Changes In Egg Quality Research Articles

Dynamic Changes in Egg Quality, Heritability and Correlation of These Traits and Yolk Nutrient throughout the Entire Laying Cycle.

Egg quality and nutritional value are becoming increasingly important to consumers, offering a new direction for the development of high-quality eggs. In this study, we conducted a comprehensive analysis of egg quality and nutrient profiles in native breeds at different ages, integrating pedigree data. Our results reveal dynamic changes in egg qualities, stronger associations among eggshell-related traits, and the effect of onset production and body weight on egg qualities. The heritability of different traits was estimated, ranging from 0.05 to 0.62. Subsequently, we elucidated that the moisture and nutritional content in the egg yolk were not influenced by the percentage of yolk but were indeed subject to age regulation. There was a notable decrease in moisture, an elevation in crude fat, and an increase in the diversity of fatty acids of yolk with advancing age. In summary, investigating the trends and interrelationships in egg quality, nutrient content, and heritability across the whole laying cycle offers valuable insights for breeders to optimize feeding management strategies and aids consumers in meeting their expectations of egg quality.

Statistical and fuzzy modeling for accurate prediction of feed intake and surface temperature of laying hens subjected to light challenges

The use of artificial lighting for laying hens in poultry houses allows production optimization. However, the effect of recent lighting technologies needs to be investigated, as their use can affect the welfare of hens, causing biological rhythm, behavior, health, productive and reproductive performance and egg quality changes. Therefore, the objective of this study was to evaluate the physiological responses, productive performance and egg quality of hens under different light intensities. If a significant difference between treatments was found, statistical models and fuzzy inference systems (FISs) to predict such responses were developed and compared. Thus, 76 Hy-Line W-80 laying hens were housed in a controlled environment with temperature, relative humidity and air speed adjusted for bird comfort. The hens were exposed to illuminances of 5, 20, 50 and 100 lx for a period of 21 days. Among the evaluated response variables, only the mean feed intake (FI) and surface temperature (tsurf) of the hens had a significant interaction and interaction sliced by main factors (p < 0.05), allowing statistical model adjustment. For these two variables, FISs were also developed so that the illuminance and the time of exposure to illumination (tillu) were defined as input variables of the systems. As a result, the statistical models and FISs presented significant high-accuracy indexes when predicting the FI and the tsurf (except for R2 values related to the statistical models), yet with an advantage for the FISs models, in which greater generalization capabilities were obtained in the validation step. Therefore, the developed models can be used to support decisions related to the management of hens, supporting the smart production, with emphasis on FISs based on expert knowledge, since they can be used to obtain predicted responses in different scenarios in addition to those evaluated experimentally with high accuracy.

Combination of sensory evaluation with conventional physiochemical analyses to evaluate quality changes during long-term storage and estimate the shelf life of chicken eggs

ABSTRACT 1. This study developed a comprehensive sensory evaluation system that consisted of descriptions corresponding to United States Department of Agriculture photos to evaluate overall acceptability, albumen and yolk appearances and odours. It determined physiochemical parameters of eggs stored at 7°C (7W12 and 7U12 for washed and unwashed, respectively) for 12 weeks and stored at 25°C (25W4 and 25U4 for washed and unwashed, respectively) for four weeks. 2. Throughout storage, there was a general downward trend in Haugh units (HU) and yolk index and an upward trend in air cell size, weight loss and S-ovalbumin content were observed (P < 0.05). The 25W4 and 25U4 egg quality rapidly deteriorated from grade AA (HU 81.7) to grade B after two weeks (HU 46.5 and 49.6), whereas 7W12 and 7U12 eggs remained grade A after 12 weeks (HU 67.3 and 66.9). High correlations were observed between the sensory and physiochemical parameters (i.e., R2 = 0.93, 0.93, 0.88 and 0.94 for albumen appearance, yolk appearance, sensorial odour and overall acceptability, respectively, with HU in 25W4 eggs). 3. Eggs stored at 25°C and classified into ‘premium’, ‘class I’, and ‘class II’ on the basis of their HU had estimated shelf life of 0.5, 1.5 and 2.5 weeks, while shelf lives of 4, 9 and 15 weeks were estimated for 7°C-stored premium, class I and II eggs, respectively. 4. In conclusion, distinct HU requirements for eggs of different quality classes under two storage temperatures need to be established. Incorporating sensory evaluation with conventional physiochemical analyses is promising to assess and estimate egg quality changes. Further research work about the influences of different storage temperatures and possible temperature fluctuations during storage on egg quality changes is needed.

Feeding dihydroquercetin in wheat-based diets to laying hens: impact on egg production and quality of fresh and stored eggs

ABSTRACT 1. This study assessed the impact of dietary dihydroquercetin (DHQ) in wheat-based diets on egg production, composition and quality when fed to laying hens. A total of 80 Hy-Line Brown hens were allocated to 20 enriched layer cages, over two tiers, in groups of four birds. 2. Two wheat-based diets were used in the study. A basal diet, meeting the nutrient requirement of the hens, containing 11.56 MJ/kg AME and 172 g/kg crude protein, was mixed and split into two parts. One part was fed as prepared to the control group of birds. The second diet was made by adding 1.5 g DHQ per kg basal diet and fed to the treatment group of birds. This level was relatively high and extended the data on levels normally fed. The diets were fed in a meal form and did not contain any coccidiostat, antimicrobial growth promoters or other similar additives. Each diet was fed to hens in 10 replicate cages for 4 weeks, from 22 to 26 weeks of age, following randomisation. 3. Subsequently, eggs were investigated to determine the impact of dietary DHQ on the quality variables of fresh and 28-d stored eggs. 4. Overall, feeding 1.5 g/kg dietary DHQ for 4 weeks did not affect (P > 0.05) egg production or the quality of fresh and stored eggs. Any observed egg quality changes (P < 0.05) confirmed the expected effects of egg storage.

Effect of a Hypoxia-Controlled Atmosphere Box on Egg Respiration Intensity and Quality

Egg preservation is an important factor during storage and transportation. Fresh eggs were stored in boxes in a controlled atmosphere with an O2 concentration of 0% O2 + 100% nitrogen (N2), 5% O2 + 95% N2, 10% O2 + 90% N2, 15% O2 + 85% N2, and 20% O2 + 80% N2, and the effects of these storage conditions on large quantities of eggs were studied. The respiratory intensity and quality of eggs during storage were measured. We chose the weight loss rate of eggs, Haugh unit, pH, and the egg white total plate count as the characteristic indices of egg quality. We compared the changes in egg quality during and after storage at different O2 concentrations versus that at 25 °C. The stages were evaluated using the TOPSIS method to sort egg quality, and the optimal O2 concentration was selected. FLUENT was used to simulate and control the atmospheric requirements. Our findings showed that eggs stored in an air-conditioning chamber with O2 concentration ≤10% exhibited weak respiratory intensity (0–1 mg/(kg·h)). The rates of decrease in loss of egg weight and Haugh units were smaller. There were significant differences in the pH of egg white stored in different O2 concentrations (p &lt; 0.05). Reducing the O2 concentration in the egg-storage environment reduced the number of colonies in eggs and had a positive effect on egg preservation. Simulations using FLUENT revealed that only 1200 s were required to achieve the low-oxygen environment in the controlled atmosphere box (1.5 m × 1 m × 1 m). The storage environment of 5% O2 + 95% N2 had the best preservation effect on eggs. This approach is associated with low costs in practical application and can potentially be used for egg storage and transport.

Effect of Cladosporium cladosporioides on the Composition of Mycoflora and the Quality Parameters of Table Eggs during Storage

The eggshells of 120 experimental one-day-old table eggs were contaminated with the spore suspension of Cladosporium cladosporioides, divided into three groups (A–C) and stored at three different temperatures (3 °C, 11 °C and 20 °C) for 28 days. Visible growth of molds on/in experimental eggs was not observed within the entire storage period. No significant differences in the numbers of molds were found between particular groups of eggs. However, the composition of egg mycoflora was greatly influenced by storage conditions. Three mold genera were identified using the PCR method. The highest mold numbers were determined on Day 14 (Groups A and C) and Day 21 (Group B) when the maximum relative humidity and dew point temperature were recorded. On the same days, the dominance of Penicillium spp. and the minimum eggshell firmness were observed. Noticeable changes in egg quality were observed in eggs stored at 20 °C, and most of these eggs were downgraded at the end of storage period. The growth ability differed significantly among three mold genera. Penicillium spp. and Fusarium spp. showed better growth intensity at increased values (0.91–0.94) of water activity (aw) indicating a possible risk associated with the occurrence of mycotoxins in the egg contents.

Physicochemical parameters and morphological qualities of edible eggs depending on the period of the reproductive period of chickens

Changes in egg quality observed under intensive poultry farming conditions indicate the possibility of regulating these parameters without violating their inherent high nutritional benefits. Morphological characteristics, such as the weight and shape of the egg, the weight of the yolk, protein, shell, its strength and others are determined mainly by genetic factors and conditions of keeping and feeding. Egg mass is the most important physical indicator of nutritional and market value, which determines the productivity of poultry. At 26 weeks of age (beginning of laying) the egg weight averaged 57.7 ± 0.81 g, and at 80 weeks of age (end of laying) - 62.2 ± 1.86 g. The weight of eggs obtained from hens of the cross “Lohmann-white”, increased due to changes in the absolute mass of its constituent components. The mass of egg white during the reproductive period increased by 4.50–4.99%; yolk - by 6.8-14.9%; shells - by 4.4-18.8%, although this practically did not affect their ratio in percentage terms. The shell thickness increased from 365.0 ± 6.99 microns to 378.0 ± 7.09 microns. With an increase in the shell thickness, the density of eggs also increased from 1.070 ± 0.002 g / cm3 to 1.078 ± 0.002 g / cm3. The shape index of eggs ranged from 71.5 - 74.9%, while the increase in egg mass was accompanied by a decrease in the shape index. During the reproductive period, the Howe index was at the level of 82.5-84.4 conventional units. The protein index and Howe units decreased with age. All morphological and physicochemical parameters corresponded to the optimal values: protein index from 7.6 to 8.4%, yolk index from 39.0 to 42.0%, shape index from 74.9 to 75.3, Hau units from 82, 5 to 84.4 conventional units.

Albumen Quality of Fresh and Stored Table Eggs: Hen Genotype as a Further Chance for Consumer Choice.

Simple SummaryConsumer interest in food products and their origins is increasing. Knowledge of egg production and quality of purebred hens during the productive period is required for a niche market sustaining and encouraging biodiversity and the peculiarities of the products that consumers can appreciate. Egg production and quality of the eggshell and albumen in fresh and stored eggs of two Italian dual-purpose purebreds (Ermellinata di Rovigo (ER); Robusta maculata (RM)) and two hybrid genotypes (Hy-Line Brown (HB); Hy-Line White (HW)) reared outdoors were compared throughout the laying period. RM breed (brown eggshell) showed fresh and stored eggs with a good eggshell thickness, and Haugh Units (HU) quite stable along the production period; RM total egg mass was lower than ER (light brown eggshell) which showed fresh and stored eggs with more variable HU, due also to a possible effect of lower eggshell thickness and pigmentation, and shape index. The hybrids produced a higher total egg mass than the purebreds and showed an intermediate variation of the egg quality, with HU higher than those of ER and RM only in 1 d eggs, but not in stored eggs.The quality of fresh (1 d) and stored (7–14–21 d, 21 °C) eggs was studied in Italian dual-purpose breeds (Ermellinata di Rovigo (ER), Robusta maculata (RM)) and hybrids (Hy-Line Brown (HB), Hy-Line White36 (HW)), reared outdoors (4 m2/bird) and fed commercial feed. The eggs were analyzed at 4 ages, throughout different seasonal environmental conditions, from summer (31, 35 weeks; 25 °C) until autumn (39, 43 weeks, 15 °C). Each genotype showed significant (p < 0.01) changes in egg quality. In 1 d eggs, the eggshell thickness changed in RM and HW (quadratic), decreased linearly in ER; Haugh Units (HU) changed (ER–cubic) and decreased (hybrids-linear). In 7 d and 14 d eggs, HU linearly (p < 0.01) decreased, except in RM. In 21 d eggs, HU (ER linear decrease; HB, HW quadratic) changed. Significant negative correlations between albumen pH and height were seen in ER (at 1 d, 14 d, 21 d) and HW (at each storage time) eggs, and in RM and HB only in 1 d eggs. RM showed a quite stable albumen quality and a lower total egg mass than ER which showed a more variable albumen quality, due also to a lower eggshell thickness and shape index. The hybrids produced a higher total egg mass than the purebreds and showed an intermediate variation of the egg quality, with an albumen quality higher than those of ER and RM only in 1 d egg, as a result of a higher albumen weight.

Biofortification of Chicken Eggs with Vitamin K-Nutritional and Quality Improvements.

National nutrition surveys have shown that over half of all adults in Ireland, the United Kingdom (UK), and the United States of America (USA) have low vitamin K intakes. Thus, dietary strategies to improve vitamin K intakes are needed, and vitamin K biofortification of food may be one food-based approach. The primary aim of our study was to establish whether increasing the vitamin K3 content of hen feed can increase the vitamin K content of eggs, and the secondary aims were to examine the effects on hen performance parameters, as well as egg and eggshell quality parameters. A 12 week hen feeding trial was conducted in which Hyline chickens were randomized into four treatment groups (n = 32/group) and fed diets containing vitamin K3 (as menadione nicotinamide bisulfite) at 3 (control), 12.9, 23.7, and 45.7 mg/kg feed. Vitamin K1, menaquinone (MK)-4, MK-7, and MK-9 were measured in raw whole eggs via a liquid chromatography tandem mass spectrometry method. MK-4 was the most abundant form of vitamin K (91–98%) found in all eggs. Increasing the vitamin K3 content of hen feed over the control level significantly (p < 0.001) enhanced the MK-4 content of eggs (mean range: 46–51 µg/100 g, representing ~42–56% of US Adequate Intake values). Vitamin K biofortification also led to significant (p < 0.05) increases in the yellowness of egg yolk and in eggshell weight and thickness, but no other changes in egg quality or hen performance parameters. In conclusion, high-quality vitamin K-biofortified eggs can be produced with at least double the total vitamin K content compared to that in commercially available eggs.

Triple La Sota re-vaccinations can protect laying chickens for 3 months against drop in egg production caused by velogenic viscerotropic Newcastle disease virus infection.

One hundred and ten Isa Brown layers were vaccinated with La Sota, once at point of lay at 18 weeks and three times at peak of lay which occurred at 27–29 weeks of age. Thereafter, they were weekly monitored for haemagglutination inhibition (HI) antibody decline. The first batch A of the layers were challenged with velogenic viscerotropic Newcastle disease (vvND) virus (vvNDV) on day 24 post‐vaccination (PV), when the geometric mean titre (GMT) was 84.4, batch B were challenged on day 48 PV at GMT of 42.2, while batch C were challenged on day 97 PV at GMT of 21.1. The individual chicken HI antibody titres of the 10 layers in batch C at the day of challenge were: 7 layers had HI titres of 16, 2 layers had HI titres of 32 and 1 layer had HI titres of 64. Each challenge in the three batches produced no clinical signs including drop in egg production. But there was initial swelling of the spleen followed by atrophy with high antibody responses. The virus was recovered in all the cloacal swabs on days 3–9 post‐challenge (PC) at low titres. On days 145 PV and 48, post‐Batch C challenge the remaining hyperimmunized unchallenged layers demonstrated a drop in total % egg production (p < .05) and changes in egg quality. The HI GMT was 256. The virus was recovered in all the cloacal swabs on days 3–9 following appearance of clinical signs. There was no mortality in the experiment. Based on the above observations, it is concluded that triple La Sota re‐vaccination can protect layers against a drop in egg production in areas where vvNDV infection is enzootic.

Effect of Hens Age and Storage Time on Functional and Physiochemical Properties of Eggs

SUMMARY In this study, we aimed to determine the effect of hens age and storage time on the functional and physicochemical properties of eggs. Eggs from hens 25–26, 45–46, 55–56, and 69–70 wk of age were assessed, when fresh (0 d) and after storage 3, 6, and 9 d at 30°C and at 50% humidity. As hens age and storage time progressed, albumen height, Haugh unit (HU) score, yolk index (YI), and vitelline membrane strength (force breaking and elasticity) significantly decreased. The values of albumen height, HU, and YI were found to be higher in eggs obtained from the younger hens (25–26 wk of age) than those from the older hens. A significant effect of hens age was also found on the yolk pH and water activity. There was no statistical difference observed between the analyzed parameters of eggs from older hens (45–70 wk of age). There was no effect of hens age on the egg quality that was found to be the best when fresh. Interaction between hens age and the storage time also had significant impact on egg weight, albumen height, HU, yolk pH and YI, yolk weight, yolk ratio, and water activity. HU and YI scores were found to be greatly influenced by the age of hens and storage time of eggs. Changes of egg quality from the younger and older hens during storage have proceeded similarly, but eggs from older hens had significantly higher eggs weight and yolk weight that changed slowly.

Efficacy of Sweet Potato Starch-Based Coating to Improve Quality and Safety of Hen Eggs during Storage

Egg deterioration occurs during storage time, which leads to quality loss. Thus, different preservations methods have been used to extend the shelf-life and maintain the safety of eggs. Edible coating materials based on biopolymers, such as starches and other renewable sources, have been used for different food products and been identified as an effective method of food preservation. In this study, eggs were coated with edible coatings prepared from sweet potato starch (SPS) and varying levels of thyme essential oil (TEO), including 0 (control), 2%, 4%, and 6%. The quality and safety of the coated and uncoated eggs during five weeks of storage at 25 °C were studied. The application of 4% TEO in SPS-based coatings maintained the quality and safety of eggs two weeks longer than non-coated eggs. This study showed that the SPS-TEO coating could be useful in extending the shelf life of eggs during storage time, by delaying changes in egg quality.

Effect of non-conventional storage methods on external and internal egg qualities

To know and identify the traditional practices and generate relevant information on egg storage methods, a survey work was conducted in the East Wollega Zone of Ethiopia. The survey was carried out with a stratified sampling technique and a structured questionnaire using a total of 315 households (225 from rural and 90 from urban owning chickens) were purposefully selected. Two experiments, of similar experimental materials, procedures and designs were conducted at different time of the year (May and August) to evaluate these traditional storage methods at Haramaya University poultry farm. A factorial experiment of 2 by 5 with completely randomized design using storage containers and storage time as treatment was used. The storage times were 4, 6, 8, 12 and 20 days. Five most common egg storage containers were identified in the rural and urban areas of East Wollega. These storage methods include cartons, polyethen bags, baskets, clay pots and teff grain. The result further indicated that depending on the availability of the storage materials in the locality, 87 percent of the urban households (n = 90) store eggs in cartons and polyethene bags in order of availability. Seventy nine percent of the rural households (n = 225) ranked teff as the most common storage materials used followed by the basket and clay pots. Among the quality parameters considered, weight loss (%) and daily weight loss (%) of eggs were highly affected (P < 0.001) by storage containers, durations and their interactions during both experiments. The maximum weight loss was observed after storage period of 16 days for all containers. Polythene bags storage maintained minimum weight loss Vs the baskets at all stages of storage duration. Only storage durations had significant effects (P < 0.05) on the egg shell thickness during experiment I. Inconsistent but significant effect of storage durations was observed on the shell weight during experiment I, and weights of yolk and albumen during experiment II. Storage containers during experiment I, and storage durations during experiment II showed significant effects on albumen height and haugh unit values. Except polythene bags which had higher albumen height and haugh unit values, the other containers did not show significant variations for both parameters. The effect of storage duration on these parameters was linear with increasing storage duration; and higher beyond the 16 days of storage. Thus, it was concluded that using polyethylene bags and 16 days of storage could give the best result to store eggs among the traditional methods compared in this experiment. Keywords: Traditional Egg Storage; Changes in Egg Quality; Optimum Egg Storage Duration

Effect of dietary canthaxanthin and iodine on the production performance and egg quality of laying hens.

In this study, we aimed to evaluate the effect of canthaxanthin (CX) and iodine (I) on the production of laying hens, on counteracting debilitation of the vitelline membrane, and on inhibiting Salmonella growth in eggs stored at 30°C. Three hundred hens were reared in cages. Birds were divided into six feeding groups (10 hens × 5 repetitions) that were administered 0, 3 or 6ppm of CX and 1 or 10ppm of I with their diets. Laying rate, egg weights, and feed conversion ratios were controlled. The quality of fresh eggs was assessed in wks 25-26, 48-50 and 62-63 of hens lives. An additional batch of eggs was incubated at the temperature of 30°C, and egg quality changes were monitored on days 3, 6 and 9 of storage. Additionally, eggs collected from four experimental groups of hens whose diets had been iodated with 1 or 10ppm of I and supplemented with 0 or 6ppm of CX were infected under laboratory conditions with Salmonella, and incubated for 5 and 10 d. The laying rate, egg weights, and feed conversion ratio were significantly improved. Dietary inclusion of CX contributed to a higher resistance of the vitelline membrane of egg yolks, but only for fresh eggs. Vitelline membrane degradation during egg storage at 30°C was significantly counteracted by dietary inclusion of I at a dose of 10ppm. The same I dose resulted in the complete inhibition of Salmonella growth until day 10 of incubation, but exclusively for eggs collected from 40-week-old hens. Dietary supplementation with 10ppm of I was found to impart high level of resistance to the vitelline membrane against the growth of Salmonella in case of eggs stored at 30°C; therefore, I was found to be more beneficial by ensuring longer preservation than that of CX. However, dietary supplementation with CX was found to increase the resistance of vitelline membrane in fresh eggs.

Glycerin as a factor for moderating quality changes in table eggs during storage

Abstract. Glycerol, a by-product of biodiesel production, is non-toxic to humans and the environment. With the current increase in the demand for fuels obtained from biomass, the amount of glycerine waste production is increasing. There are many ways to dispose this substance (in pharmaceuticals, cosmetics, and in chemical industry), but its utilization is still insufficient. Therefore, the aim of this study was to assess the possibility of limiting quality changes in table eggs during storage by coating the shells with a glycerol solution. The material used in this research consisted of 270 table chicken eggs collected on the same day. On the first day of the experiment, quality traits of 30 eggs were evaluated (initial control group). The remaining 240 eggs were divided into two equal groups: control (eggs that were not subjected to any treatment) and experimental (eggs that were coated with a 5 % aqueous solution of glycerol). The eggs were placed on transport trays and stored at 14 ∘C and 70 % humidity. Quality evaluations were carried out after 14 and 28 days of storage. The depth of the air cell, mass and specific gravity of the egg, the shell characteristics (water vapour conductance, strength, mass, thickness, and density), and the content traits (pH of the albumen and yolk, Haugh units, and colour and weight of the yolk) were evaluated. The results obtained suggest that the use of glycerine may contribute to slowing adverse changes in egg quality during storage by limiting CO2 removal from the egg content, which allows the egg to maintain albumen structure. Due to the fact that glycerine is a safe, cheap, and easy-to-apply substance, its large-scale use in poultry raw material storage seems to be a very real possibility.

Quality and mineral composition of eggs from hens supplemented with copper-lysine chelate

Abstract. The aim of study was to evaluate the quality of hen eggs influenced by supplementation of copper with lysine chelate (CHL). The material consisted of eggs from two groups of Hy-Line Brown laying hens aged 300 days. Group I, negative control (NC), did not receive any additives. The hens from group II were treated with CHL at a dose of 30 mg Cu L−1 with drinking water. After 4 weeks of supplementation, 60 eggs from each group were randomly collected for quality analysis. The characteristics of the whole egg and its individual elements (shell, yolk, and albumen) were evaluated. The supplementation of CHL increased the egg weight, as well as the weight and height of albumen. There were no changes in the shell strength parameters, and its darker color may increase potential consumer acceptance, but requires confirmation by sensory analysis of the eggs. The copper addition was relatively small, but even this dose caused some changes in egg quality. Little changes in the mineral composition of individual elements of the eggs have been reported. It is therefore very important to continue research to find the smallest effective dose of this micronutrient, to study the duration of time it should be given in order to obtain the best quality of eggs, and to minimize the mineral disorders in organisms.

Protracted volitional spawning of pinfish Lagodon rhomboides and changes in egg quality and fatty-acid composition throughout the spawning season.

Spawning performance of pinfish Lagodon rhomboides without use of hormonal aids was monitored over an extended season. Nearly three million eggs were obtained from 75 spawns collected over a 90-day consecutive period from a single population of four brood fish (1M:1F). A mean ± s.d. batch fecundity of 30·27 ± 22·64 eggs g-1 female was estimated with 98·0 ± 0·06% of the batch composed of floating eggs which were 1·04 ± 0·04 mm in diameter and 85·71 ± 27·59% fertile. Floating eggs successfully hatched 54·65 ± 29·13% of the time which yielded larvae that were 2·59 ± 0·24 mm in length. Fatty acids within floating eggs were largely represented by polyunsaturated fatty acids (45·30 ± 2·14% of total fatty acids) of which linoleic acid [(c18:2n-6cis) 3·49 ± 1·69% trifluoroacetic acid (TFA)] and docosahexaenoic acid (DHA) [(c22:6n-3) 28·47 ± 1·48% TFA] represented the majority of fatty acids for n-6 and n-3 polyunsaturated fatty acids, respectively. The strongest correlations between fatty acids and hatching success and larval survival to first feeding were observed for the DHA:EPA (eicosapentaenoic acid; c20:5n-3) ratio and total n-6 polyunsaturated fatty-acids levels, respectively. These data demonstrate potential for producers to rely on natural spawns for extensive egg production and provide a baseline for future development of natural spawning protocols of captive L. rhomboides.

Age-Related Changes in Egg Quality of Hy-Line Brown Hens

The present study was conducted to monitor age-related changes in egg quality during the entire production cycle of laying hens. Thirty eggs were sampled from the commercial farm on a weekly basis for egg analysis. In order to increase in confidence in sampling, farm personnel were educated to collect the eggs from the pre-determined cages during the whole period and all layers were subjected to an identical farm management and fed a commercial layer diet. In total, 1,470 eggs were sampled and transported to the laboratory of Korea Institute for Animal Products Quality Evaluation. The parameters for egg quality included egg weight, eggshell color, eggshell breaking strength, eggshell thickness, Haugh unit and yolk color. It was shown that egg weight increased as the hen aged. Eggshell breaking strength gradually decreased, but eggshell thickness was randomly scattered without showing any age-related trends during the laying period. The intensity of eggshell color kept relatively constant while yolk color increased with age. Finally, Haugh unit as an indicator of freshness of eggs was consistently decreased as the hens aged. In this study, we noticed that eggshell breaking strength and egg weight were negatively correlated (r= - 0.500, p 0.50), but marginally and positively correlated with egg weight (r = 0.248, p = 0.082). It is concluded that among the various egg quality parameters analyzed, egg weight, eggshell breaking strength or Haugh unit reduced as the hens aged. Further study is needed to include various parameters of egg quality such as chemical or nutritional composition which will provide more insight into the age-mediated changes in egg quality.

Analysis of changes in egg quality of broiler breeders during the first reproduction period

AbstractIn reproductive flocks of poultry it is very important to obtain a large number of eggs with normal structure, optimal morphological composition and interior quality. These elements have very significant influence on the biological value of the egg, which determines normal development of the embryo. The aim of the study was to analyse the physical characteristics, morphological composition and quality of individual components of the eggs of Cobb 500 broiler breeders during the first year of reproduction. The research material was hatching eggs (280 pcs), whose quality was assessed 7 times in the reproductive season at 5-week intervals. The eggs were examined when the hens were aged 26, 31, 36, 41, 46, 51 and 56 weeks (40 eggs for each age). The following characteristics were evaluated: egg weight (g); egg shape index (%); egg specific gravity (g/cm3); shell thickness (mm); average number of pores in the eggshell (pcs/0.25 cm2); yolk, white and shell weight (g) and their percentage in the egg mass; yolk index (%) and the number of Haugh units. The investigations proved that as the reproductive season of hens progressed, the weight of their eggs increased. Above all, this was due to the increase in the yolk weight, because its percentage in the egg weight rose with bird age, whereas the percentage of the white decreased. However, as the reproductive season progressed the quality of both the yolk and white deteriorated. No negative relationship between the age of hens and shell quality (weight, thickness) was observed. Only when the birds were aged 56 weeks, the shell thickness was found to be significantly smaller.

Egg Quality of Japanese Quail Depends on Layer Age and Storage Time

The aim of the study was to analyse egg quality changes of Japanese quail during the reproductive season and after several days of storage. A significantly higher egg weight was recorded in week 9 than in week 25 and week 31 of age ofbirds. The egg specific gravity value of eggs also decreased with the age of quails. The smallest yolk weight and its percentage proportion in egg mass were observed in week 25. Eggs laid in weeks 9 and 25 were characterised by similar and lower (P < or = 0.05) white weight in comparison to those examined on the last date. The highest white proportion in egg weight was recorded during the 25th week. The value of this trait was similar or smaller on the remaining dates. Similar and lower values of the white index and Haugh units, in comparison with the first date, were determined in eggs laid on weeks 25 and 31, whereas similar and greater eggshell thickness than in the 9th week of age was recorded on the last two dates of examination. Lower (P < or = 0.05) egg weight was observed after 5 and 8 than after 0 (measured on the day of laying) days of storage. Likewise, smaller egg specific gravity was recorded after three consecutive periods of storage in comparison with the eggs examined on the day of laying. Eggs examined after 3, 5 and 8 days of storage, in comparison with those stored for 0 days, were characterised by lower yolk index. Significantly smaller weight and white index than after 0 days were determined in eggs stored, respectively, for 5 and 8 as well as for 3, 5 and 8 days. Similarly, smaller numbers of Haugh units were determined after 3 consecutive storage periods in comparison with the eggs examined on the day of laying. Eggs stored for 0 and 3 days were characterised by a greater eggshell weight than those examined after 5 and 8 days. The weight of Japanese quail eggs decreased significantly from day 5 onwards, whereas the egg specific gravity-- from the 3rd day of storage. Yolk and white quality began to deteriorate already after 3 days of egg storage. It appears, therefore, that egg storage of Japanese quails before hatching lasting more than 3 days in the analysed conditions deteriorated the eggshell quality and internal egg traits.