Effects of Supplementing Selenium-Enriched Cardamine violifolia to Laying Hens on Egg Quality and Yolk Antioxidant Capacity during Storage at 4 °C and 25 °C.

Oxidative stress occurs in the process of egg storage. Antioxidants as feed additives can enhance egg quality and extend the shelf life of eggs. Selenium-enriched Cardamine violifolia (SEC) has strongly antioxidant properties. The objective of this study was to assess the effects of dietary supplementation with SEC on egg quality and the yolk antioxidant capacity of eggs stored at 4 °C and 25 °C. Four hundred fifty 65-week-old, Roman hens that were similar in laying rate (90.79 ± 1.69%) and body weight (2.19 ± 0.23 kg) were divided into 5 groups. The birds were fed diets supplemented with 0 mg/kg selenium (Se) (CON), 0.3 mg/kg Se from sodium selenite (SS), 0.3 mg/kg Se from Se-enriched yeast (SEY), 0.3 mg/kg Se for selenium-enriched Cardamine violifolia (SEC) or 0.3 mg/kg Se from Se-enriched Cardamine violifolia and 0.3 mg/kg Se from Se-enriched yeast (SEC + SEY) for 8 weeks. The eggs were collected on the 8th week and were analyzed for egg quality and oxidative stability of yolk during storage at 4 °C or 25 °C for 0, 2, 4, or 6 weeks. Dietary SEC and SEC + SEY supplementation increased the Haugh unit (HU) and albumen foam stability in eggs stored at 4 °C and 25 °C (p < 0.05). SS and SEC supplementation increased the yolk index in eggs stored at 25 °C (p < 0.05). SEC or SEC + SEY slowed down an increase in albumen pH and gel firmness in eggs stored at 4 °C and 25 °C (p < 0.05). Moreover, SEC or SEC + SEY alleviated the increase in malonaldehyde (MDA), and the decrease in total antioxidant capacity (T-AOC) level and total superoxide dismutase (T-SOD) activity in yolks stored at 4 °C and 25 °C (p < 0.05). These results indicate that SEC mitigated egg quality loss and improved the antioxidant capacity of yolks during storage. SEC supplementation would be advantageous to extend the shelf life of eggs.

Impact of broiler breeder hens' age and egg storage on egg quality, embryonic development, and hatching traits of FUNAAB-alpha chickens.

This study aimed to determine the impact of the age of breeder hens and egg storage on egg quality, embryonic development, hatching events and chick quality in FUNAAB-alpha chickens. The study involved the use of 500 hatching eggs each collected from 32-wk and 60-wk-old of FUNAAB-alpha broiler breeder hens at the Animal Breeding and Genetic Unit of the Federal University of Agriculture, Abeokuta, Nigeria and subjected to 5 storage periods (0, 3, 7, 11, and 15 d). The quality traits of the eggs were recorded and incubated using the conventional protocol. Data were collected on the internal and external egg characteristics, embryonic development, hatching events, and chick quality. The data collected were laid out in 2 by 5 factorial design. The results showed that eggs from 32-wk-old breeder hens had higher albumen height and Haugh unit (HU) value than those from 60-wk-old breeders. The albumen height and HU decreased progressively with storage length in the 2 age groups. Extended storage duration linearly increased (P < 0.01) egg weight loss and decreased (P < 0.01) yolk height. The eggs from both breeder ages had increasing blastodermal diameters at oviposition up until d 11 of storage but decreased on d 15 of storage in eggs from 32 wk breeders. Eggs of 32-wk-old FUNAAB-alpha breeder hens had larger diameters at oviposition compared with 60-wk-old breeders. The chicks from 60-wk breeder had late internal pipping (469.06 h), early external pipping (474.46 h) and a shorter time lag between both pips (9.00 h) compared to chicks from 32 wk breeder. The highest fertility was recorded in eggs stored for 3 d (80.7% and 79.6%), while the lowest fertility was in eggs stored for 15 d (53.4% and 47.7%) in both 32-wk and 60-wk-old breeders, respectively. Chicks from young breeder hens stored for 3 d had better quality scores (100%) compared to 0, 7, 11, and 15-d storage duration and in 60-wk-old breeders across all storage duration. It was concluded that both egg storage duration and age of breeder affected egg quality, hatching events and hatchling quality of FUNAAB-alpha chickens and the interaction effects of both factors was recorded for some of these traits. However, extended storage beyond 7 d had a larger negative impact on egg quality and hatchability of eggs from an old breeder (60 wk) than on eggs of a young breeder (32 wk).

Rapid egg cooling rate after oviposition influences the embryonic development, hatchability, and hatch time of young and old broiler hatching eggs.

This study investigated the effect of the egg cooling profile after oviposition on blastoderm development, embryonic mortality, hatchability, and hatch time of broiler hatching eggs from young and old breeder flocks. Hatching eggs were obtained from commercial Ross 308 broiler breeders at 28 wk (young) and 64 wk (old) of age. A total of 3,150 eggs laid within a 15-min period were collected and randomly assigned to 2 temperature-controlled chambers in both flocks. The eggshell temperature (EST) was cooled to 24°C either within 6 h (control) or 45 min (rapid). After the EST reached 16°C in the chambers in all groups, eggs were transported to the commercial hatchery. Eggs were stored for 6 d at 16°C and 75% relative humidity. The development of the blastoderm in sampled eggs (25 embryos in each batch) was determined immediately after egg collection and before transport to the hatchery (after cooling) on a farm in each flock. At each flock age, there were 5 replicate trays of 150 eggs per egg cooling treatment set in a single commercial incubator. The results showed that the embryonic developmental stage was retarded by rapid cooling and by the younger flock. A flock age × cooling rate interaction was observed for fertile hatchability and early and late embryonic mortality (P < 0.001). In the young flock eggs, the fertile hatchability was significantly lower in the rapid than in the control cooling treatment (88.7 vs. 92.8%) due to higher early and late embryonic mortality, whereas rapid cooling reduced early embryonic mortality (P < 0.01) and numerically increased the fertile hatchability (88.7 vs. 87.2%) in the old flock eggs. Hatch time was affected by the cooling treatment. The average hatch time was delayed by 3 h by rapid cooling (486.2 vs. 489.2 h) after oviposition compared with the control. This study showed that cooling the EST to 24°C within 45 min (rapid cooling) compared to 6 h (control) after laying retarded the blastoderm developmental stage and hatch time of eggs from both young and old broiler breeder flocks. This was apparently detrimental for the young flock as indicated by the higher early and late embryonic mortality but beneficial for the old flock due to the lower early embryonic mortality. The differences in hatchability between young and old flock eggs resulting from a rapid cooling rate might depend on the differences in embryonic development at oviposition.

Effects of age and eggshell thickness on the hatching results of stored broiler breeder eggs.

The present study was conducted to determine the effects of breeder age and eggshell thickness on the hatching results of broiler breeders. A total of 3000 eggs were collected from three flocks at different ages, viz., 27 (young), 48 (middle-aged) and 65 (old) weeks. Eggs were individually weighed and eggshell thicknesses were determined using an ultrasound gauge. The eggs of each age group were classified as thin-, medium- or thick-shelled and stored for 7 days at 18°C and 60% relative humidity prior to incubation. Total egg weight loss during storage and incubation was higher in middle-aged (48 weeks old) flock eggs (11.46%) than in young (10.14%) and old (10.37%) flock eggs. Hatchability was significantly lower in the eggs of the old flock than of the other flocks. The highest hatchability (70.6%) was observed in the young flock. Eggs with thick shells better tolerated the detrimental effects of storage and more eggs remained fertile than amongst the medium- and thin-shelled eggs. The overall hatchability of the old flock was 38.0%, whilst hatchability of set eggs in the thick-shelled group of old flock eggs was 58.3%.

Effect of rosemary (Rosmarinus officinalis) leaf meal supplementation on production performance and egg quality of laying hens.

This experiment was conducted to investigate the supplemental effect of rosemary leaf meal (RLM) on egg production and egg quality in Lohmann-Brown laying hens. For each treatment, six replicates were performed with four 24-week-old laying hens for a total of 96 chickens. Dried rosemary leaf meal (RLM) was present in the commercial laying hen ration at 0, 1.7, 3.5 and 5.2%, respectively. The interactions between dietary treatments, egg storage temperatures (4 °C, 21.5 °C), and egg storage durations (7, 14, 21, 28, and 35 days) were examined in factorial designs using a fully randomized design. The data were analyzed using the Statistical Analysis System (SAS, 2014, Ver. 9.3) and Tukey's multiple range tests to separate the means. The inclusion of dried RLM at a level of 5.2% (p < 0.05) significantly improved the hens' daily egg production (78.9%). Feed conversion ratio (2.25) and egg weight (56.7 g) compared to control treatment. Similarly, at 3.5% and 5.2% RLM supplementation, eggshell weight (5.876 g) and eggshell strength increased significantly (p < 0.05) (compared to control, a weight of 3.76 kg/cm2 and a shell thickness (0.37 mm) was observed. In addition, the groups fed 5.2% RLM had significantly higher albumin weight (34.9 g/L), albumin height (6.9 mm), and yolk weight (15.6 g/L). l), yolk height (15.9 mm), yolk color (5.3 points), and Hough unit (83.9 points) than the control groups. Regarding the external characteristics of stored eggs, a group of hens fed at rates of 3.5 and 5.2% RLM showed significantly greater (p < 0.05) egg weight with increases in storage temperature and duration as a control group. There was a significant interaction effect between stored eggs collected from the supplemented groups in terms of egg weight, weight loss, shell weight, shell strength, and shell thickness stored at specific temperatures and storage durations. There was a decrease in albumen level and Haugh unit (HU) with an increase in storage temperature and duration over treatment (P < 0.05). Therefore, better external quality was observed in eggs collected from a group of chickens fed 4.5 and 5.2% RLM after 35 days of storage compared to a control group. Mean albumen height, albumen weight, HU, yolk height, and yolk color of eggs stored in the refrigerator (4 °C) were an exception for yolk weight, which was higher compared to room temperature (21.5 °C). Significantly low (P < 0.05) albumen height (6.61 to 2.96 cm), Hough unit (82.49 to 47.64 points), and yolk height (14.66 to 12.35 mm) were observed at 35 days storage recorded in the control group. In conclusion, supplementation with RLM at 3.5% and 5.2% improved the performance and quality of both fresh and stored eggs.

Possible role of translation in unfertilized sea urchin eggs.

Unfertilized eggs of animals contain maternal messenger RNAs (mRNAs) and proteins, which are required for the maintenance of metabolism and regulation of development during the initial stages of embryogenesis. Unfertilized eggs are transcriptionally and translationally quiescent. After fertilization, activated translation of maternal mRNAs is one of the major forces that direct the early stages of embryogenesis before activation of the zygotic genome. However, a low rate and level of protein synthesis have been detected in unfertilized sea urchin eggs indicating that translation is not completely inhibited. Analysis of translatomes of unfertilized eggs and early embryos detected three sets of maternal mRNAs translated either before or after fertilization, or both before and after fertilization. Proteins encoded by maternal mRNAs, which are translated in unfertilized eggs, perform many different functions required for homeostasis, fertilization, egg activation, and early development. This suggests that translation in unfertilized sea urchin eggs may be required to renew the pool of proteins involved in these processes. Thus, translation may be necessary to maintain the fertility and developmental potential of sea urchin eggs during the long-term storage of eggs in ovaries until spawning begins.

Antimicrobial Coating Based on Tahiti Lemon Essential Oil and Green Banana Flour to Preserve the Internal Quality of Quail Eggs.

This study evaluated the microbiological and internal quality of quail eggs stored for 21 days at room temperature (29.53 ± 1.36 °C) after being coated with green banana flour and Tahiti lemon essential oil (GBF/TAH). One hundred and sixty-two quail eggs were equally distributed into three treatments: (1) uncoated eggs, (2) eggs coated with green banana flour (GBF), and (3) eggs coated with GBF/TAH. The Haugh unit (HU) of the eggs was significantly lower in the third week for uncoated eggs (70.94 ± 1.63, grade A) compared to eggs coated with GBF/TAH (81.47 ± 2.38, grade AA). On the 21st day of storage, the eggs coated with GBF/TAH had significantly lower total counts of aerobic mesophilic bacteria in the shell and egg contents compared to the other treatments. GBF/TAH coating is an effective blending approach to reduce the microbial load of the shell and egg contents and preserve the sensory and internal quality of the eggs.

The eggshell defect as a factor affecting the egg quality after storage.

The aim of the study was to assess the influence of shell defects on the quality of eggs after storage. The study material consisted of 1,800 brown-shelled eggs from cage rearing system which were candled on the day of laying to determine the shell quality. Eggs with the 6 most common shell defects (external crack, severe stripe marks, points, wrinkled, pimples, sandy) and eggs without defects (control group) were then stored for 35 days at 14°C and 70% humidity. The weight loss of eggs was monitored every 7 days, and the quality characteristics of whole eggs (weight, specific gravity, shape), shell (defects, strength, color, weight, thickness, density), albumen (weight, height, pH) and yolk (weight, color, pH) of 30 eggs from each group were analysed at the beginning (0 days) and after 28 and 35 days of storage. The changes resulting from water loss (air cell depth, weight loss, shell permeability) were also evaluated. The study showed that all investigated shell defects significantly influenced the characteristics of the whole egg during the storage, modifying traits such as specific gravity, water loss, shell permeability, albumen height and pH, as well as proportion, index and pH of the yolk. Furthermore, an interaction between time and the shell defects presence was found.

Synergy Between Dietary Quercetin and Vitamin E Supplementation in Aged Hen's Diet Improves Hatching Traits, Embryo Quality, and Antioxidant Capacity of Chicks Hatched From Eggs Subjected to Prolonged Storage.

The current study aims to investigate the effects of the synergy between quercetin and vitamin E in aged hen's diet on hatchability and antioxidant levels of the embryo and newly hatched chicks from prolonged storage eggs. A total of 400 breeder laying hens of 65 weeks of age were selected and randomly divided into 4 groups. Birds were fed a basal diet alone (Control), and basal diets supplemented with quercetin (Q) (0.4 g/kg) and vitamin E (VE) (0.2 g/kg) alone and their combination (0.4 g/kg Q + 0.2 g/kg VE) for 14 weeks, respectively, to determine their effects on yolk antioxidant status, fertility, embryonic mortality, hatchability, antioxidant status of embryonic tissues, as well as the antioxidant status of the newly hatched chicks. The results showed that the hen's dietary Q + VE increased the yolk weight, as well as increased the antioxidant status of the egg yolk (p < 0.05). Compared with the control group, the supplementation of Q + VE significantly increased the hatchability of set-fertile eggs and decreased early embryonic mortality in eggs stored for 7 and 14 days, respectively (p < 0.05), and also improved the antioxidant capacity of the embryos obtained from eggs stored for 14 days (before incubation) (p < 0.05). Moreover, Q + VE increased the levels of SOD, GSH-Px, T-AOC, T-SOD, and CAT in the liver, heart, and pectoral muscle of the embryo, 1-day-old and 14-day-old chicks (p < 0.05), as well as upregulated the antioxidant related genes (GPx-1, GPx-2, GPx-4, DIO-1, and SOD-1) in the liver of the embryo, 1-day-old and 14-day-old chicks hatched from 14-days storage eggs (p < 0.05). Meanwhile, the MDA levels were decreased by the Q + VE in the embryo and post-hatched chicks (p < 0.05). In conclusion, these findings suggested that maternal dietary Q + VE exerts beneficial synergistic effects on the antioxidant capacity of the egg yolk, embryo, and chicks during prolong egg storage, therefore, Q + VE could be used as a dietary measure to enhance hatchability and chick quality in poultry production.

Transcriptome analysis of blastoderms exposed to prolonged egg storage and short periods of incubation during egg storage.

BACKGROUND: Cool temperature egg storage prior to incubation is a common practice in the broiler industry; however, prolonged egg storage causes increased embryonic mortality and decreased hatchability and growth in surviving chicks. Exposing eggs to short periods of incubation during egg storage (SPIDES) reduces the adverse consequences of prolonged storage. SPIDES increases blastodermal cell viability by reducing apoptosis, though the counteracting mechanisms are unclear. To define the impact of prolonged storage and SPIDES, transcriptome analysis compared gene expression from blastoderms isolated from eggs exposed to the following treatments: control (CR, stored at 17 °C for 4 days), prolonged storage (NSR, stored at 17 °C for 21 days), SPIDES (SR, stored at 17 °C for 21 days with SPIDES), and incubated control (C2, stored at 17 °C for 4 days followed by incubation to HH (Hamburger-Hamilton) stage 2, used as the ideal standard development) (n = 3/group). Data analysis was performed using the CLC Genomics Workbench platform. Functional annotation was performed using DAVID and QIAGEN Ingenuity Pathway Analysis. RESULTS: In total, 4726 DEGs (differentially expressed genes) were identified across all experimental group comparisons (q < 0.05, FPKM> 20, |fold change| > 1.5). DEGs common across experimental comparisons were involved in cellular homeostasis and cytoskeletal protein binding. The NSR group exhibited activation of ubiquitination, apoptotic, and cell senescence processes. The SR group showed activation of cell viability, division, and metabolic processes. Through comparison analysis, cellular respiration, tRNA charging, cell cycle control, and HMBG1 signaling pathways were significantly impacted by treatment and potential regulatory roles for ribosomal protein L23a (RPL23A) and MYC proto-oncogene, BHLH transcription factor (MYC) were identified. CONCLUSIONS: Prolonged egg storage (NSR) resulted in enriched cell stress and death pathways; while SPIDES (SR) resulted in enriched basic cell and anti-apoptotic pathways. New insights into DNA repair mechanisms, RNA processing, shifts in metabolism, and chromatin dynamics in relation to egg storage treatment were obtained through this study. Although egg storage protocols have been examined through targeted gene expression approaches, this study provided a global view of the extensive molecular networks affected by prolonged storage and SPIDES and helped to identify potential upstream regulators for future experiments to optimize egg storage parameters.

Research Note: The nutritional value of eggs from native Polish Crested chickens and commercial hybrids that have been stored in various conditions.

The aim of the study was to compare the nutritive value of eggs from Polish Crested chickens (PCr) to that of eggs from commercial hybrid Hy-Line Brown (HLB) and to examine the effect of storage conditions on physical quality parameters. In total, 135 PCr (9 pens) and 75 (5 pens) HLB chickens were kept on litter and fed commercial feed. At laying peak (36 wk), all eggs (n = 66/ genotype) were collected on the same day and divided into 3 groups (n = 20): group I was assessed on the day after laying; group II was analyzed after 28 d of storage in a fridge; group III, after 28 d in storeroom conditions of 19.5 to 20.5°C. For group I, vitamin A and E content (n = 3 samples) and fatty acid (FA) profiles (n = 6 samples) were determined. For all groups, the physical quality parameters of the eggs were assessed. The vitamin E content was higher (P < 0.05) for PCr than HLB. The PUFA n-6 FA content was higher and the amount of MUFA was lower (P < 0.05) for PCr when compared to HLB. All physical parameters changed after storage, with more negative changes recorded for group III than for group II. Concerning egg weight, albumen height, Haugh unit score and the pH of the yolk and albumen, interaction between genotype and storage conditions (P < 0.001 - P < 0.05) was demonstrated. The lightest eggs with the lowest albumen height and the highest pH were recorded from PCr in group III. The lowest Haugh unit score was recorded from HLB eggs stored in the same conditions. Moreover, the eggs of PCr were characterized by a higher (P < 0.001) yolk content and yolk color (P < 0.05), whereas the weight of the yolk and content of albumen were lower (P < 0.001) for HLB. Eggs from PCr that are stored in appropriate conditions could possibly be offered as a niche product.

Storage temperature dictates the ability of chicken embryos to successfully resume development by regulating expression of blastulation and gastrulation genes.

The avian embryo has a remarkable ability that allows it to suspend its development during blastulation for a long time at low temperatures, and to resume normal development when incubated. This ability is used by poultry hatcheries to store eggs prior to incubation. We have previously found that this ability correlates with the temperature during storage; embryos recover much better following prolonged storage at 12°C rather than at 18°C. However, the molecular and cellular mechanisms underlying these differences are poorly understood. To successfully resume development following storage, the embryo has to shift from the blastulation phase to gastrulation. Several genes are known to partake in the blastulation-to-gastrulation transition under normal conditions, such as the pluripotency-related genes Inhibitor of DNA Binding 2 (ID2) and NANOG that are expressed during blastulation, and the gastrulation-regulating genes NODAL and Brachyury (TBXT). However, their expression and activity following storage is unknown. To elucidate the molecular mechanisms that initiate the ability to successfully transit from blastulation to gastrulation following storage, embryos were stored for 28 days at 12°C or 18°C, and were assessed either prior to incubation, 12, or 18 h of incubation at 37.8°C. Immediately following storage at 18°C group showed remarkable impaired morphology compared to the blastoderm of the 12°C group and of non-stored control embryos. Concurrently with these, expression of ID2 and NANOG was maintained following storage at 12°C similar to the control group, but was significantly reduced upon storage at 18°C. Nevertheless, when the 18°C-stored embryos were incubated, the morphology and the reduced genes were reverted to resemble those of the 12°C group. At variance, key gastrulation genes, NODAL and its downstream effector Brachyury (TBXT), which were similarly expressed in the control and the 12°C group, were not restored in the 18°C embryos following incubation. Notably, ectopic administration of Activin rescued NODAL and TBXT expression in the 18°C group, indicating that these embryos maintain the potential to initiate. Collectively, this study suggests a temperature-dependent mechanisms that direct the transition from blastulation to gastrulation. These mechanisms promote a successful developmental resumption following prolonged storage at low temperatures.

The Use of the Dynamics of Changes in Table Eggs during Storage to Predict the Age of Eggs Based on Selected Quality Traits.

The aim of the study was to determine daily changes in some egg quality parameters, indirectly reflecting egg freshness, and to assess the possibility of predicting time from laying using mathematical methods. The study material consisted of 365 table eggs of medium (M, ≥53 g and <63 g) and large (L, ≥63 g and <73 g) weight classes (commercial stock, cage system, brown-shelled eggs) collected on the same day. Eggs were numbered individually and placed on transport trays and stored (14 °C, 70% RH). Every day, for 35 days, egg quality characteristics were analyzed (10 eggs per group). The change of traits in time was analyzed on the basis of linear and polynomial regression equations, depending on the trait. Based on model fitting, eight traits were selected as those most affected by storage time: egg weight and specific weight, Haugh units, albumen weight, air cell depth, yolk index, albumen and yolk pH. These traits, excluding those related to the weight, were then used in a multiple linear regression model to predict egg age. All regression models presented in this study were characterized by high predictive efficiency, which was confirmed by comparison of the observed and estimated values.

Effects of egg storage duration on egg quality, metabolic rate, hematological parameters during embryonic and post-hatch development of guinea fowl broilers.

Considering the value of guinea fowl keets, successful incubation of eggs is particularly desirable in this poultry species. This study evaluated the effect of egg storage duration on egg quality, heat production, hematological parameters during embryonic development and post hatch performance of guinea fowl broilers. A total of 800 hatching eggs of guinea fowl were used for this study. Before incubation, 12 eggs per treatment were used to analyse egg quality. Then, eggs were numbered, weighed, and assigned to 2 treatment groups of 400 eggs each according to storage duration of 5, and 10 d at a temperature of 18°C. The eggs were set for incubation at 37.7°C and 55% relative humidity for 28 d in a forced-draft incubator. To determine heat production as a measure of metabolism, 60 eggs in each replicate were transferred to respiratory cages post hatch two 12 wk old guinea fowl were also used to determine heat production. CO2 and O2 were recorded to calculate heat production at internal pipping, hatch and at 12 wk of age. The hatched keets were reared for 12 wk and data were collected on feed intake, body weight and feed conversion ratio. Blood samples were collected at hatch and at 12 wk of age from 24 guinea fowls per treatment to analyze haematological parameters. The results showed that embryos and guinea fowls at 12 wks of age from eggs stored for 5 d had higher (P ˂ 0.05) heat production and body weights. However, a significant higher (P ˂ 0.05) level of basophile, eosinophils, and lymphocytes was observed in guinea fowls from 10 d storage egg. It was concluded that extended duration of egg storage negatively influenced the metabolic rate of embryos. It also impacted hematological parameters which may suggest influence on immune response during embryonic and post-hatch growth.

The Impact of Package Type and Temperature on the Changes in Quality and Fatty Acids Profile of Table Eggs during Their Storage.

The aim of the study was to evaluate the possibility of reducing changes in the quality of consumer hen eggs by storing them in various package type and under various temperature conditions (room and refrigeration). The material consisted of 960 chicken eggs packed in cardboard or plastic boxes, 10 pcs in each. Half of the packages were stored at room temperature (21 °C), the rest in the refrigerator (5 °C). The eggs were stored for 28 days qualitatively evaluated at 14-day intervals. The characteristics of whole egg (weight, specific weight, proportion of morphological elements, air cell depth) as well as of shell (weight, color, crushing strength, thickness, density, water conductivity), albumen (height, Haugh units, weight, pH) and yolk (weight, color, pH) were analyzed. The fatty acids profile of yolks was also evaluated as a freshness indicator. Packaging types available on the market, apart from its marketing and eggs protection function, can also influence the quality and stability of the product during storage. The use of plastic boxes can help to maintain higher eggs quality during the storage period, even after a significant extension of the storage time. Eggs stored in plastic boxes at room temperature had very similar results to those stored under refrigeration using conventional cardboard boxes. This effect is probably related to the lower permeability of plastic boxes in comparison to cardboard ones, but detailed research work in this direction is necessary to verify this relation.

Research Note: Effects of preincubation and higher initiating incubation temperature of long-term stored hatching eggs on hatchability and day-old chick and yolk sac weight.

We studied the effect of increased initial incubation temperature and repeated preincubation of 35-d stored eggs from 46-week-old Ross 308 parental stock on the hatchability and day-old chick and yolk sac weight. Two different temperatures were applied during the first 36 h and they were combined with 4 preincubation treatments during storage. One half of the hatching eggs (2,400) were incubated for the first 36 h at an incubation temperature of 38.3°C, and the second half were incubated at a higher temperature of 39.2°C. Four different preincubations were applied; none, once at the 7th d of hatching egg storage, twice at the 7th and 12th d of storage and 3 times at the 7th, 12th and 19th d of storage. Both preincubation and increased temperature had negative effects on hatchability (P < 0.001). The interaction between these 2 factors was also significant (P < 0.05). These 2 factors also negatively affected early and late embryonic mortality (P < 0.001). However, middle embryonic mortality was not influenced. Live weight, weight of residual yolk sac, and yolk sac proportion were not affected by repeated preincubation nor by increased temperature over the first 36 h of incubation (P > 0.05). A higher initial temperature decreased chick yolk free body mass (P < 0.05). Although neither increased initial temperature in the setter nor repeated preincubation affected one-day-old chick weights, these treatments were not suitable for long-term stored eggs because of decreased hatchability and impairment of one day chick yolk free body mass.

The chick blastoderm during diapause, a landmark for optimization of preincubation storage conditions.

At the time of oviposition, the chicken embryo is in its blastodermal stage. The blastoderm displays the unique ability to undergo developmental arrest at low temperatures in a process called "embryonic diapause." In the wild, diapause occurs in freshly laid eggs until the last egg of the clutch has been laid, providing an evolutionary advantage to hens that can synchronously hatch their eggs. The poultry industry utilizes the diapause phenomenon to store eggs before incubation, thereby mitigating their logistic problems. The embryos can only be stored at particular embryonic stages-termed "diapause developmental window" (DW)-if they are to continue to develop normally thereafter. Both cellular and molecular mechanisms define the limits of this DW which broadly comply with onset of blastulation to early gastrulation. Storage conditions affect the cellular and molecular characteristics of the embryo during this window and their ability to successfully resume development (SRD). At storage temperatures of ~12°C to 18°C, embryos can undergo diapause for a short period (up to 7 days (d)) without affecting SRD. However, following longer period of diapause (up to 28 d), embryo stored at ~12°C, but not at ~18°C, can resume development normally. Moreover, eggs can be heated before or during the storage period which will lead to their commencing in development; however, unlike the non-heated embryos, the storage temperature for heated embryos, which are more advance in developing, is not clear. Thus, based on SRD, this review brings evidence supporting the notion that a lower storage temperature is beneficial for early-stage blastoderms whereas a higher storage temperature is favorable for later-stage/gastrulating embryos. Our understanding of the molecular mechanisms underlying the relationship between storage temperature and development stage within the DW is rather limited. However, it is expected to become relevant in light of the effect of selective breeding of modern avian birds on the advancement of embryonic development stage. Thus, this review discusses parameters that are regulated during the DW and affect SRD, and presents the need to adopt new storage techniques. The pre-managerial decision of required duration of storage with manipulation of storage temperature in the currently used storage techniques may improve SRD characteristics.

The impacts of egg storage time and maternal dietary vitamin E on the growth performance and antioxidant capacity of progeny chicks.

Two trials were designed to investigate the impacts of egg storage time and maternal dietary vitamin E (VE) supplementation on the growth performance and antioxidant capacity of progeny chicks. In total 512 Ross 308 broiler breeder hens (71-wk-old) were assigned to 2 dietary VE treatments (6 and 100 mg/kg) for 14 wk. Progeny chicks used in trials 1 and 2 were originated from eggs laid at week 10 (stored 0 d) and week 8 (stored 14 d), and week 14 (stored 0 d) and week 12 (stored 14 d), respectively. The 4 groups in trial 1 consisted of 2 levels of maternal VE (6 and 100 mg/kg) and 2 egg storage time (0 and 14 d). The 8 groups in trial 2 consisted of 2 levels of maternal VE (6 and 100 mg/kg), 2 egg storage time (0 and 14 d) and progeny sex (male and female). In trial 1, egg storage decreased the body weight, the liver total superoxide dismutase and total antioxidant capacity of 21-day-old offspring (P < 0.05), and the body weight gain and feed intake from 8 to 21 d and 1 to 21 d (P < 0.05); and increased the serum and liver malonaldehyde (MDA) of 7-day-old offspring and the ratio of feed: gain (F/G) from 1 to 7 d (P < 0.05). Maternal VE (100 vs. 6 mg/kg) decreased the F/G from 1 to 7 d and increased the serum total superoxide dismutase of 21-day-old offspring (P < 0.05). In trial 2, egg storage decreased the body weight of 42-day-old offspring, and the body weight gain and feed intake from 22 to 42 d and 1 to 42 d (P < 0.05); and increased the serum and liver MDA of 21- and 42-day-old offspring (P < 0.05). Maternal VE (100 vs. 6 mg/kg) reduced the serum MDA of 7-day-old offspring (P < 0.05). Interactively, maternal VE (100 vs. 6 mg/kg) reduced the serum MDA of offspring originated from stored eggs (P < 0.05), but not for that of offspring originated from unstored eggs in the two trials. It can be concluded that egg storage (14 vs. 0 d) decreased the growth performance and antioxidant capacity of offspring, while maternal dietary VE (100 vs. 6 mg/kg) supplementation could partly alleviate the reduction of antioxidant capacity (except for growth performance) of offspring induced by egg storage for the early phase post-hatch.

Oocyte Ageing in Zebrafish Danio rerio (Hamilton, 1822) and Its Consequence on the Viability and Ploidy Anomalies in the Progeny.

Fish egg quality can be markedly influenced by the oocyte age after ovulation. In this study, we examined the duration of oocyte ageing in the zebrafish (Danio rerio) and whether prolonged ageing is associated with the incidence of ploidy anomalies in the resulting embryos. Oocytes were incubated in vitro for 6 h post-stripping (HPS) at 26 °C and fertilized at 2-h intervals. Meanwhile, for eggs fertilized immediately after stripping, the fertilization, embryo survival, and hatching rates started at ~80%; these rates decreased to 39%, 24%, and 16%, respectively, for oocytes that had been stored for 4 h (p ˂ 0.05), and there was an almost complete loss of egg viability at 6 HPS. Furthermore, almost 90% of the embryos derived from 6-h aged oocytes died prior to hatching, and all larvae originating from 4- and 6-h aged oocytes showed malformations. The proportion of ploidy abnormal embryos was significantly greater at 4 HPS (18.5%) than at either 0 or 2 HPS (4.7% and 8.8%, respectively). The results revealed that zebrafish oocytes retained their fertilization potential for up to 2 h after stripping at 26 °C and indicated the contribution of post-ovulatory oocyte ageing in the occurrence of ploidy anomalies in the resulting embryos.

Effects of Maternal and Progeny Dietary Vitamin E on Growth Performance and Antioxidant Status of Progeny Chicks before and after Egg Storage.

Two trials were conducted to investigate the effects of maternal and progeny dietary vitamin E (VE) supplementation on the growth performance and antioxidant status of offspring before and after egg storage. A total of 576 75-week-old Ross 308 breeder hens were assigned to three dietary VE treatments (100, 200, and 400 mg/kg) with 6 replicates of 32 hens for 12 weeks. Two trials were conducted with offspring hatched from eggs laid at weeks 9 and 12 of breeder feeding trial, respectively. Trial 1 was conducted by a 3 × 2 factorial arrangement of treatments with three levels of maternal dietary VE (100, 200, and 400 mg/kg) and two levels of progeny dietary VE (0 and 35 mg/kg). Trial 2 was conducted with three maternal dietary VE treatment (100, 200, and 400 mg/kg), and chicks were hatched from eggs stored for 14 d and received the same progeny diet with no addition of VE. Results showed that in trial 1, maternal (100, 200, and 400 mg/kg) and progeny (0 and 35 mg/kg) dietary VE supplementation did not affect the growth performance of offspring hatched from unstored eggs (p > 0.05). In trial 2, in the case of long-term egg storage, maternal dietary VE supplementation of 200 and 400 mg/kg increased the body weight (BW) of 21- and 42-d-old offspring and the body weight gain (BWG) of offspring from 1 to 21 d (p < 0.05), and decreased the feed conversion ratio (FCR) of offspring from 1 to 21 d (p < 0.05) compared to 100 mg/kg VE. As the maternal dietary VE levels increased, the liver and serum antioxidant status of offspring enhanced (p < 0.05). In conclusion, maternal dietary VE supplementation of 200 or 400 mg/kg could improve the growth performance and anti-oxidant status of offspring hatched from stored eggs, but not for that of offspring hatched from unstored eggs. The suitable VE level for the broiler breeder diet was 400 mg/kg in the case of long-term egg storage.