Shell Quality Research Articles

Effect of hen age, environmental temperature, and oviposition time on egg shell quality and egg shell and serum mineral contents in laying and broiler breeder hens

The aim of the study was to evaluate egg shell quality characteristics, mineral content in the egg shell, and serum mineral concentration during the egg formation process as influenced by oviposition time and ambient temperature at the beginning and end of the laying cycle in laying hens and broiler breeders. Egg shell quality deteriorated significantly at the higher temperature and was lower in broiler breeders than in laying hens. The Ca (P = 0.047) and P (P = 0.018) contents of the egg shell were significantly higher at the higher temperature. The highest (P = 0.028) shell Ca content (352 g/kg) was in eggs laid in the morning, but the highest P (P = 0.030; 1.43 g/kg) and Mg (P = 0.001; 3.88 g/kg) contents were in eggs laid in the afternoon. Broiler breeder egg shells contained significantly more P (P = 0.004) and Mg (P = 0.001) than did those from laying hens. Serum Ca and P levels remained constant throughout the day whereas serum Mg and Zn levels decreased, the rate of decrease in Zn content being the same in all treatments, but with the amounts being greater in laying hens than broiler breeders. The results demonstrate that shell quality characteristics are more severely affected by different factors implemented in this trial compared to the shell mineral composition and especially compared to the serum mineral content.  

Effect of supplementing microbial phytase in diets containing graded concentrations of calcium on performance, shell quality and bone mineral parameters in WL layers

An experiment was conducted to study the effect of supplemental phytase in diets containing graded concentrations of calcium (Ca) and non-phytin phosphorus (NPP) on performance of WL layers. Eight diets with four graded concentrations of Ca (35, 37.5, 40 and 42.5gkg−1) and two concentrations of NPP (3 and 1gkg−1) were prepared. The low phosphorus diets were supplemented with phytase (500FYTkg−1). Each diet was fed ad libitum to 8 replicates consisting of 88 laying chickens each from 25 to 72 weeks of age. Data were compiled and analysed in 3 phases (phase 1, 25 to 40 weeks; phase 2, 41 to 56 weeks; phase 3, 56 to 72 weeks of age) and all the 3 phases as the overall period. The interaction between Ca concentration and phytase supplementation significantly influenced egg production (EP), feed intake (phase 1), egg weight (phase 3), egg mass (phase 2 and 3), feed efficiency (FE) and Ca and P concentrations in tibia ash at 44 weeks of age. Feed intake during phases 2 and 3, egg weight during phases 1 and 3, egg mass during phase 1, body weight during phases 1, 2 and overall period, egg shell defects, shell weight, shell percent and bone mineral parameters at 72 weeks of age were not affected by the interaction. EP, EM and FE improved significantly with increase in dietary Ca concentration from 35 to 37.5gkg−1 in groups fed without phytase and further improvement was not observed at higher concentrations of Ca in diet. While the layer performance in groups fed 35g Ca with phytase supplementation improved similar to those fed ≥37.5gCakg−1 diet without phytase. The layer performance reduced significantly in groups fed diets supplemented with phytase at higher concentrations of Ca (40 and 42.5gCakg−1) compared to those fed 35gCakg−1 suggesting the inhibitory effect of higher dietary Ca concentrations on utilization of phytase phosphorus. Based on the study, it is concluded that WL layers reared in open sided poultry houses in tropical climate require lower intake of Ca (3.32, 3.80 and 4.00gbird−1day−1) when the diets are supplemented with phytase (500FYTkg−1) compared to those fed without phytase (3.58, 4.14 and 4.30gbird−1day−1 during 25–40, 41–56 and 57–72 weeks of age, respectively, during phase 1–3). At higher concentrations of Ca (40 and 42.5gkg−1), response to supplemental phytase appears to be reduced in terms of performance in layers.

Exogenous estradiol improves shell strength in laying hens at the end of the laying period

BackgroundCracked shells, due to age related reduction of shell quality, are a costly problem for the industry. Parallel to reduced shell quality the skeleton becomes brittle resulting in bone fractures. Calcium, a main prerequisite for both eggshell and bone, is regulated by estrogen in a complex manner. The effects of estrogen, given in a low continuous dose, were studied regarding factors involved in age related changes in shell quality and bone strength of laying hens. A pellet containing 0.385 mg estradiol 3-benzoate (21-day-release) or placebo was inserted subcutaneously in 20 birds each of Lohmann Selected Leghorn (LSL) and Lohmann Brown (LB) at 70 weeks of age. Eggs were collected before and during the experiment for shell quality measurements. Blood samples for analysis of total calcium were taken three days after the insertion and at sacrifice (72 weeks). Right femur was used for bone strength measurements and tissue samples from duodenum and shell gland were processed for morphology, immunohistochemical localization of estrogen receptors (ERα, ERβ), plasma membrane calcium ATPase (PMCA) and histochemical localization of carbonic anhydrase (CA).ResultsEstrogen treatment increased shell thickness of both hybrids. In addition, shell weight and shell deformation improved in eggs from the brown hybrids. The more pronounced effect on eggs from the brown hybrid may be due to a change in sensitivity to estrogen, especially in surface epithelial cells of the shell gland, shown as an altered ratio between ERα and ERβ. A regulatory effect of estrogen on CA activity, but not PMCA, was seen in both duodenum and shell gland, and a possible connection to shell quality is discussed. Bone strength was unaffected by treatment, but femur was stronger in LSL birds suggesting that the hybrids differ in calcium allocation between shell and bone at the end of the laying period. Plasma calcium concentrations and egg production were unaffected.ConclusionsA low continuous dose of estrogen improves shell strength but not bone strength in laying hens at the end of the laying period.

How Egg Quality Impacts the Health of Day-One-Chicks?

The main goal of every breeder farm is to get the maximum number of qualified eggs and live chicks per hen and the highest proportion of top quality day-one-chicks. In order to obtain the maximum number of healthy, highly productive chicks, we need to consider not only the variables related to the breeders but also the factors related to eggs quality. Physical characteristics of fertile eggs are key not only to embryonic development and hatchability, but also to the health of chicks during the first week of life. Eggs with low shell quality or low specific gravity are more likely to be penetrated by pathogenic bacteria. The most obvious consequence of such infection is the development of omphalitis, also called yolk sac infection, major cause of disease and mortality in broilers during the first week, as well as a loss of productivity throughout the life of broilers

Preparation and oxidation behavior of Ag-coated Cu nanoparticles less than 20 nm in size

This study examines the oxidation behavior of Ag-coated Cu (Cu@Ag) nanoparticles (NPs) less than 20 nm in size synthesized using a solvothermal method and an immersion process with varying Ag shell quality. The anti-oxidation property of Cu@Ag NPs was strongly dependant on the Ag shell quality.

Isolation of Brachyspira pilocicoli from Gastrointestinal Tract of Commercial Chickens in Khuzestan, South West Iran

Background: Brachyspira pilosicoli is an intestinal spirochete which colonizes in cecum, colon and rectum of the birds. This infection in broiler and laying chicken may cause disorders such as: diarrhea, reduced egg production, pasty vents, fecal staining of egg shells, poor shell quality, pale egg yolks, increased feed consumption, slower growth and poor feed digestion. Objectives: The aim of this study was to isolate and identify B. pilosicoli from broiler and laying chicken. Materials and Methods: This study was conducted by using bacteriological examination and PCR in Khuzestan located in the South West of Iran. Totally 150 samples of broiler chicken feces and 100 samples of laying chicken feces were collected. The samples were cultured on blood agar containing three antibiotics (vancomycin 12.5μg/mL, spiramaycin 25μg/mL and spectinomycin 400 μg/mL).The colonies of intestinal spirochetes were studied by PCR. Results: Intestinal spirochetes were isolated in 21 out of 150 fecal samples of broiler chicken and in 9 out of 100 fecal samples of laying chicken. Species identification of isolates was done by PCR using 16SrRNA gene specific for B. pilosicoli. B. pilosicoli was isolated in 13 out of 21 positive broilers and in 4 out of 9 positive laying chickens. Conclusions: This study showed that B. pilosicoli exists in the broiler and laying chicken in the region. This intestinal pathogen may be considered as a major cause of production threats and economic losses in chicken farms in the region of study.

산란초기의 사료 내 조단백질 수준에 따른 계란 생산성 및 품질에 미치는 영향

본 시험은 산란 초기에 있어 조단백질 수준이 미치는 영향을 조사함으로 산란 초기 사료 내 적정 단백질 수준을 제시하기 위한 목적으로 실시하였다. 공시 동물은 22주령 Hy-Line 갈색계를 이용하여 동일한 면적의 케이지에 모두 4개 처리구에 9반복, 반복당 20수씩 총 720수를 선발하여 2주간 일반 시판 사료로 예비 사육하였으며, 처리구별 산란율과 체중이 유사하도록 재배치한 후 총 12주간 사육하며, 조단백질 수준이 난생산성 및 품질 변화에 미치는 영향을 관찰하였다. 사료 섭취량의 경우 조단백질 수준에 따른 유의적인 차이가 나타나지 않았으나, 조단백질 16% 처리구의 경우 다소 낮은 섭취량을 나타내었다. 산란율에 있어 조단백질 수준에 따른 유의적인 차이가 나타나지 않았으나, 조단백질 16% 사료를 급여할 경우에도 산란율 95% 수준을 유지할 수 있는 결과를 보였다. 난중의 경우, 조단백질 19%를 제외하고, 조단백질 16~18%에서 선형적으로 증가하는 경향을 보였으나, 조단백질 수준에 따른 유의적인 차이가 나타나지는 않았다. 난질 항목에 있어 Haugh unit, 난각 두께 및 강도의 경우 조단백질 수준에 따른 유의적인 차이가 나타나지 않았다. 난황색에서 조단백질 수준에 따른 유의적인 차이가 나타나지 않았으나, 조단백질 수준이 증가할수록 난황색이 옅어지는 경향을 발견할 수 있었다. 따라서 본 연구는 한국사양표준 2차 개정판(2012)에서 규정하고 있는 주요 아미노산(Lys, TSAA, Thr) 수준을 유지하고, 사료 섭취량이 105 g 이상의 조건이라면 조단백질 16% 수준으로도 초기의 난 생산성 및 품질에 큰 문제는 없을 것으로 사료된다. This experiment was conducted to determine optimum levels of dietary crude protein for productivity and egg quality in laying hens during early stage. A total of seven hundred and twenty 24-wk-old Hy-Line Variety Brown layers were randomly assigned to 4 experimental diets varying with 16%, 17%, 18%, and 19% CP and fed the diets for 12 wks. There were no significant differences in egg production, daily egg mass and feed intake among experimental diets. Although no difference was found on egg weight among experimental diets, decreasing levels of dietary crude protein tended to reduce the egg weight. Haugh unit and egg shell quality were not affected by different levels of dietary crude protein. Although there was no difference on yolk color among experimental diets, increasing levels of dietary crude protein slightly reduced the yolk color. It is concluded that laying hens did not need more than 16% CP to maximize egg production.

Assessing the thermo-tolerance potentials of five commercial layer chicken genotypes under long-term heat stress environment as measured by their performance traits

This study was conducted to test the thermo-tolerance ability of five commercial chicken genotypes (Lohmann Brown, LB; Lohmann White, LW; New Hampshire, NH; White Leghorn selected for low feed expenditure, WL-FE and White Leghorn with sex-linked dwarf gene, WL-dw) under long-term heat exposure. Two-hundred forty female chickens were assigned to a completely randomized design in a 5 × 2 factorial arrangements (five genetic groups and two ambient temperatures [thermo-neutral, 18–20 °C; heat stress, 30–32 °C]). Individual eggs were collected on daily basis while egg weight and feed intake were determined on individual and group basis at 28-days intervals, respectively. Shell quality traits were determined at 25, 40 and 56 weeks age. No Genotype × ambient temperature interactions were found except for body weight and egg deformation. Chickens at thermo-neutral temperature produced significantly heavier eggs than those of heat-exposed (60 g vs. 54 g). Hen-housed egg production of chickens in thermo-neutral temperature was significantly higher than those of heat-stressed (76.8 % vs. 66.2 %). Daily egg mass production at thermo-neutral and heat stressed chickens was 46 g and 35.8 g, respectively. Feed consumption in heat-stressed and thermo-neutral chickens was 109 and 80.8 g, respectively. Shell thickness, breaking strength and Haugh unit values were significantly reduced in heat-stressed chickens. Among heat-exposed chickens, the NH had the highest body weight while the LW produced 10 % more eggs than the group average. The heat-induced effect on shell quality traits was lowest in LW chickens. The results indicated that the magnitude of heat stress was breed dependent in which the LB showed poor adaptability to heat stress while both NH and LW genotypes demonstrated better thermo-tolerance ability.

Effects of yeast cell wall on early production laying hen performance

SUMMARY The influence of 2 concentrations of yeast cell wall (YCW), supplied as Safmannan A, at 250 and 500 ppm on early production laying hen performance (21–36 wk) was investigated in this study. A total of 75 Lohmann W-36 replacement pullets, 17 wk old, were distributed among 75 laying hen cages (1 bird/pen). Three treatments were sequentially assigned to an equal number of pens per treatment. The 3 diets mixed were a basal diet only (control) and a basal diet supplemented with 250 or 500 ppm of Safmannan A (YCW 250 and YCW 500). Feed and water were offered ad libitum. Data were collected for period 1 when birds were 21 wk old and hen day egg production was >90%. Treatment YCW 250 resulted in significantly higher egg weight from 21 to 28 wk old and higher than YCW 500 from 29 to 36 wk old. Treatment YCW 250 resulted in a calculated average cumulative liquid egg yield of 5.47 kg/bird over 4 production periods versus 5.29 kg/bird for the control and 5.13 kg/bird for YCW 500. Over the first production period, feed consumed per dozen eggs was significantly lower in treatment YCW 500 versus treatment YCW 250, but not significantly lower than the control treatment. Feed consumption per dozen eggs was not different among treatments for the remainder of the study. Average feed consumed per bird per day and cumulative egg production at any point in time was not different between treatments. Specific gravity, egg shell thickness, egg shell weight, and percent shell weight were significantly higher in hens fed YCW 500 versus YCW 250 at 36 wk of age. Overall, feeding a diet supplemented with 250 ppm Safmannan A improved egg weight and liquid egg yield in early production laying hens, whereas shell quality was improved when feeding Safmannan A at the historically recommended concentration of 500 ppm.

Hatchling length is a potential chick quality parameter in meat type chickens

Like other chick quality parameters, hatchling length is an easy and repeatable quality evaluation parameter for newly hatched chicks. This important trait has a positive correlation with the size of the egg and the chick's weight. The hatchling length is the best indicator of pre-incubation and incubation conditions and for the rate of absorption of yolk after hatching in the body cavity of the chick. Chicks with large lengths have heavier heart weights, liver weights and bursa of Fabricius at hatch. The length at hatch can be measured from the crown to toe and it can be improved by maintaining embryo temperature until internal pipping, proper egg storage conditions, maximum turning of eggs, maintaining the minimum egg weight losses at the 18th day of embryonic development, maintaining ample O2 supply and removal of CO2 through gas exchange programs, improved shell quality and better health of the breeder flock.The yolk does not play any role in the bird's future growth but it can create many disease problems in the bird's life. A bigger, day-old chick has a large residual yolk and a small yolk-free body mass. This characteristic does not play any role in the development and growth during the incubation and post incubation processes. In conclusion, hatchling length offers a fast, repeatable, and non-destructive method to evaluate chick quality.

The effects of a short-term molt method using cassava meal, broken rice, or corn on ovarian regression, bone integrity, and postmolt egg production and quality in older (95 week) laying hens

This study was conducted to determine the ability of different molt diets to induce molt in 95-wk-old hens. The hens were randomly assigned to 4 treatments of 60 birds each: 1) molted by full feeding with broken rice (BROK), 2) corn (CRN), 3) cassava (CASS), or 4) nonmolted control (CONT) for 14 d. At 15 d, all hens were fed a layer diet (17% CP), and production performance was measured for 20 wk. Feed intake was depressed (P < 0.05) in the CASS treatment compared with BROK and CRN treatments during the 14 d. The most significant BW loss occurred in the CASS treatment (21.9%), whereas BROK and CRN treatments were 7.6 and 9.3%, respectively. The CASS treatment resulted in total cessation of egg production within 7 d, whereas those of BROK and CRN treatments decreased to 3.7 and 8.7%, respectively. Ovary weights, oviduct weights, and oviduct lengths of the CASS treatment were not significantly different from those of BROK and CRN treatments (P > 0.05). The weight of spleen and thymus glands, blood heterophil:lymphocyte ratios, bone parameters, and mortality during the 14-d treatment were not affected by treatments. No significant differences were found among treatments for postmolt cumulative egg production, egg weight, feed intake, and mortality. Significant (P < 0.05) improvements in albumen quality were observed in the CASS treatment, although shell thickness of this treatment was reduced (P < 0.05) compared with the CONT treatment in wk 2 after the 14-d treatment. With respect to shell ultrastructural traits, the palisade layer of CASS eggs was shorter (P < 0.05) than that of CONT eggs determined in wk 2 after the 14-d treatment. In addition, evidence of abnormal mammillae was detected in an egg produced by the CASS hens. This research indicates that cassava diets can induce molt in hens. Nonetheless, the technique needs to be adjusted to improve postmolt egg production and shell quality.

Effects of dietary energy and calcium levels on performance, egg shell quality and bone metabolism in hens

This study investigated the effects of dietary energy and calcium levels on laying performance, eggshell quality and bone metabolism of layers. One hundred and sixty-two 19-week-old Hy-Line brown laying hens in 54 battery cages were allocated to one of nine dietary treatments with control, middle and high levels of energy (11.50, 12.68 and 13.37MJ/kg, respectively) and low, control and high levels of calcium (2.62%, 3.7% and 4.4%, respectively) for 60days, using a 3×3 factorial arrangement.Compared with the control energy diet, high- and middle-energy diets increased fat deposition and egg weight, decreased feed intake and bone quality and had no effects on eggshell quality. The high-energy diet reduced the serum phosphate concentration and elevated osteocalcin mRNA expression in the keel bone without increasing osteocalcin protein. Dietary calcium intake did not affect fat deposition, feed intake or egg weight. Low dietary calcium resulted in weaker eggshells and poorer bone quality than that from hens fed the control diet. High dietary calcium increased serum calcium concentration, osteoprotegerin mRNA and osteocalcin protein and inhibited serum alkaline phosphatase activity and decreased its mRNA compared with low or control dietary calcium. The high-energy and high-calcium diet significantly reduced egg production.Compared with the control energy diet, high- and middle-energy diets increased fat deposition but had negative effects on bone metabolic homeostasis. Dietary calcium did not influence fat deposition but a high-calcium diet benefited bone homeostasis, while a low-calcium diet was associated with poorer eggshell quality and bone homeostasis.

Salmonella penetration through eggshells of chickens of different genetic backgrounds

Eggs have been identified as a source of salmonellosis, making the transmission of Salmonella to eggs of great concern to the poultry industry. The goal of this experiment was to determine the ability of Salmonella to penetrate the eggshell of 5 different breeds of noncommercial chicken, Barred Plymouth Rock, White Leghorn, Brown Leghorn, Fayoumi, and Light Sussex, and 1 commercial Lohmann LSL-Lite. Egg weight, breaking force, shell weight, and shell thickness measurements were taken for 30 eggs per breed. A 1 cm in diameter hole was cut out from the narrow end of 30 additional eggs per breed. The shells were filled with plate count agar containing tetracycline and 0.1% 2,3,5-triphenyl terazolium chloride and sealed with paraffin wax. Agar-filled eggs were submerged for 1 min in an overnight culture of tetracycline-resistant Salmonella Heidelberg and incubated at 37°C for 40 h. Eggs were candled and visual colonies were counted and reported as cfu per egg and cfu per gram of shell. The SAS mixed model was used to evaluate differences between breeds for egg quality characteristics and the number of cfu per egg and per gram of shell. Commercial layers (62.6 g) and Barred Plymouth Rock (61.5 g) produced the largest eggs, whereas Fayoumi (47.1 g) produced the smallest (P < 0.05). Force to break the shell was lowest (P < 0.05) for Barred Plymouth Rock (3.6 kg) and greatest for the commercial (4.4 kg), White Leghorn (4.4 kg), and Fayoumi (4.2 kg). Bacteria penetrating the shell was lowest (P < 0.05) for Barred Plymouth Rock (10.7 cfu/g) and highest for Light Sussex (27.7 cfu/g) and Brown Leghorn (27.2 cfu/g), with other breeds intermediate. These results indicate that there are breed-specific influences on the ability of an egg to resist Salmonella, which cannot be explained by shell quality measurements. Further investigations are warranted to determine the contributing factors to shell penetration by bacteria. This study highlights the value in maintaining heritage chicken breeds as a genetic resource for the future.

The Influence of Personality on a Group‐Level Process: Shy Hermit Crabs Make Longer Vacancy Chains

AbstractAnimal personality has been investigated in a variety of contexts but few studies have investigated the effects of individual‐level traits on processes that occur at the group or population level. Vacancy chains describe sequences of linked vacancy moves in systems where individuals use discrete and reuseable resource units. When a new resource unit becomes available, this can cause a cascade of moves between resource units, beyond the first individual that encounters the new unit. Thus, vacancy chains can drive the distribution of resources through a population. Here, I investigate the effect of variation in boldness on movements between vacant gastropod shells in the hermit crab Pagurus bernhardus. Boldness was quantified using the duration of a startle response, which varied consistently between individuals. In groups of five crabs, introduction of a single new shell led to aggregate benefits, in terms of improving shell quality, across all group members. Boldness did not influence the extent of these benefits or the extent to which they were distributed between crabs of different sizes. Initially, vacancy chains were longer, indicating that more individuals moved between shells, for bold groups compared with shy groups. After 24 h, however, the chain length was longer for shy groups. Thus, although participation in a vacancy chain may lead to similar benefits, these could be more widespread for groups comprising shy individuals that show long startle responses, low inquisitiveness and low aggression. Similar effects on resource acquisition could be present in other examples of animals that utilise reusable resource units and show consistent between‐individual differences in behaviour.

Effects of Formic Acid Administration in the Drinking Water on Production Performance, Egg Quality and Immune System in Layers during hot Season

The objective of this study was to determine the effects of formic acid on egg production, egg weight, feed conversion ratio, egg quality and immunity in commercial layer reared during the hot season. In this study, 360 Hy-Line W-98 commercial White Leghorn, 68-week old hens were randomly assigned into four groups. The first group (control) continued receiving normal drinking water and other three groups consumed drinking water containing formic acid at levels of 0.5, 1.0 and 1.5 mL L−1. The results showed that the laying hens that consumed drinking water with formic acid had greater egg production, egg weight and egg mass than the control. Similarly, feed conversion improved with the administration of formic acid in water. Haugh units, egg shell thickness and egg grading from hens consuming acidified water containing 1.0 or 1.5 mL L−1 were significantly greater than those from the control group. Formic acid had no effect on yolk colour. In addition, the geometric means HI titres against Newcastle disease of birds consuming water containing formic acid were higher on all sampling days than those consuming water without acid. This study showed that formic acid at levels of 1.0 or 1.5 mL L−1 positively influences egg production, egg weight, shell quality, egg grading and enhances the immunity in older commercial layers during the hot season.

Key synthesis parameters on preparation of PS@Au nanoshells with chitosan polyelectrolyte

An experimental study is presented of the effect of key processing parameters on the seed-and-grow synthesis of PS@Au nanoshells with chitosan as a surface modifier. The parameters of (1) different seeds, (2) pH of buffer solution, (3) reducing agents and (4) K-gold concentration were studied. The first two are related to the seeding phase whereas the latter two to the growth phase. Carboxylate-terminated polystyrene (PS) spheres were synthesized and then modified by chitosan. Gold seeds of 1–20nm were prepared and anchored at the PS surface via the NAu bonding for growth of a complete gold shell. Studies show that THPC-gold nanoparticles are favored for seed coverage, and the pH value of the solution is important for surface functionalization. While the reducing agents studied all produce complete Au nanoshells under their respective optimal conditions, the shell quality differs with different reducing agents. For robust synthesis of PS@gold nanoshells, the following conditions are recommended: the THPC-gold particles as seeds, pH of 2.5–3.0, formaldehyde as the reducing agent and a K-gold concentration of 2.5×10−4M. By fine-tuning these parameters, the nanoshells of desired thickness and smoothness can be made. These findings are supported by the TEM images of seed and shell morphologies and by the measured UV–vis spectra of light absorption.

Egg Morphometry and Eggshell Quality in Ring-Necked Pheasants Kept in Cages / Budowa jaja i jakość skorupy u bażantów obrożnych utrzymywanych w klatkach

Abstract The aim of the study was to evaluate the morphometry and shell quality of eggs laid by pheasants kept in cages, and also to analyse the dependence between egg shell colour parameters, its quality and morphometric characteristics. Four groups of 15 eggs (60 eggs), each classified according to their eggshell colours, i.e. blue, light brown, dark brown and olive, were examined. The eggs did not differ significantly between each other in their mean weight and olive-coloured eggs had a higher shape index (about 8.91 percentage points) than blue eggs. Blue and light brown coloured eggs had thinner shells than the dark brown eggs (by 33.57 and 27.97 μm, respectively). Blue eggs had the lightest shells (L* = 67.97) and the highest proportion of green colour in their shells since the a* parameter value for blue eggs was negative. A significant positive correlation was observed between the egg shape and the shell colour saturation (C*) and the proportion of yellow colour (b*) in it. In addition, a negative correlation was found between lightness in eggshell colour, its thickness and the egg shape (r = from -0.338* to -0.480**). In comparison with the data obtained from the literature concerning the quality of eggs laid by pheasants kept in aviaries and eggs laid by birds kept in cages, the eggs were described as having similar weights and morphometries along with greater shell thicknesses. Furthermore, our study confirmed that pheasant eggs with blue and light brown colour have poorer shell quality, a fact which has been shown already in earlier research. However, this fact is related to the lightness of the shell pigment rather than its colour.

The Microstructure of Egg Shell Waste Treated with H3PO4, In vitro Solubility in Different Particle Size and the Using Effect on the Egg Shell Quality of Laying Hens

The Microstructure of Egg Shell Waste Treated with H3PO4, In vitro Solubility in Different Particle Size and the Using Effect on the Egg Shell Quality of Laying Hens

Effects of egg shell quality and washing on Salmonella Infantis penetration

The vast majority of eggs in Australia are washed prior to packing to remove dirt and fecal material and to reduce the microbial contamination of the egg shell. The egg contents can be an ideal growth medium for microorganisms which can result in human illness if eggs are stored improperly and eaten raw or undercooked, and it is estimated that egg-related salmonellosis is costing Australia $44million per year. Egg shell characteristics such as shell thickness, amount of cuticle present, and thickness of individual egg shell layers can affect the ease with which bacteria can penetrate the egg shell and washing could partially or completely remove the cuticle layer. The current study was conducted to investigate the effects of egg washing on cuticle cover and effects of egg shell quality and cuticle cover on Salmonella Infantis penetration of the egg shell. A higher incidence of unfavorable ultrastructural variables of the mammillary layer such as late fusion, type B bodies, type A bodies, poor cap quality, alignment, depression, erosion and cubics were recorded in Salmonella penetrated areas of egg shells. The influence of egg washing on the ability of Salmonella Infantis on the egg shell surface to enter the egg internal contents was also investigated using culture-based agar egg penetration and real-time qPCR based experiments. The results from the current study indicate that washing affected cuticle cover. There were no significant differences in Salmonella Infantis penetration of washed or unwashed eggs. Egg shell translucency may have effects on Salmonella Infantis penetration of the egg shell. The qPCR assay was more sensitive for detection of Salmonella Infantis from egg shell wash and internal contents than traditional microbiological methods. The agar egg and whole egg inoculation experiments indicated that Salmonella Infantis penetrated the egg shells. Egg washing not only can be highly effective at removing Salmonella Infantis from the egg shell surface, but also allows subsequent trans-shell and trans-membrane penetration into the egg. Consequently, it is important to prevent recontamination of the egg after washing.

EFFICACY OF TYLOSIN TARTRATE ON &lt;i&gt;MYCOPLASMA&lt;/i&gt; INFECTIONS AND EGGSHELL APEX ABNORMALITIES IN LAYER HENS UNDER FIELD CONDITIONS

The aim of this report was to describe a clinical case of concurrent infection with Mycoplasma Gallisepticum (MG) and Mycoplasma Synoviae (MS) in layers, complicated with Escherichia coli and Pasteurella multocida, as well as to evaluate the efficacy of tylosin tartrate treatment (Pharmasin® 100% WSG, Huvepharma) on Mycoplasma under field conditions. A flock of 18,500 ISA Brown pullets, 21 weeks of age and MS positive, showed an increase in weekly mortality, with no influence on egg production. At 24 weeks of age, post mortem was carried out and blood samples were collected, as well as samples for microbiological cultures from the lesions. In necropsy, several findings of pericarditis, airsacculitis of posterior thoracic sacs, prolapse and egg yolk peritonitis were found. Sporadic neurological signs were also apparent and post mortem examination revealed yellow caseous exudate accumulations in cranial bones. Although egg production was not influenced, Eggshell Apex Abnormalities (EAA) were increased with a significant number of both broken and misshapen eggs together with discoloration. Elisa serological examinations for Infectious Bronchitis Virus (IBV) and Newcastle Disease Virus (NDV) were within vaccination program limits, but MS, MG and Avian Rhinotracheitis (ART) results showed a significant seroconversion. Microbiology also revealed the presence of Escherichia coli and Pasteurella multocida. On week 25, a drug treatment with tylosin tartrate was applied at a dose of 105 mg kg-1 body weight in drinking water for five consecutive days. Three days after treatment, misshapen, broken and discolored eggs were decreased. The mortality was also significantly decreased within a week since the beginning of tylosin administration and at 30 weeks of age was within acceptable levels. Post mortem evaluation confirmed the absence of previously gross lesions in primary organs. In summary, tylosin treatment in complicated Mycoplasma spp. infections under field conditions improved egg shell quality and decreased mortality, thus the economic losses linked to decreased egg production and labor costs were reduced.