. No eggs were found without mammillary knobs, which suggests that the hens stop laying before Ca concentrations in blood become too low for the formation of the mammillary knobs. Uncalcified portions of the shell organic matrix were never found, suggesting that Ca deposition and matrix formation were inhibited simultaneously. The relationship between fibers of the shell membrane and mammillary knobs was preserved in all cases. The eggshells from hens on 1,25-(OH)2D3-supplemented diets were ultrastructurally indistinguishable from those of hens on diets adequate in vitamin D3.

Animals↗
PubMed2004

Palaeontology: pterosaur egg with a leathery shell.

The recent discovery of a pterosaur egg with embryonic skeleton and soft tissues from the Yixian Formation confirmed that the flying pterosaurs were oviparous. Here we describe another pterosaur egg whose exquisite preservation indicates that the shell structure was soft and leathery.

Animals↗
PubMed1996

Salmonella enteritidis in eggs, cloacal swab specimens, and internal organs of experimentally infected White Leghorn chickens.

OBJECTIVE: To investigate prevalence of Salmonella enteritidis-positive eggs, excretion of the organism in fecal droppings, and infection of internal organs after oral inoculation of White Leghorn hens with S enteritidis phage type 8. ANIMALS: 30 White Leghorn laying hens. PROCEDURE: At 25 weeks of age, hens were each inoculated orally with 10(10) colony-forming units of S enteritidis, then were observed for 8 weeks. RESULTS: Salmonella enteritidis Y-BP2 did not cause any clinical signs of disease or decrease in egg production. However, at 1 week after inoculation, 63.9% of the eggs collected from inoculated hens were culture positive for S enteritidis. The organism was isolated from the shell washings, egg shells, yolk, and albumen. A total of 592 eggs from S enteritidis-inoculated hens were examined. Of these eggs, 157 (26.5%) were positive for S enteritidis on external shell washings alone, 17 (2.9%) were positive for S enteritidis internally, and 44 (7.4%) were positive for S enteritidis externally and internally. The percentage of culture-positive eggs gradually decreased between postinoculation weeks 2 and 5, then gradually increased to a high of 76% at week B. At 3, 7, and 10 days after S enteritidis inoculation, cloacal swab specimens from 3 hens were positive for S enteritidis. Salmonella enteritidis was recovered from ovary, oviduct, liver, and cecal junction from S enteritidis-inoculated hens. CONCLUSIONS: Our results indicated that birds infected with this isolate produced S enteritidis-positive eggs at high frequencies initially, that decreased over time. When S enteritidis antibody began to decrease, reaching geometric mean titer < or = 40, the frequency of S enteritidis-positive eggs increased.

Analysis of Variance↗
PubMed1994

Chlorinated hydrocarbons and shell thinning in eggs of (Accipiter) hawks in Ontario, 1986-1989.

Eggs of sharp-shinned hawks (Accipiter striatus), Cooper's hawks (A. cooperii), and northern goshawks (A. gentilis) were collected from nests in south-central Ontario from 1986 to 1989. Detectable levels of the chlorinated hydrocarbons DDE, DDT, DDD, mirex, photomirex, cis-nonachlor, trans-nonachlor, oxychlordane, dieldrin, heptachlor expoxide, HCB and PCB were present in all the eggs analyzed. Mean contaminant levels were highest in sharp-shinned hawks, slightly lower in Cooper's hawks, and significantly lower in goshawks; for example, mean DDE values were 7.23, 4.48 and 0.90 mg kg(-1) (wet weight), respectively. Total PCB levels were generally less than 1.5 mg kg(-1), lower than those associated with reproductive effects in field and laboratory studies with other species. Mean shell thicknesses of sharp-shinned and Cooper's hawk eggs were significantly less than mean pre-DDT era thicknesses (-10 and -8%, respectively), reductions that were probably not relevant to reproductive success. Goshawk eggs exhibited no significant reduction in shell thickness. Contaminant levels among the three species probably reflect differing food habits and migratory patterns.

Journal Article↗
PubMed1987

Ahemeral light-dark cycles and egg production parameters of ring-necked pheasants (Phasianus colchicus).

The effects of two ahemeral light-dark (L:D) cycles on ring-necked pheasant egg production were investigated in this experiment. Three groups of 36 female and 12 male 10-month-old birds were exposed to control 24-hr (14L:10D), ahemeral 22-hr (14L:8D), or ahemeral 26-hr (14L:12D) L:D cycle. Average percent hen-day egg production (HDEP) was 63.8 for hens exposed to ahemeral 26-hr L:D cycle compared with 55.6% HDEP for the controls. Although this was not significant (P less than .05). It suggests a trend for pheasants exposed to ahemeral L:D cycles to improve egg production. Ahemeral L:D cycles did not significantly (P greater than .05) affect egg mass, shell-less eggs, cracked eggs, egg hatchability, and embryonic mortality. Shell quality, measured by specific gravity and shell thickness, was significantly (P less than or equal to .05) reduced for eggs obtained from hens exposed to ahemeral 22-hr L:D cycle. Fertility of eggs from hens kept under ahemeral 26-hr L:D cycle was significantly (P less than or equal to .05) improved compared with fertility of eggs from controls (89.3 vs. 78.4). Results of this research suggest that long ahemeral L:D cycles do play a role in the improvement of pheasant egg production and egg fertility.

Animals↗
PubMed1978

Studies on the avian shell gland during egg formation: the effect of acetazolamide on the composition of the mucosa.

The effect of acetazolamide, an inhibitor of carbonic anhydrase activity, on the intracellular composition of the shell gland mucosa was determined. The normal cyclic hydration of the mucosal cells was found to be reduced when the egg was in the uterus and the partition of the water between the intra- and extracellular compartments was modified. Acetazolamide decreased the accumulation of Na+ within the cells, inhibited the Na+-independent movement of Cl- and reduced the transfer of Cl- linked with Na+. It is concluded that acetazolamide blocks the intracellular generation of HCO3- and the reabsorption of Cl-.

Acetazolamide↗
PubMed1984

Effects of suppression of eggshell calcification and of 1,25(OH)2D3 on Mg2+, Ca2+ and Mg2+HCO-3 ATPase, alkaline phosphatase, carbonic anhydrase and CaBP levels--I. The laying hen uterus.

Stimulation of Mg2+, Ca2+ and Mg2+HCO-3 dependent ATPase activity in mitochondrial and microsomal fractions from the uteri of laying hens is demonstrated. ATPase activity was greatest with 5 mM concentrations of Mg2+ at pH 8.5, and at pH 7.4-7.8 following the addition of bicarbonate. Suppression of eggshell calcification, induced by insertion of a thread into the uterus, did not alter Mg2+, Ca2+ and Mg2+HCO-3 ATPase activities. Alkaline phosphatase activity was generally low, and was unaffected by suppression of eggshell calcification. Levels of carbonic anhydrase and calcium binding protein were lower in the uteri of hens laying shell-less eggs. Injections of 1,25(OH)2D3 in hens laying shell-less eggs did not alter CaBP levels or enzyme activities. It is concluded that factors other than 1,25(OH)2D3 and gonadal hormones are involved in the regulation of uterine CaBP levels.

Adenosine Triphosphatases↗