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QUALITY PARAMETERS IN EGGS OF LAYER CROSS Hisex Brown AS AFFECTED BY THE OVIPOSITION TIME
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The effect of the age and oviposition time on yolk cholesterol content and total yolk cholesterol was investigated in laying hens. Three hundred , twenty-two weeks old, ISA-Brown hens were raised in layer battery cages under the confined system for 16 weeks. Of which, oviposition time was recorded in the morning and afternoon egg collections. These egg samples were randomly collected nine times at a one-week interval based on hen’s age. At each time, fifteen eggs laid in the morning and a similar number laid late in the afternoon were collected. Yolk samples were prepared followed by saponification and extraction of lipids. Yolk cholesterol content was determined using a spectrophotometer. Total yolk cholesterol was then calculated. The age of laying hens showed significant effect; as the age progressed, yolk cholesterol content was decreased (14.44 ˗ 14.32 mg/g yolk) whereas, total yolk cholesterol was increased (178.04 ˗ 214.75 mg/egg). The oviposition time showed the significant treatment effect as reflected by the lower yolk cholesterol content of morning eggs (12.53 mg/g yolk) compared to afternoon eggs (16.23 mg/g yolk). Furthermore, morning eggs had significantly lower total yolk cholesterol (176.63 mg/egg) than afternoon eggs (221.14 mg/egg). Hence, morning eggs are superior to meet the interest of table egg producers and consumer demand
In Australia and other parts of the world, table eggs with uniform brown eggshell color are well regarded by consumers. Brown
eggshell color has been positively correlated with certain egg characteristics such as shell strength and egg specific gravity,
along with specific antibacterial functions. In the current study, the effect of hen oviposition time, flock age, and egg
position in-clutch on the intensity of brown eggshell color was studied in commercial laying hens. The collected eggs were
processed to measure egg weight, shell reflectivity, shell color (L*a*b*), quantification of protoporphyrin IX (PP IX), and
shell thickness. Hen oviposition time had a statistically significant effect (P < 0.05) on egg weight, L*a*b*, amount of PP IX, and shell thickness. L* increased from 59.72 in the first half hour after
lights on to 61.67 6 hours later, and PP IX per gram of eggshell decreased from 1.32×10−7 mM to 1.26×10−7 mM. Flock age had a significant effect on egg weight, L*a*b*, shell reflectivity, PP IX, and shell thickness. The mean egg
weight increased from 55.4 g at 25 wk of flock age to 63.3 g at 75 wk of flock age. PP IX per gram of eggshell was 1.45×10−7 mM at 25 wk and declined to 1.31×10−7 mM at 75 wk of flock age. Individual hen clutch length was highly variable, ranging from 22 to 123 eggs in a single clutch.
Egg position in a clutch had a significant effect on all egg quality variables measured; however, the R2 values for each variable measured were low. The eggshell color declined to a greater extent with increasing position in a
clutch for long clutches compared with short and medium clutches. In conclusion, hen oviposition time affected brown eggshell
color with darker brown eggs laid early in the d and lighter colored brown eggs laid later in the morning. The intensity of
brown color decreased with flock age, and egg position in-clutch had relatively little effect on brown eggshell color.
The effect of age and collection time on egg composition and eggshell quality was studied in an experiment with Hisex Brown laying hens in three periods during a laying cycle (20-24, 38-42 and 56-60 weeks of age). Eggs were collected daily at 6:00, 10:00 and 14:00 h. At each age range, every two weeks (3 times per age range) eggs were collected for egg quality analyses (total 1486 eggs). Egg weight increased with hen's age and the heaviest eggs were collected at 6:00. The same trends were found in yolk weight. Albumen weight grew slower than yolk weight and the effect of oviposition time on albumen weight was ambiguous. Deviations in increase of yolk and albumen weight were expressed in significant interactions for yolk: albumen ratio. In addition, significant interactions of age and oviposition time for eggshell weight, index, thickness and colour were found. High correlations were determined between eggshell thickness and eggshell index (0.85), eggshell weight (0.75), eggshell strength and eggshell index (0.52).
Hourly oviposition (egg laying) time and egg weight were studied over 24 hr in first-cycle commercial hens at 33 and 76 wk
of age to gain better insight into profitable egg gathering practices. Eggs from two flocks (60,000 birds each) of White Leghorn
hybrids were sampled directly of the egg belts in adjacent, similar houses. Hourly plots of oviposition times indicated that
50% of a young flocks eggs are laid within 13 hr after the beginning of the dark cycle, while in older flocks oviposition
is delayed another 30 to 60 min. Linear regression of daily egg weights showed that eggs are consistently heavier in the morning
and decline 2 to 9 g/egg/day between 0500 and 1800 hr. Coupled with other knowledge, including the daily change in shell integrity,
the findings herein have applications for the mechanical gathering of eggs in a commercial setting to minimize egg breakage
and increase the number of gradable eggs.
A total of 7,273 eggs laid by 270 Hisex Brown hens for 31 days, beginning at 29 weeks of age, was identified individually. Each egg was recorded for time of oviposition, and egg and shell weights were measured. The average time of oviposition of all eggs was 0940 ± 0226 hr (mean ± SD) and the average egg weight and shell weight were 55.1 ± 3.6 and 5.24 ±.43 g, respectively. Eggs laid early in the morning were heavier than those laid later during the day. Egg weight decreased thereafter and remained relatively constant after 0930 hr. Shell weights decreased during the morning and gradually increased again in the afternoon. Hens with higher rates of production tended to lay earlier and showed less variation in time of oviposition. No consistent relationship was found between production rate and egg weight or shell weight. A positive correlation (r = .54) was found between egg weight and shell weight.
The objective of this study was to evaluate the effects of storage temperature and time on the quality parameters of eggs from laying hens at peak production. A total of 576 eggs were obtained from Lohmann Light-Brown hens, which were collected 3 times when the hens were 26, 27, and 28 weeks old. The fresh eggs were collected and measured within 2 h of being laid. Samples of 48 eggs each were stored in chambers for 2, 5, or 10 d inside a refrigerator (), at room temperature (), and at a high temperature (). As the storage temperature and time increased, egg weight, percentage of albumen, Haugh unit (HU), and yolk color significantly (p
In this experiment with three pure chicken breeds the effect of oviposition on egg quality parameters was investigated. Laying hens of the Brown Leghorn, Oravka and Brahma from 20 to 64 weeks of age were housed in pens with deep litter. The collection time was at 6.00, 10.00 and 14.00 h. Eggs were gathered at the start, middle and end of the laying period. In Brown Leghorn time of oviposition had no significant (P>0.05) affected yolk percentage, yolk index and egg weight. However, in shell thickness, albumen index and Haugh Units we detected significant (P<0.05) differences among collection times. In Oravka hens, the time of oviposition had no significant (P>0.05) effect on egg weight, albumen index and Haugh Units. We recorded significantly (P≤ 0.05) higher value of shell thickness in 06:00 h in comparison with 10:00 and 14:00 h, but other eggshell quality parameters as shell percentage and shell strength were no significantly (P>0.05) affected in the eggs laid at 6:00, 10:00 and 14:00 h. In Brahma, the egg weight, shell percentage, shell thickness and shell strength were significant (P<0.05) affected by time of oviposition.
This research was carried out to determine the relationships among egg quality characteristics in post molt eggs of Brown layer (H and N Brown Nick) and White layer (Hy-Lme W-36) with used non feed-withdrawal programs (BB: Barley Based, WB: Wheat Bran Based and OB: Oat Based) and Feed Withdrawal method (FW). Eggs for analyses were sampled from 76-93 weeks in second production. About 160 eggs were sampled for each week and it lasted 16 weeks. In total, 2,560 eggs were examined. There were significant (p<0.01) positive correlation between egg weight and albumen height and shell thickness and shape index. No significant correlation between specific gravity and albumen height and shape index were determined. There were significant (p<0.01) correlation between egg weight and specific gravity and albumen height for both genotypes (-0.384 and 0.110 in white layers, -0.329 and 0.169 in brown layers, respectively. There were no significant correlation between specific gravity and albumen height for both genotypes. There were significant (p<0.01) positive correlation between specific gravity and albumen height for BB and OB programs but no significant correlation between specific gravity and albumen height for FW and WB programs were found.
Two experiments were carried out to investigate the effect of the time of oviposition on egg quality characteristics in two different housing systems (cages vs. litter). ISA brown hens from 20 to 64 weeks of age were housed in battery cages (550 cm 2 /hen, 19 526 laying hens in the house) and on deep litter (7 hen/m 2 , 4 652 laying hens in the house). In both houses, eggs were collected daily at three oviposition times 06:00, 10:00 and 14:00 h. Every four weeks, 90 eggs for each house (30 eggs for each oviposition time) were used for egg quality assessment. The results indicated that in cages the highest percentages (P ≤ 0.001) of normal (74.47%), non-standard (0.85%) and cracked (1.80%) eggs were laid in the early morning (06:00 h). On deep litter, however, the highest percentages (P ≤ 0.05) of normal sound eggs were produced at 10:00 h (35.43%) and at 14:00 h (33.03%). In the cage system, the heaviest eggs (63.01 g) were laid in the early morning (06:00 h) and the highest shell percentage (10.33%) was in eggs laid in the afternoon and also at 10:00 h (10.31%). On the other hand, in the litter housing system, the time of oviposition had no significant effect on egg weight and eggshell quality characteristics except for shell thickness. Morning eggs had greater shell thickness (0.398 mm) than afternoon eggs (0.390 mm). In cages and on litter, statistically significant differences in albumen height, albumen index and Haugh Units were observed between early morning eggs and afternoon eggs and data showed a pattern of relatively higher albumen quality for eggs collected in the afternoon in both systems.
This investigation was carried out to study mechanical eggshell traits (weight, specific gravity, eggshell thickness and eggshell breaking strength) and ultrastructural properties from layer breeder hens at different ages (25, 47 and 61 weeks). The present results showed that the brown eggshell had significantly higher specific gravity, shell thickness and breaking strength compared to white eggshell. Concerning breeder flock age, it could be noticed that the age of hen significantly affected mechanical eggshell traits, where specific gravity, shell thickness and breaking strength decreased significantly as the breeder age was advance. With respect to eggshell ultrastructural properties, the brown eggshell had significantly higher effective thickness (palisade %) compared to white ones. Opposite trend was observed for relative cap thickness. With regard to layer breeder flock age effect, the results indicated that the effective thickness (palisade %) was significantly decreased as the layer breeder flock age increased. Conversely, the relative cap thickness was increased with age increased. With respect to confluence trait, the present results observed that both brown and white eggs owned shells with similar values of confluence. Significant difference observed between strains regarding fusion (early or late) trait. Type B's, type A's and alignment traits in eggshell produced from older breeders was significantly higher that of younger breeders.
Stress and diseases have the potential to influence the deposition of eggshell pigmentation during egg formation. Therefore, defining the shell color of eggs on a daily basis could be a representative method for monitoring stress or health status of a flock and maintaining good performance. A novel way of measuring eggshell color based on visible-near infrared transmission spectroscopy transmission spectra was defined: the transmission color value (TCV). The TCV was calculated as the ratio between the transmission at 643 nm (maximum absorbance of the pigmentation molecule protoporphyrin IX) and the transmission at 610 nm (a reference wavelength). Experiments were carried out to investigate the relevance of TCV for monitoring flock stress and health or even anticipating any factors unfavorable to performance. In 2 small experimental flocks, deliberate heat stress challenges were applied. A medium-scale experimental flock in an aviary was monitored on a daily basis during the whole productive period. From the deliberate heat stress challenges, it was seen that stress had a significant effect on eggshell pigmentation. This observation was confirmed in a daily monitored flock, in which, for example, an infectious bronchitis infection occurred. These stress situations were quickly reflected by an increased TCV value: more transmission due to less pigmentation and hence less absorbance at the pigmentation wavelength. Furthermore, for the observed problems in the daily monitoring, the TCV value signaled the problem earlier (4 d) than the average egg weight or even signaled when the other parameters did not signal anything. Measuring the TCV of all eggs produced on a daily basis provides relevant information on the stress or health status of a flock of brown layers. This could be used as an early detection of stress situations or emerging diseases, even before important quality and health damage can occur.
There are a number of specialty shell eggs available to consumers in the US retail market. A survey consisting of white and brown large shell eggs with various production and nutritional differences (traditional, cage-free, free-roaming, pasteurized, nutritionally enhanced, and fertile) was conducted to determine if physical quality and compositional differences exist. Identical brands of eggs were purchased from the same retail outlets on 3 occasions (replicates) in a single city. The average range of time from processing to purchase for all eggs was 7.67 to 25.33 d, with traditional white eggs in retail having the shortest time. Haugh unit values ranged from 66.67 (cage-free, docosahexaenoic acid, and n-3 enhanced) to 84.42 (traditional white). Albumen height followed a similar pattern. Egg weight was greater for brown eggs (61.12 vs. 58.85 g). Brown eggs also had greater static compression shell strength than white eggs (4,130.61 vs. 3,690.31 g force). Vitelline membrane strength was greatest for traditional brown eggs (2.24 g force). Percentage of total solids and crude fat was greatest in the cage-free, n-3-enhanced white eggs (25.07 and 11.71%, respectively). Although significant differences were found between white and brown shell eggs and production methods, average values for quality attributes varied without one egg type consistently maintaining the highest or lowest values.
An experiment was conducted to determine the effect of time of oviposition, generally representing different positions in the normal egg laying sequence, on egg weight loss during storage and incubation, and on fertility and fertile hatchability of eggs from mid-lay (42 wk) and old (67 wk) broiler breeders. A total of 1,800 eggs (900 eggs per flock age) were collected during 10 consecutive days between 0830 and 1830 h each day. The eggs were individually marked, weighed, and stored for 1 to 10 d before incubation was initiated. Egg weight remained less from collection through incubation for eggs from the mid-lay flock than those from the old flock. Fresh weight of early laid (first-in-sequence; C1) eggs was significantly greater than that for the middle-of-day laid (mid-sequence; Cs), or late-in-day laid eggs (terminal-in-sequence; Ct). Percentage of egg weight loss during storage did not differ significantly between the mid-lay and old flocks but percentage of weight loss in the mid-lay flock was greater during incubation. Egg weight loss during storage of eggs from the middle-of-day laid (Cs) eggs was significantly greater than for early laid (C1) eggs, which was greater than for the late-in-day laid (Ct) eggs. Fertility was significantly decreased due to flock age but not due to oviposition time. Fertile hatchability was also significantly decreased due to flock age, but there was no significant effect of oviposition time. Early and late dead embryos increased with flock age, but there was no significant effect of oviposition time. It was concluded that there was no effect of oviposition time on fertility or fertile hatchability even though there were significant differences in egg weight and egg weight loss during storage due to oviposition time.
Phosphorus is an essential nutrient involved in most metabolic processes. Most of the interest in Ca metabolism relates to eggshell formation. Although the eggshell is composed of Ca carbonate, metabolism of both Ca and P is closely related such that a deficiency in one can interfere with proper utilization of the other. To understand Ca and P metabolism properly, modeling can be of paramount importance. A new dynamic and mechanistic model of P and Ca metabolism in layers has been developed to simulate diurnal changes in Ca and P and the hourly requirement of the layer for those minerals. The model consists of 8 state variables representing Ca and P pools in the crop, stomachs, plasma, and bone. The flow equations are described by Michaelis-Menten or mass action forms. An experiment that measured Ca and P uptake in layers fed different Ca concentrations during shell-forming days was used for model evaluation. The experiment showed that Ca retained in body and egg decreased from 62.5 to 50.5% of Ca intake when the Ca in diet was increased from 25 to 45 mg/g of feed. The model simulations were in agreement with the trend. Predictions of Ca retention in bone and egg were 63.2, 56.1, and 55.3% for low, medium, and high dietary Ca concentrations. The experimental results showed that P retention in body and egg increased significantly from 11.5% of absorbable P intake at the lowest Ca inclusion concentration to 24.1% at the highest. The model also predicted an increase in P retention in bone and egg from 8.4 to 25.4% of absorbable P intake at the lowest and highest concentration of Ca inclusion, respectively. The advantage of the model is that absorption and utilization can be monitored on an hourly basis and that adjustments can be made accordingly. The model successfully showed how the availability of one mineral affects the utilization of the other and is a useful tool to evaluate feeding strategies aimed at reducing P excretion to the environment in poultry manure.
Eggs were collected from 1 day of production of Hy-Line® W36 commercial egg production hens 55 wk old. Also, eggs were collected from 1 day of production of Arbor Acres broiler breeder hens when they were 40 and 55 wk of age. The eggs were immediately weighed (EW) after collection and specific gravity (ESG) determined. The eggs were then broken and the contents removed. Shells were washed, air dried, and weighed. The weights of shells (ESW) were calculated using the following formulas: Broiler breeder ESW=1.9128×EW−1.9741EWESG and layer ESW=1.9140×EW−1.9754EWESG. Shell density (BSD) was calculated using a modification of this formula.
Egg weights of both commercial layers and broiler breeders were heaviest in the early morning. There was a steady decline in EW until 1545 h; EW increased thereafter. Specific gravity of eggs was highest in the morning, declined until 1245 h, and then increased thereafter. Shell weight was also highest in the morning, declined until 1245 h, and then increased thereafter. The calculated and measured ESW were highly correlated. The ESD was 2.147 and 2.160 for the commercial layers and broiler breeders, respectively.
Two experiments were conducted to investigate egg weight, fertility, hatchability, and embryonic mortality in relation to time of oviposition of young and old broiler breeder flocks. In experiment 1, eggs were collected from 2 flocks (34 and 59 wk) for 2 d at hourly intervals between 0700 and 1900 h. Most eggs were laid between 0700 and 1300 h, but eggs were laid later in the day by the old flock. Weights of early laid (C1) eggs were significantly greater than middle laid (Cs) and the late laid (Ct) eggs in the young flock, whereas late laid eggs (Ct) were significantly smaller than early laid (C1) and middle laid (Cs) eggs in the old flock. In experiment 2, eggs from experiment 1 were categorized as early laid first-in-sequence (C1) eggs (0700 to 0800 h), the mid-sequence (Cs) eggs (0900 to 1200 h), and the late laid terminal-in-sequence (Ct) eggs (1300 to 1700 h). These eggs were incubated to determine fertility, hatchability, and stage of embryonic mortality relative to oviposition time and flock age. Fertility declined with flock age, but there were no differences due to time of oviposition. There were no differences in hatchability of fertile eggs or embryonic mortality relative to time of oviposition (sequence position) or flock age. These results suggested that although there were differences in egg weight among eggs at different times of the day (different sequence positions), there were no differences in fertility, fertile hatchability, or embryonic mortality in naturally mated broiler breeders.
The relationship of oviposition time (OT) to egg weight, specific gravity, and shell weight was examined in two trials. Trial
1 was at 38 and 39 weeks of age, while Trial 2 was conducted at 44 weeks of age. Two commercial strains were utilized. The
feeding time (FT) was 0800 hr in Trial 1 and either 0800 or 1300 hr in Trial 2.
Egg weight was greatest for eggs laid before 0900 hr OT in Trial 1. Specific gravity was highest for eggs laid between 1500
to 1900 hr and lowest from 0900 to 1300 hr OT. Shell weight was greatest for 1900 to 0700 hr OT and lowest at 0900 to 1300
hr OT.
A significant OT × FT interaction occurred for all parameters in Trial 2, which indicated a differential diurnal distribution
due to different FT. No overall change in egg weight or specific gravity was observed. Shell weight was increased significantly
by the 1300 hr FT when compared to the 0800 hr FT.
It was concluded that there is a diurnal variation in egg weight, specific gravity, and shell weight exhibited by limit-fed
broiler breeders and this pattern can be modified somewhat by different FT.
The purposes of this study were to determine the effects of oviposition time on egg quality and to examine the possibility of estimating egg shell weight using a formula. The interactions in some egg quality measurements were also studied. During the experiment 80 white and 64 brown layers were housed in cages and fed with a standard layer ration. The birds were given 17 hours of light per day throughout the experiment. Egg quality was checked four times with two week intervals. At each check, eggs were collected at 09.00, 12.00 and 15.00, on consecutive days. Egg weight (EW), egg specific gravity (ESG) and shell weight (SW) were measured, and then shell ration (SR) and shell weight per unit surface area (SWUSA) were calculated. In addition, the SW was estimated by two formulae using EW and ESG. The data from white and brown layers were analysed separately. The effects of oviposition time and age of hens were tested with variance analysis. The correlation coefficients between quality measurements were determined. The effect of age was not significant (p>0.05). Collection time had a significant (p<0.05) effect on the EW of white and brown layers. For the two groups, the heaviest EWs were determined at the first collection time, and the lightest EWs at the last time. Although the measured SW was not affected by the collection time, it was highest at the first collection. Significant correlations were detected between measured and calculated SW (r between .6612 and .8521, p<0.01 overall). The ESG was more closely correlated with SR and SWUSA than with SW. In addition, negative correlations were found between EW and ESG as well as with SR.
To elucidate the relationship of the position of egg in sequence to the quality of eggshell, the strength and thickness of shells of eggs in various lengths of sequences was measured. The strength of eggshells was not different between the first and second eggs in 2-egg sequences, but a higher strength was observed in the first and last eggs of 3-egg sequences compared with that of the second egg. In 4- and 5-egg sequences, the strength of eggshells tended to be higher for the first and last eggs than for the last egg but one. No difference was found in the thickness of eggshells between the first and second eggs in 2-egg sequences, but in sequences of 3 eggs or more the eggshell of the first and last eggs was thicker than that of the last egg but one. The strength and thickness of eggshells of the first and last eggs tended to be higher as the sequence length increased. The results indicate that eggshell quality may change in relation to the position of egg within a sequence and the sequence length in laying hens.
Eggshell quality was studied in three groups of Issa brown hens, from 73 to 78 weeks of age. Group 1 (control) received a basal diet with 3,8 % Ca and 0,35 % available P, in which pulverized limestone (particle size 0,02 mm) was the main source of Ca. The other two groups of hens were fed diets of the same composition but differing in the supplemented limestone particle size. In group 2 and 3 60 % of the pulverized limestone was substituted with a granular form, of particle size 1,10-1,40 mm. and 1,42-2,80 mm respectively. Eggs for examina-tion were collected at three periods of time: 7-9 hours, 11-13 hours and 15-17 hours. There were significant effects of particle size and oviposition time on eggshell quality. Egg mass and shell deformation decreased, while shell breaking force, shell thickness and shell mass increased with increasing oviposition time. At the afternoon period of laying, significantly higher (p<O,05) breaking force (5,0 kg) and lower shell deformation (21,9/1) were obtained in eggs of hens fed on the diet incorporating the granular form of limestone (particle size 1,10-1,40 mm) than eggs of hens fed only putverized limestone. It was shown that there are possibilities for improving eggshell quality, in older hens, by a combination of pulverized and granular limestone in the diet, as a source of calcium.
1. Egg‐shell colour, egg specific gravity, shell thickness and egg weight were determined for 2080 eggs from three varieties of the Vasca, a Spanish brown‐egg‐laying hen.2. Intermediate, positive and significant (P < 0·01) correlation coefficients were found between egg‐shell colour and specific gravity (0·25), or shell thickness (0·21). There was a very high (0·84), significant (P < 0·01) correlation between the measures of shell strength.3. Shell thickness was accurately predicted with both specific gravity and egg weight as independent variables (determination coefficient 0·74); eggshell colour did not explain any further variation.4. All traits showed considerable departure from normality in the form of negative kurtosis (shell colour and specific gravity), positive kurtosis (shell thickness and egg weight), negative skewness (shell thickness) or positive skewness (egg weight).5. Egg‐shell colour, specific gravity and shell thickness were less in July, in old birds and in eggs laid in the morning. Differences in egg quality traits between the three varieties were not significant.
1. Effects of two housing systems (cages vs outdoor) on external and internal egg characteristics were investigated. 2. In total 785 eggs from three different lines in cages and 268 eggs from outdoor-housed layers were examined for egg weight, albumen, yolk and shell content, albumen height and pH, and albumen and yolk dry matter content. 3. Interactions between layer age and housing systems were found for egg weight, eggshell content, albumen height, albumen pH, and dry matter content of the albumen and yolk. This was mainly due to the greater variation with age in the outdoor layers, compared to the caged layers. 4. Irrespective of age eggs from outdoor layers were relatively broader than eggs from the caged layers. Yolk colour was considerably darker in the outdoor group (11.0 vs 9.3). 5. We concluded that it is more difficult to maintain constant external and internal egg quality in an outdoor housing system than in a battery cage system. Factors that determine the greater fluctuations in internal egg quality need to be investigated.
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