Quality Of Shell Eggs Research Articles

44. Effect of the breeding system of laying hens on the microbiological quality of shell eggs

44. Effect of the breeding system of laying hens on the microbiological quality of shell eggs

The Effect of Feeding Hens a Peanut Skin-Containing Diet on Hen Performance, and Shell Egg Quality and Lipid Chemistry

Peanut skins are a considerable waste product with little current economic value or use. We aimed to determine the dietary effects of peanut skins on layer production performance and egg quality and chemistry of the eggs produced. Two hundred commercial hens were randomly assigned to four treatments (five replicates) and fed ad libitum for 8 weeks: conventional control diet, diet containing 24% high-oleic peanut (HOPN), diet containing 3% peanut skin (PN Skin), and a diet with 2.5% oleic acid (OA). Hens fed the HOPN diet had significantly reduced body weights relative to the control and PN Skin treatments, producing fewer total eggs over the 8-week experimental period. Eggs weights were similar between the control and PN Skin treatments at weeks 2 and 4, while eggs from the PN Skin treatment group were heavier than other treatments at weeks 6 and 8 of the experiment. Eggs produced from the HOPN treatment had reduced saturated fatty acid (FA) content in comparison to the other treatment groups, while similar between PN Skin and control eggs at week 8 of the experiment. This study suggests that PN skins may be a suitable alternative layer feed ingredient.

Spectroscopic approaches for non-destructive shell egg quality and freshness evaluation: Opportunities and challenges

Shell egg quality and freshness are traditionally assessed by destructive laboratory-level methods, thus restricting the possibilities to be easily guaranteed in the industrial chain. Non-destructive techniques are therefore of paramount importance, giving accuracy, speed, and instantaneous results. Among these techniques, spectroscopy is promising because it would allow the development of on-line applications for shell egg grading, with clear benefits for both industries and consumers. However, there are still few works in the literature about this topic. Thus, this review presents recently published (years 2015–2020) applications of spectroscopy methods (i.e., VIS-NIR, NIR, Raman, microwaves, hyperspectral imaging, pulsed IR thermography) to the non-destructive assessment of shell egg quality and freshness, with the aim of boosting the research in this field giving some directions for the fulfilment of industrial needs. Indeed, spectroscopic techniques have been proven to be useful tools for the evaluation of shell egg quality and freshness. The advances in instrumentation and data analysis allow to predict shell egg quality by non-destructive, fast, and environmentally friendly approaches. However, the industrial implementation still requires robust calibration transfer to simplified hand-held systems for low-cost and easy use.

Laying hen biodiversity: a study on the effect of age on the yield performance and quality of eggs produced by two Italian purebred hens

Submitted 2020-07-24 | Accepted 2020-08-10 | Available 2020-12-01 https://doi.org/10.15414/afz.2020.23.mi-fpap.296-304 Yield performance and external and internal quality traits of eggs laid by two Italian purebreds, Ermellinata di Rovigo (ER) and Pepoi (PP) were studied at 36 and 50 weeks of age. Daily egg production and egg traits were evaluated by a factorial model (2 x 2) with genotype and age as main effects and their interaction. The daily laying rate was similar between the breeds and the hen-day egg mass was higher (p<0.01) for ER than for PP. The ER eggs differed (p<0.01) from PP eggs with higher egg weight, yolk and albumen weight, and a more coloured eggshell with lower L, higher a* and b*, and lower eggshell thickness. PP showed more (p<0.05) inclusion of albumen than yolk in comparison to ER. With increased hen age, egg weight, eggshell lenght, width, lightness and thickness increased (p<0.01), whereas shape index and a* and b* did not change. Throughout the laying period, the eggs were classified as small (PP) and medium size (ER). With increased hen age, PP eggs were more spherical, ER eggs were more ovoid; yolk and albumen weight increased (p<0.01) in ER, whereas yolk and eggshell weight increased (p<0.01) in PP. The yolk:albumen ratio increased (p<0.01) along with hen‘s age and the Haugh Units and egg inclusions decreased (p<0.01). The ER and PP eggs differed for many egg external traits, which allow to distinguish the eggs by weight, shape, and eggshell colour and for the eggshell thickness and the albumen traits. Keywords: laying hen, local breed, eggshell trait References Altuntaș, E. & Șekeroğlu, A. (2008). Effect of egg shape index on mechanical properties of chicken eggs. Journal of Food Engineering, 85, 606-612. Casiraghi, E. et al. (2005). Influence of weight grade on shell characteristics of marketed hen eggs. In: Proc. European Symposium on the quality of eggs and egg products, WPSA, Doorwerth, The Netherlands, pp. 183-188. Cassandro, M. et al. (2014). Conservazione e caratterizzazione delle razze avicole venete - Programma Bionet. Rete regionale per la conservazione e caratterizzazione della biodiversità di interesse agrario. Gruppo di lavoro Avicoli. Veneto Agricoltura. Legnaro (PD). Commission Regulation (EC) (2008). Commission Regulation No 589/2008 of 23 June 2008 laying down detailed rules for implementing Council Regulation (EC) No 1234/2007 as regards marketing standards for eggs. Official Journal of the European Union of 24.6.2008, L 163. Di Rosa, A. et al. (2020). Egg quality from Siciliana and Livorno Italian autochthnous chicken breeds reared in organic system. Animals, 10, 864. European Commission (2020). Dashboard Eggs. Methods of production communicated according to Commission implementing. Retrieved July 20, 2020 from http://ec.europa.eu/info/sites/info/files/food-farming-fisheries/ Giersberg, M.F. et al. (2020). The dual-purpose hen as a chance: avoiding injurious pecking in modern laying hen husbandry. Animals, 10, 16. González Ariza, A. et al. (2019a). Sensory preference and professional profile affinity definition of endangered native breed eggs compared to commercial laying lineages’eggs. Animals, 9, 920. González Ariza, A. et al. (2019b). Non-parametrical canonical analysis of quality-related characteristics of eggs of different varieties of native hens compared to laying lineage. Animals, 9, 153. Hadinia, S. H. et al. (2020). Post-photostimulation energy intake accelerated pubertal development in broiler breeder pullets. Poultry Science, 99, 2215-2229. Hidalgo, A. et. al. (2008). A market study on the quality characteristics of eggs from different housing systems. Food Chemistry, 106, 1031-1038. Hy-Line International (2020). Commercial Layers. Management Guide. Retrieved May 18, 2020 from https://www.hyline.com. Lordelo, M. et al. (2020). A comparison between the quality of eggs frpom indigenous chicken breeds and that from commercial layers. Poultry Science, 99, 1786-1776. Nowaczewski, S. et al. (2013). Egg morphometry and eggshell quality in ring-necked pheasant kept in cages. Annals of Animal Science, 13, 531-541. Odobasi, A.Z., et al. (2007). Changes in brown eggshell color as the hen ages. Poultry Science, 86, 356-363. Philippe, F.X. et al. (2020). Comparison of egg production, quality and composition in three production systems for laying hens. Livestock Science, 232, 103917. Rizzi, C. (2020). Yield performance, laying behaviour traits and egg quality of purebred and hybrid hens reared under outdoor conditions. Animals, 10, 584. Rizzi, C. & Chiericato, G.M. (2005). Organic farming production. Effect of age on the productive yield and egg quality of hens of two commercial hybrid lines and two local breeds. Italian Journal of Animal Science, 4 (suppl.3), 160-162. Rizzi, C. & Chiericato, G.M. (2010). Chemical composition of meat and egg yolk of hybrid and Italian breed hens reared using an organic production system. Poultry Science, 89(), 1239-1251. Rizzi, C. & Marangon, A. (2012). Quality of organic eggs of hybrid and Italian breed hens. Poultry Science, 91, 2330-2340. Zeidler, G. (2002). Shell egg quality and preservation. In Bell, D. & Weaver, W.D. jr. Chicken meat and egg production. (5th ed.). Norwell, Massachusetts, USA: Kluwer Academic Publishers (pp. 1199-1217).

The effect of natural zeolite as feed additive on performance and egg quality in old laying hens

This experiment was aimed to use natural zeolite as a feed additive to diet in old laying hens. 36 laying hens of ISA White strain were used, at age of 72 week. The hens were divided into three treatments and each treatment consisted of six replicates with tow hens each. A standard basic ration was used consisting of maize and soybean meal, and the zeolite was added according to the design of the experiment as follows, without zeolite (control T1), +0.5% zeolite (T2) and +1% zeolite (T3). The experiment lasted for 6 weeks. The collected data of performance and egg quality parameters were evaluated of 3 week basis period (1st period 72 -75 week, 2nd period 75 -78 week) and the entire period (72 -78 week). Results indicated that there was no significant effect of adding natural zeolite on the studied performance parameters feed intake (g/hen/d) and feed conversion ratio (g/g) or on the egg production (%), egg weight (g/hen) and egg mass (g/hen/d). However, it must be noted that the hens fed with zeolite at level of +0.5 and +1% showed a higher (p ˃ 0.05) egg productivity comparing to hens without zeolite. Regarding the egg quality parameters, no significant effect were observed between the treatments. However, there were only significantly improvement in egg shell ratio (%) and egg shell density (mg/cm2) when the data of 72 - 78 week were pooled and analyzed. In this study, the zeolite supplementation showed no effects on blood plasma composition. In conclusion, the adding of natural zeolite at inclusion rate of 1% had positive effect on egg production and improved the shell egg quality of old laying hens.

THE INFLUENCE OF LIQUID CALCIUM SOURCE ON EGGSHELL QUALITY

It is estimated that the world’s population will enlarge by 25% by the middle of this century, resulting in the food production increase by at least 60%. Intensifying egg production is one of the most affordable solutions to provide animal protein. Among many other efforts to improve the quality of eggs, special attention is paid to attempts to provide a better endurance and strength of eggshell, due to the fact that the production of eggs with broken, cracked or soft shells incurs significant economic losses. One of the most important factors to achieve this goal is careful adjustment of calcium in the diet of laying hens, but the nutritional role of calcium is closely linked to that of phosphorus and the effect of vitamin D.
 The aim of the experiment was to determine whether two different nutritional supplements of calcium, applied in drinking water of laying hens for two weeks have any significant influence on the shell egg quality. Statistically very significant difference in egg production was observed in the treatment with the product containing calcium and phosphorus. On the other hand, the product consisting of calcium and vitamin D3 had no beneficial impact on the egg parameters. 
 Based on the obtained results and literature data, it can be concluded that the amount and source of calcium in the diet of laying hens is a very complex and not fully solved issue. Therefore, especially keeping in mind the duration of the experiment, additional research is needed on this subject.

Assessment of the relationship between ovomucin and albumen quality of shell eggs during storage

Ovomucin is known to be critical for keeping the high quality and freshness of thick albumen, but there is lack of understanding on the dynamics changes of this important protein during storage. This study aimed to investigate the relationship between ovomucin content and egg freshness during storage. Firstly, the viscoelasticity of albumen was shown to be much higher than that of ovomucin-depleted albumen from rheological analysis results, indicating that ovomucin is an important component in maintaining the natural viscoelasticity of albumen. Then, the ovomucin content determined by ELISA method was compared to albumen pH, Haugh unit (HU), and yolk index in terms of egg white quality and to the time of storage in terms of egg freshness at 4°C, 25°C, and 37°C, respectively. Results of the transformation kinetic showed a decrease in ovomucin content with prolonged storage time (P ≤ 0.01). Correlation analysis showed a high positive correlation between ovomucin content and HU (P ≤ 0.01) and a high negative correlation between ovomucin content and the albumen pH (P ≤ 0.01) at the test temperatures. We therefore conclude that ovomucin content in albumen can be used as an index for egg freshness. At last, predictive models of the equivalent egg age (4°C and 25°C) for evaluating the egg freshness were established by means of exponential regression model with ovomucin content as the variable. These results can provide a theoretical and technical basis for the storage and fresh evaluation of shell eggs.

MORTALITY, PRODUCTION AND QUALITY OF EGGS OF DIFFERENT REARING SYSTEMS

ABSTRACT The conventional production of eggs in cage systems is intense and compromises the laying hens welfare. More demanding consumer markets have been pushing to abolish the use of cages and thus provide better welfare in poultry laying. This research evaluated the mortality, production, and egg quality of two alternative production systems (free-range and organic free range free-range) and compared them with the conventional system. The research was carried out in two commercial poultry farms and the variables egg weight, shell egg resistance, Haugh unit, mortality and production were recorded during eight months. The results showed that the conventional system presented better production, lower mortality and better shell egg quality. The alternative systems had better internal egg quality. Alternative systems had greater variability in outcomes and problems with disease control, which indicate greater difficulty for proper management.

Prevalence and Antimicrobial Resistance of Enterobacteriaceae in Shell Eggs from Small-Scale Poultry Farms and Farmers' Markets

Public health concerns over the emergence of antimicrobial resistant bacteria have increased recently. The purpose of this study was to investigate the prevalence of antimicrobial resistant Enterobacteriaceae in shell eggs purchased from small poultry farms and farmers' markets. A total of 504 eggs were pooled to make 252 composite samples, consisting of 2 eggs per composite. The microbial quality of shell eggs was determined by standard quantitative, biochemical, and PCR techniques. Susceptibility to 13 antimicrobial agents was determined by the Kirby-Bauer disk diffusion technique, and results were interpreted based on Clinical and Laboratory Standards Institute values. Shell eggs and egg contents were positive for Escherichia coli (11.9 and 5.2%, respectively), Enterobacter (9.1 and 7.9%), and Serratia (11.5 and 4.8%). Salmonella was isolated from 3.6% of egg shells but not from egg contents. Mean (±SD) Enterobacteriaceae levels (4.4 ± 2.0 log CFU per eggshell) on shell eggs from poultry farms was significantly higher (P ≤ 0.05) than that on shell eggs from farmers' markets (2.1 ± 1.3 log CFU per eggshell). Of the 134 isolates recovered, resistance among isolates from farm and market shell eggs to erythromycin was most common (48.5 and 32.8%, respectively) followed by ampicillin (44.8 and 17.2%), and tetracycline (29.9 and 17.2%). The multiple antibiotic resistance index value for E. coli and Pantoea was 0.62, and that for Salmonella and Klebsiella terrigena was 0.08, indicating that Enterobacteriaceae in shell eggs can be resistant to multiple antimicrobial agents. These data reveal that shell eggs from small poultry farms and farmers' markets can harbor antimicrobial resistant pathogenic and commensal bacteria. Thus, failure to properly handle shell eggs poses a potential health hazard to consumers.

Uso de aditivo alimentar equilibrador da flora intestinal em aves de corte e de postura

RESUMO: Aspectos gerais sobre a utilização de aditivos zootécnicos equilibradores da flora intestinal em rações de aves de corte e de postura foram abordados nesta revisão, destacando-se a utilização de prebióticos, especialmente dos mananoligossacarídeos (MOSs), os quais promovem o crescimento das populações microbianas que melhoram as condições luminais. A utilização de aditivos equilibradores da flora intestinal tem revelado melhorias na integridade do epitélio intestinal (aumento da altura e largura das vilosidades), no desempenho (melhora na produção e conversão alimentar) e na qualidade do produto final (qualidade da casca dos ovos). Esta revisão objetivou abordar também aspectos relacionados às características, ao mecanismo de ação, além dos efeitos benéficos da utilização desses aditivos alternativos aos antibióticos na avicultura de corte e de postura, incluindo codornas japonesas.

Development of Antimicrobial Coatings for Improving the Microbiological Safety and Quality of Shell Eggs

This study was conducted to develop antimicrobial coatings to decontaminate and prevent cross-contamination of shell eggs. Egg shells were inoculated with nalidixic acid-resistant Salmonella enterica Enteritidis strains OB030832, OB040159, and C405 and treated with antimicrobial coatings. Polylactic acid served as a nonedible polymer, and chitosan served as an edible polymer carrier of natural antimicrobials, including nisin, allyl isothiocyanate (AIT), lauric arginate ester (LAE), and organic acids. Increases of AIT concentrations or addition of nisin to AIT in either the polylactic acid or chitosan coating solutions resulted in greater reductions of Salmonella. Chitosan coatings with 0.1, 0.5, and 1.0% LAE reduced Salmonella by 1.7, 2.5, and 5.2 log CFU/cm(2), respectively. Shell eggs treated with 1.0 and 0.5% LAE in chitosan coatings had nondetectable Salmonella cells (< 0.5 log CFU/cm(2)) after 3 and 7 days of storage at 7°C, respectively, and no outgrowth was observed up to 28 days. Coating treatments significantly reduced weight loss of shell eggs during 12 weeks of storage at 7 or 4°C. This study demonstrates an alternative and effective intervention technology for decontaminating shell eggs and provides an alternative approach to reduce possible recalls and outbreaks associated with pathogen contamination on shell eggs and in egg products.

Effects of mycotoxin-contaminated diets and deactivating compound in laying hens: 2. Effects on white shell egg quality and characteristics

An experiment was conducted to determine the effect of dietary inclusion of Mycofix Select (Biomin GmbH, Herzogenburg, Austria) on discrete egg parameters and quality characteristics of hens fed mycotoxin-contaminated diets (aflatoxin; AFLA) and deoxynivalenol (DON)) during a 10-wk trial. A 4 × 2 factorial design was used with 4 contamination levels: control, low (0.5 mg/kg of AFLA + 1.0 mg/kg of DON), medium (1.5 mg/kg of AFLA + 1.5 mg/kg of DON), and high (2.0 mg/kg of AFLA + 2.0 mg/kg of DON) with or without the inclusion of mycotoxin deactivating compound. Three hundred and eighty-four 25-wk-old laying hens were housed 3 per cage. Birds were fed contaminated diets for a 6-wk phase of toxin administration followed by a 4-wk recovery phase, when all birds were fed mycotoxin-free diets. Parameters evaluated included egg weight, Haugh unit value, specific gravity, eggshell thickness, egg shape index, and relative albumen and yolk weights. Albumen height and Haugh unit value were depressed (P < 0.05) at the high mycotoxin level 2 wk postinclusion. Egg weight was significantly reduced (P < 0.05) with the high toxins level by the third week of toxin administration and remained throughout the study during toxin administration. Egg shape index indicated a variation (P < 0.05) in shape with all toxin levels compared with the control. Relative yolk weight was decreased (P < 0.05) by the high toxin level. An interaction existed between the deactivating compound inclusion and toxins level with regard to specific gravity. Following the toxin phase, the deactivating compound inclusion increased (P < 0.05) egg specific gravity in the control and low toxin groups whereas a decrease (P < 0.05) was observed at the high toxin level. These data indicate that mycotoxins present in feed can reduce egg quality, size, yolk weight, and alter egg shape and that inclusion of a mycotoxin deactivating compound can ameliorate some of the negative effects of mycotoxin consumption.

Maximizing carbon dioxide content of shell eggs by rapid cooling treatment and its effect on shell egg quality

Rapid cooling of shell eggs using liquid CO₂ has been shown to cool eggs to 7°C within minutes, as opposed to days required by traditional cooling treatments. This quick-cooling technique is component in the maintenance of egg quality and extended shelf life beyond the current 30- to 45-d period. The hypothesis for the current study was that maximizing CO₂ content of the eggs during cooling may increase Haugh units and thus extend shelf life (physical quality factors). The objective of this study was to maximize CO₂ content of shell eggs during rapid cooling with liquid CO₂ and determine its effect on egg quality during 12 wk of refrigerated storage. Three cooling conditions selected for the study were -45°C for 18 min (treatment A), -60°C for 15 min (treatment B), and -75°C for 12 min (treatment C). After rapid-cooling treatment, it took approximately 25 min for the internal temperature of eggs to equilibrate to 7°C. The Haugh units of the rapidly cooled eggs were significantly higher than the traditionally cooled (control) eggs. After 12 wk of refrigerated (5-7°C) storage, control eggs were only 37% AA-grade, 57% A-grade, and 6% B-grade. In comparison, all the rapidly cooled eggs averaged to 80% AA-grade and 20% A-grade. After 6 wk, the average quality of control eggs reduced to grade A, whereas rapid cooling treatment was able to maintain AA quality up to 12 wk. The CO₂ content of the rapidly cooled eggs (1.8 mg of CO₂/g of albumen) showed no difference between treatments A, B, and C, but it was significantly higher than the control (1.3 mg of CO₂/g of albumen). In addition, the vitelline membrane strength of the control decreased 65% during storage and was between 30 and 50% of the vitelline membrane strength of CO₂-cooled eggs at 12 wk. Rapid cooling with liquid CO₂ extends shelf life of shell eggs.

Effect of various refrigeration temperatures on quality of shell eggs

The objective of this study was to evaluate the effects of low storage temperatures on shell egg quality. Approximately 2100 shell eggs were collected and stored at - 1.1, 0.6, 2.2, 3.9, 5.6 and 7.2 °C for up to 4 weeks. Eighteen eggs at each storage temperature were evaluated after 0, 2, 7, 14, 21 and 28 days of storage. Haugh units (HU), yolk index (YI), albumen pH (pHA), yolk pH (pHY) and angel food cake density (CD) were measured. Shell egg quality tended to be preserved better at below 2.2 °C, as high HU and YI values relative to eggs stored at 7.2 °C were determined on day 28. However, storage at - 1.1 °C tended to cause the opposite effect, especially highly declined HU values over time. Significantly different HU values of shell eggs were measured after 14 days of storage, with eggs stored at 0.6 and 2.2 °C having the highest HU values, 80.42 and 77.97 respectively. A lower temperature limit for shell egg storage could be established between 0.6 and 2.2 °C, as both temperatures showed the highest HU values, 77.88 and 77.60 respectively, after 28 days of storage.

Quality of Shell Eggs Pasteurized with Heat or Heat‐Ozone Combination during Extended Storage

The physical quality and functionality of shell eggs, pasteurized with heat or a combination of heat and ozone, were assessed during eight weeks of storage at 4 or 25 °C. Shell eggs were treated as follows: (1) immersion heating that mimics commercial pasteurization processes (egg internal temperature of 56 ± 0.1 °C for 32 min), or (2) a newly developed combination process comprised of heating (56 ± 0.1 °C, internal, for 10 min) followed by gaseous ozone treatment. Eggs were tested for yolk index, Haugh units, albumen pH, albumen turbidity, and percent overrun. Additionally, albumen samples were assayed for lysozyme activity and free sulfhydryl group content, and were analyzed using differential scanning calorimetry and Fourier transform infrared (FTIR) spectroscopy. Both processed and unprocessed eggs maintained superior quality when stored at 4 °C, as opposed to 25 °C. Pasteurization, regardless of method, led to superior maintenance of Haugh units during storage but also increased albumen opacity and decreased albumen overrun. Detrimental effects on quality markers were more severe in heat-pasteurized eggs than those treated with the ozone-based process. Pasteurization of shell eggs by either process did not affect lysozyme activity or sulfhydryl group content. Changes in protein secondary structure, as indicated by FTIR analysis, suggest that the ozone-based process is less damaging to albumen proteins than is the heat-alone process. In conclusion, heat-ozone pasteurization, by virtue of its less severe heat treatment, yields a safe final product that more closely resembles untreated shell eggs.

Combination of Super Chilling and High Carbon Dioxide Concentration Techniques Most Effectively to Preserve Freshness of Shell Eggs during Long‐Term Storage

This study was made to examine the combined effects of stored temperature and carbon dioxide atmosphere on shell egg quality. The shell eggs were packed into polyethylene terephthalate/polyethylene (PET/PE) pouches and stored at 0 degrees C (super chilling), 10 degrees C, and 20 degrees C, respectively for 90 d. The atmospheric carbon dioxide concentration was controlled to obtain the 3 concentration levels of high (about 2.0%), medium (about 0.5%), and low (below 0.01%). Changes in Haugh unit (HU) values, weakening of vitelline membranes, and generation of volatiles were analyzed to evaluate the freshness of shell eggs. Results showed that, compared with the other combinations, the technique of super chilling and high carbon dioxide concentration enabled shell eggs to be most effectively stored for 90 d, based on estimations of the statistical significances of differences in HU values, and on maintaining the initial HU values during storage. In addition, the storage of shell eggs using this combination technique was found to significantly prevent the weakening of the vitelline membrane based on the estimations of numbers of eggs without vitelline membrane breakage when eggs broke, and significantly lowered the incidence of hexanal in the yolk from exposure to the gas chromatographic-mass spectrometric analyses of volatiles. Thus, these results confirmed that the combination of super chilling and high carbon dioxide concentration was the most effective technique for preserving shell eggs during a long term of 90 d compared with other combination techniques.

Granulometria do calcário no desempenho e qualidade da casca de ovos de codornas japonesas

This experiment evaluated limestone particle size of diet on performance and shell quality of japanese quails. The experimental design used was completely randomized with five treatments (five different particle sizes of limestone) and five replicates of 16 birds each in a total of 400 birds. The treatments were: T1 – Diets with 100% of the limestone coarse; T2 – diets with 70% of limestone coarse and 30% fine; T3 – diets with 30% of limestone coarse and 70% fine; T4 - Diets with 100% of the limestone fine and T5 – Diets with 100% of medium limestone. The experimental diets were formulated to meet NRC (1994) nutritional requirements. The treatment of 100% fine particle size improved egg production and bird performance compared to the treatment with 100% medium particle size. There was no effect of limestone particle size on shell quality of quail eggs. The fine or coarse limestone particle size can be used in diets of laying quails. The medium limestone particle size is not recommended on laying Japanese quail diets. KEY WORDS: Limestone, particle size, japonese quails, egg production, shell egg quality.

Microbial Quality of Cool Water Washed Shell Eggs

3 Abstract: A study was conducted to examine the effects of cool water washing on the microbial quality of shell eggs. Six dual tank wash water temperature schemes were examined for their ability to reduce naturally occurring aerobic bacteria and inoculated Salmonella Enteritidis (SE). The wash water schemes were: T1= 48.9 C; T2 = 48.9 C, 23.9 C; T3 = 48.9 C, 15.6 C; T4 = 23.9 C; T5 = 15.6 C; and T6 = 23.9 C, 15.6 C. All wash o o o o o o o o o water tanks were maintained from 10.5-11.5 pH throughout the study. Eggs were exposed to the wash water temperature schemes in a pilot egg washer with recirculating wash water tanks. The total amount of time eggs were exposed to the wash water combinations was 60 s. Following washing, all eggs were sprayed with a 48.9 C, 200 ppm chlorine rinse solution. Eggs were stored and sampled for 9 wks. External aerobic o populations were lowest for T1 (typical U.S. wash water configuration), followed by T2 and T3. Aerobic surface contamination was greatest in T5 eggs. All treatments reduced SE levels in a similar manner as detected by shell and membrane emulsion and egg contents pools after enrichment. Commercial application of cool water shell egg processing will be investigated to determine the potential of thi s technology to enhance the safety and quality of shell eggs.

Effects of cryogenic cooling of shell eggs on egg quality

This study was conducted to investigate the effects of cryogenic cooling on shell egg quality. Gaseous nitrogen (GN), liquid nitrogen (LN), and gaseous carbon dioxide (GC) were utilized to rapidly cool eggs in a commercial egg processing facility and were compared to traditional cooling (TC). A modified food freezer was attached to existing egg processing equipment in order to expose eggs to the selected cryogen. In Experiment 1, eggs were treated with GN, LN, and TC then stored and tested over 10 wk. Experiment 2 eggs were treated (GC and TC) and evaluated for 12 wk. Quality factors that were measured included Haugh units, vitelline membrane strength and deformation at rupture, and USDA shell egg grades for quality defects. Haugh unit values were greater for cryogenically treated eggs as compared to traditionally cooled eggs (Experiment 1: 73.27, GN; 72.03, LN; and 71.4, TC and Experiment 2: 74.42, GC and 70.18, TC). The percentage of loss eggs in the GN treatment was significantly (P < 0.01) greater than those of the LN and TC treatments. Vitelline membrane strength was greater for the cryogenically cooled eggs versus traditional processing. Vitelline membrane breaking strength decreased over storage time. Vitelline membrane deformation at rupture was significantly (P < 0.05) greater for the cryogenically cooled eggs compared to the traditional eggs in each experiment. Use of the technology could allow for egg quality to be maintained for a longer time, which could increase international markets and potentially lead to extended shelf lives.

The Influence of Rapid Air Cooling and Carbon Dioxided Cooling and Subsequent Storage in Air and Carbon Dioxide on Shell Egg Quality

This study examined the effect of rapid cooling with air and CO2 on shell egg quality over 14 wk. The 240 fresh eggs were initially heated to 47 C for 24 h in an incubator, cooled using rapid air cooling or CO2 cooling, and then stored in air or CO2 in 250-mL jars for 14 wk. The CO2 levels were recorded of the jar atmosphere, of the egg air cell, and of the egg albumen. The Haugh units of each egg, pH, and of albumen from five eggs per group were also recorded. Haugh units are a logarithmic, empirical relationship between albumen height and egg weight (Stadelman, 1995).Haugh units for the control eggs averaged 70.8 over 10 wk of the study. The control eggs were of such poor quality that they could not be sampled after 10 wk. The air-cooled and CO2-stored eggs averaged 70.3 Haugh units over the 14-wk storage period; however, the egg quality significantly deteriorated after 10 wk. The CO2-cooled and CO2-stored eggs averaged 75.9 Haugh units over the 14 wk study, with no observable decrease in quality.Rapid air-cooling produces a lower quality egg than rapid cooling with CO2. Subsequent storage of rapidly air-cooled eggs in CO2 may increase shelf life, but Haugh units were not statistically different from rapid air-cooled eggs. CO2-cooling and subsequent storage in CO2 increased Haugh units. The shelf life of shell eggs could be extended to greater than 14 wk when the eggs were CO2-cooled and CO2-stored.