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IMMUNOLOGY, HEALTH AND DISEASE |
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* Poultry Research Unit, Agricultural Research Service, USDA, Mississippi State, MS 39762; Department of Applied Economics and Statistics, Clemson University, Clemson, SC 29634; and Department of Poultry Science, Mississippi State University, Mississippi State, MS 39762
3 Corresponding author: dpeebles{at}poultry.msstate.edu
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ABSTRACT |
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 TOP ABSTRACT INTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONREFERENCES |
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Key Words: commercial layer • egg characteristic • egg quality • F-strain Mycoplasma gallisepticum • ts11-strain Mycoplasma gallisepticum
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INTRODUCTION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONREFERENCES |
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The F-strain M. gallisepticum vaccine, however, is not totally apathogenic and has been reported to infect M. gallisepticum-free birds and turkeys (Evans and Hafez, 1992; Ley et al., 1993). Once a bird is infected with M. gallisepticum, it is considered to be chronically infected for life (Brown et al., 1995). In a controlled study in biological isolation units, early vaccination with F-strain M. gallisepticum did not adversely affect EP (Branton et al., 1997). It has also been established that producers who have used F-strain M. gallisepticum for more than 2 decades have had no adverse effects on EP when F-strain M. gallisepticum vaccines have been given prelay (J. B. Self, vice president of operations, Cal Maine Foods Inc., Jackson, MS, personal communication). However, some field studies have determined that F-strain M. gallisepticum vaccination can reduce EP when compared with Mycoplasma-free birds (Carpenter et al.,1981; Mohammed et al., 1987; Branton et al., 1988). Burnham et al. (2002a) have also reported that F-strain M. gallisepticum inoculations at 12 wk of age may lead to a delay in onset of lay and a decrease in the total EP of laying hens housed in biological isolation units. More recently, apathogenic whole-cell live vaccines, including ts11-strain M. gallisepticum and 685-strain M. gallisepticum, have been licensed for use in layer chickens. These vaccines show virtually no bird-to-bird transmission, but have not been proven to displace wild-type M. gallisepticum (Kleven, 1998). Furthermore, these strains may not confer continued protection throughout lay as does the F-strain (Yoder, 1978, 1991; Mohammed et al., 1987).
More testing is needed to determine whether combinations of vaccines can lessen the impact of prelay F-strain M. gallisepticum vaccination. Therefore, the objective of the current study was to determine the effects of prelay ts11-strain M. gallisepticum inoculations and time-specific F-strain M. gallisepticum inoculation overlays administered during lay on the egg quality of commercial laying hens. In addition to an F-strain M. gallisepticum inoculation at the onset of lay (22 wk), an inoculation overlay at 45 wk was also included based on earlier findings by Branton et al. (1988), showing that EP was significantly reduced when 45-wk-old commercial layers were vaccinated with F-strain M. gallisepticum.
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MATERIALS AND METHODS |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONREFERENCES |
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Two trials were performed using Hy-Line W-36 pullets that were obtained at 1 d of age from a commercial source that was monitored and certified free of both M. gallisepticum and Mycoplasma synoviae (USDA-Animal and Plant Health Inspection Service-Veterinary Services, 2003). Chickens were vaccinated at 10 d of age for infectious bursal disease via the drinking water. At 5 wk of age, 20 randomly selected chickens were tested for antibodies to both M. gallisepticum and M. synoviae using both the serum plate agglutination (SPA) and the hem-agglutination-inhibition tests (Yoder, 1975). Swabs were obtained from the choanal cleft (Branton et al., 1984) and placed into tubes containing Frey’s broth medium (Frey et al., 1968) supplemented with an additional 0.15 thallium acetate and 106 IU of penicillin-G/mL. Tubes were incubated at 37°C for 30 d or until the phenol red indicator reaction occurred in the media. A sample from those that changed color was then inoculated onto Frey’s-based agar and incubated at 37°C. Colonies having a morphology suggestive of Mycoplasma species were examined by an agar plate fluorescent antibody (FA) test (Baas and Jasper, 1972) that used direct labeling of colonies stained with anti-F-strain M. gallisepticum polyclonal antibodies produced in rabbits and labeled with fluorescein isothiocyanate (Kleven, 1981).
Pullets were placed on clean dry litter in a conventional house until 10 wk of age. A daily artificial lighting schedule followed a 13 L:11 D cycle. One 75-W incandescent light bulb was used to illuminate each 8.4 m2 of floor space, providing a calculated intensity at bird level of 35.5 lx. Feed and water were provided for ad libitum consumption in each trial. At 10 wk of age, 11 pullets were randomly selected and placed in each of 16 negative-pressure fiberglass biological isolation units (1.16 m2). The units were housed in a previously described poultry disease isolation facility (Branton and Simmons, 1992). Hen numbers were reduced to 10 per unit at point of lay (22 wk of age) so that bird density was 0.116 m2/bird for the duration of each trial. At 18 wk of age, the length of the artificial lighting schedule was increased by 15 min/d until a cycle of 16 h and 15 min of light per 7 h and 45 min of dark was achieved. Chickens were maintained on that schedule through the remainder of each of the trials. For the entirety of each trial, chickens had ad libitum access to feed and water. Pullet and layer diets were formulated to meet or exceed NRC (1994) recommendations. Ingredient percentages and calculated analyses of the diets were as described by Burnham et al. (2002a). No medications were administered during either trial.
Treatments
Four experimental treatment groups were used. Each treatment group consisted of 4 isolation units containing 10 birds each, for a total of 40 birds per treatment group. Birds in treatment one (control) received no M. gallisepticum inoculation but were sham-inoculated via eye drop in the right eye at 10 wk of age with sterile Frey’s media. Treatment 2 contained birds that were eye drop-vaccinated in the right eye with ts11-strain M. gallisepticum at 10 wk of age (ts11/10). Birds belonging to treatment 3 received ts11-strain M. gallisepticum via eye drop in the right eye at 10 wk of age, followed by a wk 22 overlay vaccination via eye drop in the left eye with F-strain M. gallisepticum (ts11/10-F/22). Treatment 4 consisted of birds given ts11 strain M. gallisepticum at 10 wk of age via eye drop in the right eye followed by a wk 45 overlay vaccination of F-strain M. gallisepticum via eye drop in the left eye (ts11/10-F/45).
The ts11 vaccine titers for both trials were 1.0 x 1010 cfu/mL. For trial 1, F-strain M. gallisepticum titers were 3.0 x 1010 and 1.0 x 108 cfu/mL at wk 22 and 45, respectively. For trial 2, F-strain M. gallisepticum titers were 7.5 x 1011 cfu/mL for both inoculation overlays (wk 22 and 45). Differences in the F-strain M. gallisepticum titers between trials are normal and within ranges that are typically observed in the literature.
Data Collection and Egg Parameters Measured
All data collected from wk 23 through 44 were designated as belonging to age interval I, and all data collected from wk 45 through 57 were designated as belonging to interval II. Percentages of yolk weight, yolk moisture (YM), yolk lipid (YL), albumen weight (PA), and shell weight were determined in eggs at 24, 32, and 43 wk of age (interval I), and at 47 and 56 wk of age (interval II) in both trials 1 and 2. Beginning on wk 23 (when control group EP reached approximately 10%) in both trials, eggs were collected weekly from 23 through 44 wk (interval I) and weekly from 45 through 57 wk (interval II) to determine egg Haugh unit scores (HU). For determination of the above-mentioned parameters, a total of 10 eggs were collected from each replicate unit for an accurate estimate of each parameter (Buss, 1984). If fewer than 10 eggs were collected on a given day, the rest were collected the following day of the same week. Egg processing and determinations of HU and of fresh yolk and albumen weights were made on the same day that eggs were collected. Eggshell weight (dried shell plus membranes) was determined according to the procedure described by Brake et al. (1984). Egg component weights (egg yolk, albumen, and shell) were expressed as percentages of total egg weight. Haugh unit scores were determined by using a Model EQM egg quality management system (Technical Services and Supplies Limited, York, UK) according to the procedure of Branton et al. (1988).
Quantification of Yolk Moisture and Lipid Content
For YM determinations, 2-g samples of fresh yolk were dried in a commercial oven according to the procedure of Peebles et al. (1999). After samples were removed from the oven, they were allowed to cool for 30 min, and the dry weights were recorded. Yolk moisture was calculated as the difference between the fresh and dry weight of the sample and was expressed as a percentage of fresh sample weight. For YL determinations, 3-g samples of fresh yolk were used. Yolk lipid was extracted from the yolk by using chloroform:methanol (2:1 vol/vol) according to the procedure described by Bligh and Dryer (1959). Dried lipid samples were weighed and the expression of YL concentration was dry lipid sample weight as a percentage of total fresh yolk sample weight.
Statistical Analysis
A completely randomized experimental design, with trial as a block, was used. Data from wk 23 through 44 (interval I), and from wk 45 through 57 (interval II) were analyzed separately. The data from both trials were pooled and then analyzed together. Therefore, the results from both trials were not reported independently but were reported over both trials. Trial was considered as a random effect. All data within each age interval were subjected to a repeated measures analysis, because parameters were examined at multiple age periods in each age interval. In the first age interval, controls and those having had ts11/10 and ts11/10-F/22 inoculations were compared. In the second age interval, control, ts11/10, ts11/10-F/22, and ts11/10-F/45 groups were compared. Individual sample data within each of the replicate units were averaged before analysis. Least squares means were compared in the event of significant global effects (Steel and Torrie, 1980). Global effects and differences among least squares means were considered significant at P 
0.05. All data were analyzed by using the MIXED procedure of SAS software (SAS Institute, 2003).
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RESULTS AND DISCUSSION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONREFERENCES |
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Branton et al. (1997) reported that EP and other egg characteristic in birds inoculated with F-strain M. gallisepticum at 10 wk of age were not significantly different from controls. Conversely, in a more recent report by Burnham et al. (2002a) using birds inoculated at 12 wk of age, EP was reported to be significantly different in the F-strain-vaccinated birds compared with the controls. Burnham et al. (2002a) reported that onset of lay was delayed and that a significant decrease in EP occurred. It was also shown that hens inoculated with F-strain M. gallisepticum at 12 wk had fewer mature ovarian follicles and decreases in the magnal, isthmal, and vaginal portions of the reproductive tract at trial termination (60 wk) compared with F-strain M. gallisepticum-free hens (Burnham et al., 2002b). In further studies of yolk characteristics (Burnham et al., 2003), a decrease in YL was observed at 22 wk in the 12-wk F-strain-vaccinated birds, suggesting that F-strain vaccination may inhibit YL deposition at that time. Additionally, Branton et al. (1988) showed that F-strain M. gallisepticum given late in lay (wk 45) reduced subsequent EP. Because of these possible detrimental impacts of F-strain M. gallisepticum when given alone, the use of the ts11-strain as a prelay replacement for the F-strain and in conjunction with F-strain overlays during lay was investigated in the current study.
In the present study, no significant age or treatment main effects or age x treatment interactions were found for percentages of yolk moisture, yolk weight, or shell weight in either age interval examined. Furthermore, in a previous companion article, Vance et al. (2008) reported that despite increases in eggshell pimpling and egg blood spot incidences very late in production caused by the ts11/10-F/45 treatment, layer performance was not adversely affected by the ts11/10 inoculation alone or in conjunction with subsequent overlay inoculations of F-strain M. gallisepticum during lay. In an earlier study by Branton et al. (2000) using the ts11 vaccine, no significant effects were observed on EP, blood and meat spots, egg size, mortality, or HU scores. Furthermore, gross and histological changes were not observed upon necropsy. Therefore, because the egg and eggshell quality parameters selected for these trials reflect the functionality of the ovary and specific segments of the oviduct, the above results would suggest that the ovary and various segments of the oviduct were not compromised by the ts11 vaccine.
However, in the current study, although no significant age or treatment main effects or age x treatment interaction was observed for YL in interval II, a hen age x treatment interaction (P 0.05) was observed for YL (wk 24, 32, 43) in interval I (Table 1
). In comparison with controls, YL was significantly higher in the ts11/10 and ts11/10-F/22 vaccination regimens at wk 32. This result suggests that the inoculation of ts11 M. gallisepticum at 10 wk may increase YL in eggs up to 22 wk later. Mycoplasma gallisepticum has been cultured from the liver (Sahu and Olson, 1976) and periovarian region (Fabricant and Levine, 1963) of chickens, and the liver is considered to be the primary source of lipid production. Although the basis for the observed effect on YL is not clear, the synthesis, transport, and uptake of lipid in the liver, blood, and ovary, respectively, cannot be precluded as possible locations and means by which the ts11-strain M. gallisepticum organism may colonize and influence YL. Furthermore, these data imply that a subsequent inoculation of F-strain M. gallisepticum at 22 wk does not modify the effect of the ts11/10 treatment on YL at 32 wk.
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0.05) for PA (across 47 and 56 wk) in interval II (Table 2). Egg PA across wk 47 and 56 was significantly lower for birds in the ts11/10-F/22 treatment than for birds in the control and ts11/10-F/45 treatments, with those in the ts11/10 treatment being intermediate. For HU, there were no age or treatment main effects or age x treatment interactions in interval I, and there was no significant age main effect or age x treatment interaction in interval II. Nevertheless, a treatment main effect (P 0.05) was observed for HU scores (45 to 57 wk) in interval II (Table 2). In interval II, mean HU for the ts11/10 treatment group was significantly lower than that for the other 3 treatment groups. These results suggest that a prelay ts11-strain M. gallisepticum inoculation alone may lower albumen quality during postpeak lay.
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ACKNOWLEDGMENTS |
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FOOTNOTES |
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2 Use of trade names in this publication does not imply endorsement of these products by the Mississippi Agricultural and Forestry Experiment Station, or of similar ones not mentioned.
Received for publication March 4, 2008. Accepted for publication March 28, 2008.
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REFERENCES |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONREFERENCES |
|---|
Barbour, E. K., S. K. Hamadeh, and A. Eid. 2000. Infection and immunity in broiler chicken breeders vaccinated with a temperature-sensitive mutant of Mycoplasma gallisepticum and impact on performance of offspring. Poult. Sci. 79:1730–1735.
Bligh, E. G., and W. J. Dryer. 1959. A rapid method of total lipid extraction and purification. Can. J. Biochem. Physiol. 37:911–917.[Medline]
Brake, J., J. F. Ort, T. A. Carter, and W. R. Campbell. 1984. Effect of insect growth regulator CGA72662 (Larvadex®) on broiler breeder production, hatchability, and subsequent chick performance. Poult. Sci. 63:910–916.[Web of Science][Medline]
Branton, S. L., H. Gerlach, and S. H. Kleven. 1984. Mycoplasma gallisepticum isolation in layers. Poult. Sci. 63:1917–1919.[Web of Science][Medline]
Branton, S. L., B. D. Lott, J. W. Deaton, J. M. Hardin, and W. R. Maslin. 1988. F strain Mycoplasma gallisepticum vaccination of post-production-peak commercial Leghorns and its effect on egg and eggshell quality. Avian Dis. 32:304–307.[CrossRef][Web of Science][Medline]
Branton, S. L., B. D. Lott, J. D. May, W. R. Maslin, C. R. Boyle, and G. T. Pharr. 1997. The effects of F-strain Mycoplasma gallisepticum, Mycoplasma synoviae, and the dual infection in commercial layer chickens over a 44-week laying cycle when challenged before beginning of lay. I. Egg production and selected egg quality parameters. Avian Dis. 41:832–837.[CrossRef][Web of Science][Medline]
Branton, S. L., B. D. Lott, J. D. May, W. R. Maslin, G. T. Pharr, S. D. Bearson, S. D. Collier, and D. L. Boykin. 2000. The effects of ts-11 strain Mycoplasma gallisepticum vaccination in commercial layers on egg production and selected egg quality parameters. Avian Dis. 44:618–623.[CrossRef][Web of Science][Medline]
Branton, S. L., and J. D. Simmons. 1992. Design of a poultry disease isolation facility with programmable environmental control. Appl. Eng. Agric. 8:695–699.
Brown, J. E., S. L. Branton, and J. D. May. 1995. Effect of isolation and sanitation on the recovery of F-strain Mycoplasma gallisepticum from chronically infected hens held in biological isolation units. Avian Dis. 39:263–268.[CrossRef][Web of Science][Medline]
Burnham, M. R., S. L. Branton, E. D. Peebles, B. D. Lott, and P. D. Gerard. 2002a. Effects of F-strain Mycoplasma gallisepticum inoculation at twelve weeks of age on performance and egg characteristics of commercial egg-laying hens. Poult. Sci. 81:1478–1485.
Burnham, M. R., E. D. Peebles, S. L. Branton, M. S. Jones, P. D. Gerard, and W. R. Maslin. 2002b. Effects of F-strain Mycoplasma gallisepticum inoculation at twelve weeks of age on digestive and reproductive organ characteristics of commercial egg laying hens. Poult. Sci. 81:1884–1891.
Burnham, M. R., E. D. Peebles, S. L. Branton, D. V. Maurice, and P. D. Gerard. 2003. Effects of F-strain Mycoplasma gallisepticum inoculation at twelve weeks of age on egg yolk composition in commercial egg laying hens. Poult. Sci. 82:577–584.
Buss, E. G. 1984. Useful and nonuseful measurements in the genetic selection for improvement of eggshell quality. Pages 12–41 in Proc. 33rd Annu. Natl. Breeder’s Roundtable, St. Louis, MO. Poult. Breeders Am., Tucker, GA.
Carpenter, T. E., E. T. Mallinson, K. F. Miller, R. F. Gentry, and L. D. Schwartz. 1981. Vaccination with F-strain Mycoplasma gallisepticum to reduce production losses in layer chickens. Avian Dis. 25:404–409.[CrossRef][Web of Science][Medline]
Evans, R. D., and Y. S. Hafez. 1992. Evaluation of a Mycoplasma gallisepticum strain exhibiting reduced virulence for prevention and control of poultry mycoplasmosis. Avian Dis. 36:197–201.[CrossRef][Web of Science][Medline]
Fabricant, J., and P. P. Levine. 1963. Infection in young chickens for the prevention of egg transmission of Mycoplasma gallisepticum in breeders. Proc. 17th World Vet. Congr. 2:1469–1474.
Frey, M. C., R. P. Hanson, and D. P. Anderson. 1968. A medium for the isolation of avian Mycoplasma. Am. J. Vet. Res. 29:2164–2171.
Kleven, S. H. 1981. Transmissibility of the F-strain of Mycoplasma gallisepticum in leghorn chickens. Poult. Sci. 25:1005–1018.
Kleven, S. H. 1997. Mycoplasmosis. Pages 191–193 in Diseases of Poultry. 10th ed. B. W. Calnek, H. J. Barnes, C. W. Beard, W. M. Reid, and H. W. Yoder Jr., ed. Iowa State Univ. Press, Ames.
Kleven, S. H. 1998. Mycoplasmas in the etiology of multi factorial respiratory disease. Poult. Sci. 77:1146–1149.
Kleven, S. H., M. I. Khan, and R. Yamamoto. 1990. Fingerprinting of Mycoplasma gallisepticum strains isolated from multiple age layers vaccinated with live F-strain. Avian Dis. 34:984–990.[CrossRef][Web of Science][Medline]
Levisohn, S., and S. H. Kleven. 1981. Vaccination of chickens with nonpathogenic Mycoplasma gallisepticum as a means for displacement of pathogenic strains. Isr. J. Med. Sci. 17:669–673.[Web of Science][Medline]
Ley, D. H., A. P. Avakian, and J. E. Berkoff. 1993. Clinical Mycoplasma gallisepticum infections in multiplier brooders and meat turkeys caused by F strain: identification by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, restricted endonuclease analysis, and the polymerase chain reaction. Avian Dis. 37:854–862.[CrossRef][Web of Science][Medline]
Mohammed, H. O., T. E. Carpenter, and R. Yamamoto. 1987. Economic impact of Mycoplasma gallisepticum and M. synoviae in commercial layer flocks. Avian Dis. 31:477–482.[CrossRef][Web of Science][Medline]
NRC. 1994. Nutrient Requirements of Poultry. 9th rev. ed. Natl. Acad. Press, Washington, DC.
Peebles, E. D., L. Li, S. Miller, T. Pansky, S. Whitmarsh, M. A. Latour, and P. D. Gerard. 1999. Embryo and yolk compositional relationships in broiler hatching eggs during incubation. Poult. Sci. 78:1435–1442.
Sahu, S. P., and N. O. Olson. 1976. Use of the agar-gel precipitin test to evaluate broiler breeder and commercial layer flocks for Mycoplasma gallisepticum infection. Avian Dis. 20:563–573.[CrossRef][Web of Science][Medline]
SAS Institute. 2003. SAS Proprietary Software Release 9.1. SAS Inst. Inc., Cary, NC.
Steel, R. G. D., and J. H. Torrie. 1980. Principles and Procedures of Statistics. A Biometrical Approach. 2nd ed. McGraw-Hill, New York, NY.
USDA-Animal and Plant Health Inspection Service-Veterinary Services. 2003. National poultry improvement plan and auxiliary provisions. Fed. Regist. 68:28169–28175.
Vance, A. M., S. L. Branton, S. D. Collier, P. D. Gerard, and E. D. Peebles. 2008. Effects of time specific F-strain Mycoplasma gallisepticum inoculation overlays on pre-lay ts11-strain Mycoplasma gallisepticum inoculation on performance characteristics of commercial laying hens. Poult. Sci. 87:655–660.
Yoder, H. W., Jr. 1975. Mycoplasmosis. Pages 109–117 in Isolation and Identification of Avian Pathogens. Am. Assoc. of Avian Pathol., College Station, TX.
Yoder, H. W., Jr. 1978. Mycoplasma gallisepticum infections. Pages 236–250 in Diseases of Poultry. 7th ed. M. S. Hofstad, B. W. Calnek, C. F. Helmboldt, W. M. Reid, and H. W. Yoder Jr., ed. Iowa State Univ. Press, Ames.
Yoder, H. W., Jr. 1991. Mycoplasmosis. Pages 198–212 in Diseases of Poultry. 9th ed. B. W. Calnek, H. J. Barnes, C. W. Beard, W. M. Reid, and H. W. Yoder Jr., ed. Iowa State Univ. Press, Ames.
Yoder, H. W., Jr., S. R. Hopkins, and B. W. Mitchell. 1984. Mycoplasma gallisepticum oil-emulsion bacterins for protection against airsacculitis in broilers. Avian Dis. 28:224–234.[CrossRef][Web of Science][Medline]
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