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At least 469 records · Page 26Linked to original sources
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

Effects of breeder age and dietary fat source and level on broiler hatching egg characteristics.

The effects of breeder age and added dietary fat source and level on broiler hatching egg characteristics were evaluated. Diets included no added fat (NAF) or 3.0% added poultry fat (PF) for peak energy intakes of 430 and 467 kcal/hen-day (PCD) or 1.5% PF or 3.0% corn oil (CO) at 449 PCD. As added dietary fat was changed from CO to PF, the percentage of unsaturated dietary fatty acids, including linoleic acid, decreased. Feeding of experimental diets was initiated when breeders were 22 wk old. Total fresh egg weight; eggshell weight; percentages of yolk (PYK), albumen (PAB), and eggshell (PSHL) weights; and yolk:albumen ratio were measured at various weeks between 26 and 47 wk of age. Egg weight increased progressively with hen age. Significant increases in yolk:albumen ratio occurred between Weeks 26 and 31 and between Weeks 31 and 35. Low (430 PCD) dietary energy levels significantly reduced PYK at 35 wk and increased PAB across breeder age. Eggshell weight was lower in birds fed moderate (449 PCD) compared to low energy levels at Week 26, moderate compared to high (467 PCD) energy levels at Week 41, and PF compared to CO across fat level at Week 31. At Weeks 31 and 41, PSHL was increased by the use of 3.0% PF compared to 1.5%, and PSHL was increased at Weeks 26 and 41 by using added PF compared to CO across fat level. Increased dietary energy decreased PAB and the use of added dietary CO rather than PF decreased PSHL in broiler breeders between 26 and 47 wk of age.

Age Factors↗
PubMed1992

Alligators provide evidence for the evolution of an archosaurian mode of oviparity.

The female reproductive tract of birds is different from that of other oviparous amniotes in that the eggshell membranes and calcareous layer are formed in separate regions of the uterus; the isthmus and shell gland, respectively. Phylogenetically, birds are included among the archosaurs, along with crocodilians and dinosaurs. Many dinosaurs were oviparous, producing hard-shelled eggs, yet the reproductive system of dinosaurs has proven difficult to investigate, due to poor preservation of soft anatomy. In this study, we examined functional morphology and eggshell formation in a reptilian archosaur, the American alligator, and demonstrated that the crocodilian reproductive tract has separate uterine regions for formation of the eggshell membranes and calcareous layer. These uterine regions are ultrastructurally comparable to the isthmus and shell gland of birds, and may be homologous. This similarity of reproductive functional morphology between crocodilians and birds may implicate the evolution of an archosaurian mode of oviparity that may shed light on dinosaur reproduction.

Alligators and Crocodiles↗
PubMed1994

Preventing heel pressure sores: a comparison of heel pressure relieving devices.

It has been widely recognized that elderly patients with an orthopaedic problem are predisposed to developing heel pressure sores. In this study four pressure-reducing devices, commonly used in the prevention of heel ulcers, were objectively compared for their ability to decrease or remove pressure on the heels of patients with fractured necks of femurs and fractured femurs. Forty-one patients were randomly allocated a pressure relieving device. The efficacy of the device was evaluated by continuously assessing the skin integrity of both heels on a daily basis over a period of 12 days. Data were collected over a 30 month period. The four devices were foam splints, eggshell foam, duoderm and heel protector boots. Foam splints and eggshell foam proved to be more effective devices in relieving pressure exerted on the heel. This study recognizes that meticulous nursing care remains the critical element in prevention of heel ulcers; however, the use of eggshell foam and foam splints in conjuction with this enhances the maintenance of skin integrity.

Aged↗
PubMed1988

Indexes of vitamin D deficiency in Japanese quail embryos.

Effects of vitamin D deficiency (-D) on mineral homeostasis were investigated in Japanese quail embryos. The -D embryos from 1,25(OH)2D3-fed hens became progressively calcium deficient, as documented by hypocalcemia and reduced calcium accumulation by the skeleton, yolk sac, and allantoic fluid. Plasma phosphate was progressively elevated between days 11 and 15. Increased calcium accumulation by the skeleton, yolk sac, and allantoic fluid occurred between days 12 and 15 in +D embryos. Phosphate and adenosine 3',5'-cyclic monophosphate (cAMP) concentrations of allantoic fluid increased in +D embryos during the period of shell calcium mobilization. Further increases in phosphate and cAMP excretion into allantoic fluid occurred in -D embryos, although no calcium was absorbed from the shell. Renal 25(OH)D-1-hydroxylase activity increased between days 11 and 13, whereas the adenylate cyclase response to parathyroid hormone was lost in -D embryos by day 14. These changes in renal function are indicative of secondary hyperparathyroidism in the -D embryos. Differentiation of villus cavity and capillary covering cells occurred in the chorionic epithelium of -D embryos, but eggshell calcium was apparently not absorbed. In contrast, 75% of the total body calcium of newly hatched (+D) chicks was obtained from the eggshell. Thus the dissolution and/or transport of eggshell calcium is dependent on vitamin D in quail embryos.

Adenylyl Cyclases↗
PubMed2002

Modeling and computational analysis of EGF receptor-mediated cell communication in Drosophila oogenesis.

Autocrine signaling through the Epidermal Growth Factor Receptor (EGFR) operates at various stages of development across species. A recent hypothesis suggested that a distributed network of EGFR autocrine loops was capable of spatially modulating a simple single-peaked input into a more complex two-peaked signaling pattern, specifying the formation of a pair organ in Drosophila oogenesis (two respiratory appendages on the eggshell). To test this hypothesis, we have integrated genetic and biochemical information about the EGFR network into a mechanistic model of transport and signaling. The model allows us to estimate the relative spatial ranges and time scales of the relevant feedback loops, to interpret the phenotypic transitions in eggshell morphology and to predict the effects of new genetic manipulations. We have found that the proposed mechanism with a single diffusing inhibitor is sufficient to convert a single-peaked extracellular input into a two-peaked pattern of intracellular signaling. Based on extensive computational analysis, we predict that the same mechanism is capable of generating more complex patterns. At least indirectly, this can be used to account for more complex eggshell morphologies observed in related fly species. We propose that versatility in signaling mediated by autocrine loops can be systematically explored using experiment-based mechanistic models and their analysis.

Animals↗
PubMed1993

Transepithelial calcium transport in the chick chorioallantoic membrane. I. Isolation and characterization of chorionic ectoderm cells.

The chicken eggshell supplies approximately 80% of the calcium found in the hatchling chick. The mobilization of eggshell calcium into the developing embryo involves the transepithelial transport of large amounts of calcium in a development-specific manner. The cells responsible for the transport of eggshell calcium into the embryonic circulation are the ectodermal cells of the chorioallantoic membrane. In this report, we present a method for the isolation and culture of chorioallantoic membrane ectodermal cells, which are amenable to direct experimental manipulation. Cell preparations are characterized with respect to the expression of an ectoderm-specific cell surface marker (transcalcin, a calcium-binding protein), and a specific enzymatic activity (elevated Ca(2+)-activated ATPase). Functional assessment of in vitro cellular calcium uptake by 45Ca2+ tracer kinetics indicates the persistence of a temperature-sensitive, rapid-influx pathway similar to that observed in vivo. The preparations of primary ectodermal cells present an in vitro system applicable to the experimental analysis of calcium metabolism and transport by the chick chorioallantoic membrane.

Allantois↗
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↗
PubMed2001

Dicofol residues in eggs and carcasses of captive American kestrels.

American kestrels (Falco sparverius) were fed diets containing 0 (control), 1, 3, 10, and 30 microgram/g (wet wt) of Kelthane. Residues of dicofol and its metabolites were then analyzed in the eggs and carcasses of females. Significant differences occurred among treatments for residues of both p,p'-dicofol and p,p'-dechlorodicofol (DCD) in both eggs and carcasses and for p,p'-dicholorbenzophenone (DCBP) in eggs. Residue concentrations increased with increasing treatment exposure. Residues of p,p'-dicofol, p,p'-DCD, and p,p'-DCBP in eggs were significantly correlated with eggshell quality parameters. Significant correlations also occurred among contaminants in eggs and for individual contaminants between eggs and carcasses. The lowest-observed-dietary-effect concentration for eggshell thinning was 3 microgram/g, whereas 1 microgram/g may be considered to be near a no-observable-adverse-effect concentration. Concentrations of dicofol in potential prey items and eggs of wild birds generally have been lower than dietary-effect concentrations or concentrations in tissues or eggs associated with eggshell thinning and reduced reproductive success.

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↗
PubMed1990

Effect of a quaternary ammonium sanitizer for hatching eggs on their contamination, permeability, water loss, and hatchability.

The present study tested the biocidal effectiveness of the quaternary ammonium Hatching Egg Sanitizer Spray (HES Spray) in disinfecting broiler hatching eggs and in terms of its effects on eggshell permeability, water loss, and hatchability. The application of HES at a 1.5% or a 3.0% concentration resulted in significant reductions in the total aerobic counts on the egg surface of 98.1% and 99.9%, respectively, within 30 min of application. Molds and yeasts were significantly reduced by 3.0% HES at 14 days of incubation. Significant reductions in total aerobic counts on the egg surface due to 1.5% and 3.0% HES were also observed on eggs that were allowed to "sweat." The 3.0% HES concentration also reduced coliforms on egg surfaces. Hatchability of fertile eggs from a 32-wk-old flock was significantly increased, over 6.0%, by spraying 1.5% or 3.0% HES in comparison to controls that were not sprayed, with no significant difference in hatchability due to treatment observed in eggs from flocks that were 36, 42, 46, or 62 wk of age. This change in hatchability associated with spraying HES may be due to a change in eggshell permeability (respiration) caused by an interaction of HES with the eggshell cuticle.

Animals↗
PubMed1993

Ultrasonography as a tool for monitoring in ovo chicken development. 1. Technique and morphological findings.

Preliminary studies were performed to develop a method for using real-time, B-mode ultrasonography (US) to directly image the internal morphology of the chicken egg and developing embryo. Different soft tissue interfaces will reflect US waves differentially. These reflected waves, or echoes are then converted into a two-dimensional image of internal morphology. A major limitation of diagnostic US is its inability to penetrate through gas or hard tissue (bone, shell) interfaces. Methodology development to overcome the acoustic obstacle presented by the eggshell and air cell constituted the initial part of the preliminary study. An acoustical window was achieved by creating a 2-cm fenestration through the large end of the eggshell, then filling the air cell with sterile saline. Morphological features of the yolk and embryo were recorded at 0, 2, 6, 9, 14, and 17 days of incubation. The second part of the preliminary study explores whether the acoustic window, once created, could then be closed, and if closed, whether egg viability could be maintained. A second concurrent trial was conducted with 32 eggs that were fenestrated, imaged, recorded, reclosed, and incubated. Two methods of closure were attempted: one using dialysis membrane and tape; the other using an eggshell allograft. Hatchability was partially retained with both window closure methods.

Animals↗
PubMed1995

Egg characteristics, carbohydrate metabolism, and thyroid hormones in late chick embryos from different genetic lines.

Functional eggshell qualities, thyroid hormones, and carbohydrate metabolism of chick embryos at the end of incubation were compared between a modern (Arbor Acres line) and a randombred control population (Athens-Canadian Randombred). Embryos from the Arbor Acres genetic line developed in larger eggs with more albumen and less yolk than Athens Canadian Randombred lines. Percentage shell and functional eggshell properties measured as eggshell conductance constants did not differ between genetic lines. On a relative basis, hearts were generally smaller and livers heavier in Arbor Acres than in Athens-Canadian Randombred birds. Heart and liver glycogen concentrations were greater in Athens-Canadian Randombred than in Arbor Acres embryos. However, blood glucose was greater in Randombred than in Arbor Acres embryos only at internal pipping, a time of hypoxia and hypercapnia. Blood plasma concentrations of thyroxine did not differ significantly between the modern and Randombred embryos at any stage examined. Modern broiler chick embryos possessed greater concentrations of triiodothyronine as well as greater triiodothyronine to thyroxine ratios than Randombred embryos at external pipping and hatching. It can be inferred from the data that chick embryos differ in their use of carbohydrate during late development between modern and Randombred genetic lines.

Animals↗
PubMed1998

Bacterial penetration into eggs washed with various chemicals and stored at different temperatures and times.

Eggs were washed with one of three commercial egg-washing chemicals, including a quaternary ammonium compound (QAC, pH 7.5), sodium carbonate (Na2CO3, pH 12), and sodium hypochlorite (NaOCl, 100 ppm, pH 7.5). One hundred fifty intact-shell eggs were washed at 43.3 degrees C with each of three chemicals. A control group was washed with tap water (H2O, pH 7.0). The washed eggs then were inoculated by immersion for 3 min into an aqueous suspension of Salmonella enteritidis at 10(4) colony-forming units/ml and dried for 30 min. The washed and inoculated eggs were stored at 4 degrees C or 23 degrees C, and bacterial penetration was checked at 0-, 7-, 14-, and 21-day intervals. The effects of egg-washing chemicals on microstructural changes of eggshell and postwash inoculation were examined using electron microscopy and conventional culture methods. Fifteen eggs were used in each sample. The results of microbial tests showed that both QAC and sodium hypochlorite treatments reduced bacterial penetration (less than 3.4% and 6.7%, respectively, on day 1 and 16.7% on day 21). The sodium carbonate treatment facilitated bacterial penetration during egg storage (less than 30% on day 1 and 76.7% on day 21). The eggs washed with tap water had a bacterial penetration rate of less than 6.7% on day 1 and 20% on day 21. As the storage intervals increased to 21 days, the bacterial penetration rate increased. Different storage temperatures (4 degrees C and 23 degrees C) did not cause a significant difference in bacterial penetration rates within 21-day interval. The results of electron microscopy showed that QAC and sodium hypochlorite at 100 ppm resulted in microbiologically clean eggs and did not destroy eggshell surfaces, which protected the eggs against future bacterial recontamination. The alkaline sodium carbonate produced visually clean eggs but altered the eggshell surface, which allowed bacterial recontamination.

Animals↗
PubMedDate not supplied

The effects of ts-11 strain Mycoplasma gallisepticum vaccination in commercial layers on egg production and selected egg quality parameters.

Live Mycoplasma gallisepticum (MG) vaccines have been USDA approved and licensed for use in commercial layer chickens since 1988; however, egg production and egg quality data exist only for the F strain of MG. Information pertinent to the effects of ts-11 MG on egg and eggshell quality parameters, as well as egg size distribution, is lacking. In this study, pullets were inoculated at 10 wk of age with ts-11 strain MG and placed in biological isolation units at 10 birds/unit. Hen-day egg production, eggshell strength, Haugh unit score, pimpling incidence, and blood/meat spot incidence were monitored and recorded in each trial through a 45-wk production cycle. Further, eggs from all treatments were collected daily, Monday-Thursday, and individually weighed. Results of this study indicate that no significant difference was observed between the treatments for the parameters measured or for egg size distribution. Therefore, these data should lessen producers' concerns pertaining to the impact of ts-11 strain MG on egg production, egg and eggshell quality parameters, and egg size distribution.

Animals↗
PubMed1991

Effect of acetazolamide on calcium accumulation by the developing chicken embryo.

The injection of 10 mg of acetazolamide into fertile chicken eggs on the 16th or 17th day of incubation resulted in a decreased accumulation of calcium by the developing embryo. A dose of 1 mg of acetazolamide did not affect embryonic calcium content. Although the eggshell serves as the primary source of calcium for the embryo, acetazolamide did not influence eggshell mobilization as measured by the release of 45Ca from labeled eggshells. Acetazolamide did decrease bone formation resulting in a statistically significant reduction in tibia dry weight and calcium content.

Acetazolamide↗
PubMed1988

[Regulation by cations of adenylate cyclase activity in chicken tissues].

The effects of magnesium and sodium ions on adenylate cyclase activity in plasma membranes from chicken heart and eggshell gland mucosa were studied. It was found that the increase in magnesium chloride concentration from 5 to 40 mM results in the stimulation (4.1-fold) of the adenylate cyclase activity. The increase in sodium chloride concentration up to 150 mM stimulated the enzyme activity 2-fold. The stimulation of adenylate cyclase by magnesium and sodium ions was less pronounced in the eggshell gland. GTP did not activate adenylate cyclase. The activating effect of magnesium and sodium ions was accompanied by the attenuation of the enzyme sensitivity to NaF, guanylyl imidodiphosphate and isoproterenol. Activation by guanylyl imidodiphosphate was completely abolished in the presence of 40 mM magnesium chloride. It is assumed that high concentrations of the salt promote subunit dissociation of the adenylate cyclase regulatory protein and its interaction with the catalytic subunit in the presence of endogenous nucleotides. The differences in the adenylate cyclase sensitivity to cations in chicken heart and eggshell gland mucosa correlate with the amount of pertussis toxin substrate.

Adenylyl Cyclases↗
PubMedDate not supplied

Reproductive capacities of control bobwhite quail (Colinus virginianus) during one-generation reproduction studies.

The Bobwhite quail (Colinus virginianus) is the avian model of choice for testing the reproductive impairment potential of pesticides and environmental contaminants. While the literature contains numerous reports on the effects of pesticides on eggshell development for quail, mallards and other avian species (Haegele and Tucker, 1974; Kolaja, 1977; Jenkins et al., 1974) limited control data for reproductive evaluation of pesticides can be found. This paper summarizes the control data from three one-generation reproductive studies in Bobwhite quail. One male and two female adult quail were housed in clean pens with tap water and game bird breeder ration available ad libitum. The pre-laying cycle was ten weeks in duration. The photoperiod was seven hours of light per day for the first eight weeks and was increased to 17 hours of light per day in order to induce egg laying. Eggs were collected daily for eight weeks and incubated. Biweekly, one egg from each pen was removed and used for determination of eggshell thickness. The mean reproductive indices for these studies are: Eggs cracked/Eggs laid--8.2%, Viable 11-day embryos/Eggs set--73.6%, Viable 21-day embryos/Viable 14-day embryos--98.9%, Hatchlings/Viable 21-day embryos--82.0%, 14-day survivors/Hatchlings--76.3%. The mean eggshell thickness for 144 eggs was 0.301 mm.

Animals↗