Eggshell Quality Research Articles

Vaccine to fibroblast growth factor 23 peptides increases eggshell strength

Strategies that would increase eggshell quality could be of considerable value to egg producers. This research demonstrated the effective use of fibroblast growth factor 23 (FGF-23) peptide vaccines to increase eggshell quality of Single Comb White Leghorn laying hens (from 69 to 72 wk of age). Hens, fed a standard diet (containing 900IU/kg vitamin D3), were intramuscularly injected (and boosted) with either a control vaccine (n = 14 hens) or one of 2 FGF-23 peptide vaccines (peptides NP1, GMNPPPYS; and NP7, YTSTERNSFH; n = 15 hens for each peptide). During peak antibody titer, eggs were collected for shell and internal quality analysis, hens were artificially inseminated, and the hatchability of fertilized eggs was determined. Laying hens vaccinated with either FGF-23 peptide NP1 or NP7 had increased (P < 0.05) plasma phosphate level (mmol/L; NP1 = 1.74, NP7 = 1.76, control = 1.47), egg specific gravity (NP1 = 1.083, NP7 = 1.083, control = 1.079), and eggshell strength (g of force; NP1 = 4002, NP7 = 4157, control = 3102) when compared to control vaccinated hens. FGF-23 peptide NP1 vaccinated hens also had increased eggshell thickness (mm, P < 0.001), shell weight (g, P = 0.032), and shell index (% of whole egg, P = 0.023) when compared to control vaccinated hens. FGF-23 peptide NP7 vaccinated hens tended to have decreased eggshell weight (P = 0.064) when compared to control vaccinated hens. Hatchability of fertilized eggs was not affected in incubations 1 and 3, but tended to be decreased (P = 0.097) by FGF-23 peptide NP1 vaccination in incubation 2. In conclusion, vaccines to FGF-23 peptides increased eggshell quality of laying hens with minimal adverse effects on egg internal quality. The effect of FGF-23 peptide vaccination on hatchability remains to be clarified.

The effects of formic acid-treated shrimp meal on laying performance and egg quality in aged laying hens

An experiment was carried out to measure the suitability of using formic acid-treated shrimp meal (TSM) as a protein source for aged laying hens. Shrimp meal (SM), air-dried shrimp waste was treated with 3% formic acid (w/v) at room temperature for 20 min, sun-dried, ground to pass through 1.0 mm mesh screen and then ready to use as the TSM. A total of 56 Single Comb White Leghorn hens, 85 wk of age, were placed in individual cages and assigned randomly into 7 dietary groups of 8 birds each. A control diet, diets containing 5, 10, and 15% SM and diets containing 5, 10, and 15% TSM were prepared. Diets and water were given ad libitum during the 30-d experimental period. Hen-day egg production, egg mass, feed intake, and feed conversion ratio (FCR) were deteriorated with increasing levels of the SM in the diets (P < 0.05). In contrast, these parameters were unchanged with increasing levels of the TSM in diets and compatible with the control group. No significant improvements were observed in exterior or interior egg quality among the dietary groups, except for eggshell weight, strength and yolk color, which were significantly increased in SM and TSM groups when compared to the values in control group (P < 0.05). It is concluded that inclusion of TSM up to 15% in laying hen diets may have beneficial effects on laying performance along with improved eggshell quality and yolk color, and suggested that TSM is a promising combined source of protein and calcium in aged laying hens.

Effects of dietary supplementation of arginine-silicate-inositol complex on absorption and metabolism of calcium of laying hens.

The effects of supplementation of arginine-silicate-inositol complex (ASI; 49.5–8.2–25 g/kg, respectively) to laying hens were investigated with respect to eggshell quality, calcium (Ca) balance, and expression of duodenal proteins related to Ca metabolism (calbindin and tight junction proteins). A total of 360 laying hens, 25 weeks old, were divided into 3 groups consisting of 6 replicate of cages, 20 birds per cage. The groups were fed a basal diet and the basal diet supplemented with 500 or 1000 mg ASI complex per kilogram for 90 days. Data were analyzed by ANCOVA using data during the first week of the adaptation period as covariates. As the ASI complex supplementation level increased, there were increases in feed intake (P < 0.0001), egg production (P < 0.001), egg weight (P < 0.0001) and eggshell weight (P < 0.001) weight, and shell thickness (P < 0.001) and decreases in feed conversion ratio and cracked egg percentage (P < 0.0001 for both). Concentrations of serum osteocalcin (P < 0.0001), vitamin D (P < 0.0001), calcium (P < 0.001), phosphorus (P < 0.001), and alkaline phosphatase (P < 0.008) as well as amounts of calcium retention (P < 0.0001) and eggshell calcium deposition (P < 0.001), and Ca balance (P < 0.0001) increased, whereas amount of calcium excretion (P < 0.001) decreased linearly in a dose-dependent manner. The ASI complex supplementation increased expressions of calcium transporters (calbindin-D28k, N sodium-calcium exchanger, plasma membrane calcium ATPase, and vitamin D receptor) and tight junction proteins (zonula occludens-1 and occludin) in the duodenum in a linear fashion (P < 0.0001 for all). In conclusion, provision of dietary ASI complex to laying hens during the peak laying period improved eggshell quality through improving calcium utilization as reflected by upregulation of genes related to the calcium metabolism. Further studies are needed to elucidate the contribution of each of the ASI complex ingredients.

Effect of housing system and age of laying hens on eggshell quality, microbial contamination, and penetration of microorganisms into eggs

Hens of the laying hybrid ISA Brown were used in the study with the objective to evaluate eggshell quality, microbial contamination of eggshells, and penetration of microorganisms into the egg content in different housing systems (enriched cage: 60 hens, 10 hens per cage, 750 cm&lt;sup&gt;2 &lt;/sup&gt;per hen vs free range: 60 hens, 9 hens per m&lt;sup&gt;2&lt;/sup&gt;) and at different hen ages (26 vs 51 weeks) during storage time (0, 2, 7, 14, and 21 days). A significant interaction between the housing system and age was observed in egg weight and most of eggshell quality measurements. However, microbial contamination and penetration were affected mostly by the housing system and storage time. The numbers of Escherichia coli (P &amp;lt; 0.001, 4.51 vs 2.75 log cfu/eggshell) and Enterococcus (P &amp;lt; 0.001, 2.56 vs 1.11 log cfu/eggshell), and the total number of microorganisms (P &amp;lt; 0.001, 5.04 vs. 3.65 log cfu/eggshell) were higher in free range eggs compared to enriched cage eggs, respectively. The counts of Escherichia coli (P &amp;lt; 0.001, 4.23 vs 2.91 log cfu/eggshell) and Enterococcus (P &amp;lt; 0.001, 2.31 vs 1.27 log cfu/eggshell) decreased with storage time. A positive correlation between the total number of pores and penetration of Escherichia coli in both housing systems was observed in the albumen. It can be concluded that the housing system and age of laying hens significantly affected eggshell quality. Microbial contamination presumably affects the penetration of microorganisms. The correlation between the number of pores and penetration is assumed to be affected by the microbial species.

Effects of carbohydrase enzyme supplementation on performance, eggshell quality, and bone parameters of laying hens fed on maize- and wheat-based diets

ABSTRACT1. This study was conducted to determine the effects of enzyme supplementation of maize/wheat-based diets on the performance, egg quality, and serum and bone parameters of laying hens.2. During the 12-week experimental period, a total of 72 laying hens aged 52 weeks were randomly distributed among 6 experimental groups. Each experimental group contained 4 replicates, each with three birds. The experiment was a randomised design consisting of a 3 × 2 factorial arrangement, with three levels of wheat substitution and two levels of enzyme (xylanase: 1500.00 U/kg, β-glucanase: 100 000 U/kg, cellulase: 1 000 000 U/kg, α-amylase: 160 000 U/kg) inclusion in the diet. Wheat replaced 0, 50, or 100% of maize with or without 1.0 g/kg enzyme supplementation in iso-nitrogenous and iso-caloric experimental diets.3. Body weight, egg production, egg weight, egg mass, eggshell thickness, and the feed conversion ratio were adversely affected by the wheat-based diet. The eggshell quality parameters decreased with enzyme supplementation to the diet.4. Wheat-based diets adversely affected calcium and phosphorus concentrations in the tibia, but the addition of the enzymes to the wheat-based diet prevented the negative effects of wheat-based diets on tibia mineralisation in laying hens. The wheat-based diets tended to reduce plasma mineral contents, and the addition of enzymes tended to affect plasma minerals and biomechanical properties of the tibia positively in laying hens.5. These results indicate that wheat-based diets in aged laying hens adversely affected the mineral metabolism compared with maize-based diets, and the negative effects of wheat on bone mineralisation can be prevented by enzyme supplementation to the diets in laying hens.

Effects of dietary probiotic (Bacillus subtilis) supplementation on productive performance, immune response and egg quality characteristics in laying hens under high ambient temperature

A two level factorial experiment (3 × 3) was designed to evaluate the effect of dietary inclusion level of probiotic and breed on productive performance, immune status and egg quality characteristics in laying hens reared under high ambient temperature. A total of 216, 32-week-old laying hens representing three different breeds (White Leghorn, Saudi black and Saudi brown) were randomly assigned to three dietary treatments (0, 200 and 400 g/t feed) in a 90-d experiment. The current results indicated that the inclusion of probiotics in layer diets did not appear to cause any adverse effects on egg production traits compared with non-treated hens. Dietary supplementation with probiotics at 400 ppm level significantly (p < .05) increased shell thickness compared to non-treated laying hens. Moreover, an improvement in eggshell quality and breaking strength in hens fed a diet containing probiotics was observed under high ambient temperature. Also, plasma cholesterol and triglyceride were reduced in laying hens fed a diet supplemented with probiotics. Furthermore, probiotic inclusion significantly increased IgM immunoglobulin concentration in laying hens fed a diet containing either 200 or 400 ppm compared with untreated hens. Concerning breed effect, Saudi black laying hens recorded significantly (p < .02) higher egg mass compared with the other breeds. Also, both Saudi chicken breeds exhibited significantly higher cell-mediated response and IgM concentration compared with Leghorn hens.

Influence of homeopathic medicines and feeding regimen on egg shell quality of layers in hot and humid summer

An experiment was conducted to study the effect of six dietary manipulations in fish meal and corn soya based diet on the egg shell quality of white leghorn hens (WLH) during hot and humid summer. A total of ninety six WLH were divided among 12 dietary treatment groups with 8 birds per treatment. The birds were housed in individual cages for an experimental period of 30 days. Following a 2x6 factorial design six dietary manipulations viz. 1) early (5: 00 am) morning feeding, 2) Calcarea carbonica (Calc carb®), 3) Kalium phosphoricum (Kali phos®), 4) control 5) 0.1% NaHCO3, and 6) 0.3% Methionine hydroxy analogue free acid (MHA-FA) were employed in each fish meal (FM) based and corn-soya (CS) based diet to form 12 dietary treatments. The results have revealed that Kali phos® and Calc carb® were helpful in improving egg shell quality. The former resulted in better egg shell quality in FM based diet. The sodium bi-carbonate, MHA-FA, and early-morning-feeding resulted in significant improvement compared to control in parameters pertinent to egg shell quality. The FM based ration resulted in better egg shell quality compared to CS (Corn-Soya) based ration. Therefore, based on the results of the present study the homeopathic medicine viz. Kali phos® and or Calc carb® in fish meal based diet are a good choice for layer birds to control the loss due to poor shell quality during hot and humid summer.

Effect of selected feed additives on egg performance and eggshell quality in laying hens fed a diet with standard or decreased calcium content

Abstract The aim of the experiment with 240 ISA Brown hens fed the diets with standard or decreased Ca level was to evaluate the effect of selected feed additives on laying performance and eggshell quality. The hens were allocated to 10 treatments, each containing 12 cages (replicates) of 2 birds. A 2 × 5 experimental arrangement was used. From 26 to 70 wks of age, experimental diets containing 3.20 or 3.70% Ca were used. The diets were either not supplemented, or supplemented with sodium butyrate, probiotic bacteria, herb extracts blend or chitosan. The decreased dietary Ca reduced eggshell quality indices in older hens (43-69 wks) (P&lt;0.05) without effect on performance indices. The addition of the probiotic, herb extracts, or chitosan increased the laying rate (P&lt;0.05). In older hens, i.e. at 69 wk, chitosan increased eggshell thickness and breaking strength, while herb extracts increased eggshell thickness (P&lt;0.05). There was no interaction between the experimental factors in performance and eggshell quality. The used feed additives had no influence on fatty acid profile of egg lipids, however diet supplementation with chitosan decreased cholesterol concentration in egg yolk lipids (P&lt;0.05). It can be concluded that such feed additives as probiotic, herb extracts, or chitosan may positively affect performance and eggshell quality, irrespective of Ca dietary level.

Exploratory study on characteristics of oyster shell and eggshell quality in Chile

This study aimed to characterise oyster shell and white egg shell quality in Chile. The work was based on samples of both oyster shell and eggs, which were sourced from 7 laying farms over a period of several weeks during the production stage. Oyster shells were characterised according to their calcium content and granulometric distribution, and were classified in three types of particles (mm): coarse (≥1.7), medium-sized (0.9-1.6) and fine (≤0.8). Eggs were characterised, according to hen age and farm, by determining their weight, eggshell resistance, and thickness. Currently, Chilean farms use oyster shells whose calcium content ranges from 32.5% to 34.8%, and their granulometric distribution is 51.7% coarse, 27.6% medium-sized and 18.1% fine particles. Thus, the predominant form of oyster shell traded by major companies in Chile is the coarse type of particles, followed by medium-sized and fine particles. Similar calcium contents were observed for oyster shell samples sourced from different farms. Similar weight of the eggs were found for all farms (60-64 g). Contrarily, farms presented different results for eggshell resistance (3,934-5,057 g) and eggshell thickness (0.322-0.376 mm). Eggshell resistance and thickness values were within the expected range for white hen eggs. Key words : calcium, eggs, granulometry, oyster shell.

Climate Variability, Incidences and Mitigation Strategies among Poultry Farmers in Abia State, Nigeria

This paper investigated climate variability, incidences and mitigation strategies among poultry farmers in Abia State, Nigeria. It specifically analysed the trend of climate variables over the period of 30 years, the perception of poultry farmers as regards the impact of climate variability on poultry production in the study area, and examined the different mitigation strategies adopted by these farmers. A multi-stage sampling technique was employed in choosing the required sample of 120 poultry farmers. Data were collected with validated structured questionnaire, and analyzed using descriptive statistics. The result showed a high inter-annual variability in the volume of rainfall from 1983 to 2012 with insignificant correlation (0.0781) between rainfall volume and time. Also, the result showed reduction in number of rainy days and sunshine duration between 1983 and 2012 with correlation coefficients of 0.146 and 0.132respectively. Temperature had significant positive relationship with time with correlation coefficient 0.638.High mortality rate, disease outbreak, smallness of egg size, poor quality of egg shell, heat stress and reduced feed intake actually impacted on poultry production in the study area. Climate variability was therefore found to have affected poultry production in the study area and this has serious environmental and food policies implication. The respondents identified the use of climate resilient breeds, closeness to hatchery, feed improvement, mixed farming, use of artificial cooling system and stocking less during harsh season as major mitigation strategies to climate variability. It is therefore recommended that the government should come up with appropriate policy that will assist the poultry farmer to be more resilient and able to cope with effect of climate variability. Policies should also be formulated to reduce the emission and accumulation of green-house gases in our environment.

The Influence of Phytase Enzyme to Laying Performance and Quality of Egg Shell of Golden Arabian Chicken

Poultry has low ability to digest dietary fibre and to process phytate. Rice bran is intensively used in poultry ration although it contains little bit higher in fibre and phytate. The purpose of this study was to find out the optimal level of phytase the enzyme that could break down phytate in the ration of Golden Arabian chicken to increase performance and physical quality of the eggs. This study used 90 golden arabian chickens (Golden Brakel Kriel), approximately five months of age. Individual cage with a wire floor was equipped with a feed and drinking troughs. Experimental ration was with a mixture of corn, rice bran, commercial concentrate, and mineral mixture. Phytase was added at the level of: zerro, without phytase = P1; 100 FTU/ kg of ration; 200 FTU/kgof ration = P2; 300 FTU/kg of ration =P3; 400 FTU/ kg of ration = P4; and 500 FTU/kg of ration = P5. Experimental design that used in this study was Complete Randomized Design (CRD) with six treatments and five replications and three golden arabian chickens per experimental unit. Results showed that the addition of phytase in golden arabian chickens ration improved the hen day production (P &lt;0.05) up to 71.43% and increased the physical quality, especially weight of eggshell significantly (P &lt;0.05) up to 4.516 gram (phytase enzyme 300 FTU/kg) . In conclusion, that the level of the phytase of 300 FTU/kg of ration was the most optimal dose to increase the daily egg production and improve the physical quality. However, the addition of phytase did not affect to feed consumption, feed efficiency, eggshell thickness and eggshell thickness index.

Eggshell characteristics and cuticle deposition in three laying hen genotypes housed in enriched cages and on litter

The objective of the present study was to compare the eggshell characteristics and cuticle deposition of Lohmann Brown, Hy-Line Silver Brown, and Isa Brown layers kept in two different housing systems. The three laying hen genotypes were housed in enriched cages (100 hens, 750 cm&lt;sup&gt;2&lt;/sup&gt;/hen, 10 hens/cage) and in littered pens (100 hens, 9 hens/m&lt;sup&gt;2&lt;/sup&gt;, 10 hens/pen). The experiment was carried out in weeks 40–56 of hens age. Non-significant interactions of genotype and housing system for eggshell quality parameters and cuticle deposition were detected in this study. Egg weight was significantly affected by genotype (P ≤ 0.001) and housing system (P ≤ 0.043). The heaviest eggs were laid by Lohmann Brown, while the lightest eggs were produced by Hy-Line Silver Brown. Eggshell strength was not affected by genotype and housing system, however, genotype had a significant effect on eggshell thickness (P ≤ 0.033). Isa Brown eggs had thicker eggshells compared to Lohmann Brown and Hy-Line Silver Brown. However, a non-significant effect of housing system on eggshell thickness was observed. Eggshell percentage was significantly affected by both genotype and housing system. Genotype of laying hens had a significant effect on cuticle deposition; significantly higher cuticle deposition was observed in Lohmann Brown eggs (P ≤ 0.001). It could be concluded that genotype had a significant effect on eggshell quality parameters and cuticle deposition. However, the housing system effect was less important in these characteristics.

Effect of Diets with Various Calcium and Boron Levels in Prelaying Period on Growth, Bone Ash and Subsequent Performance and Shell Quality of Laying Hens

This experiment was conducted to determine the effects of diets with three different levels of calcium (% 0.8, 1.6, 3.2) and four different levels of boron (0, 75, 150, 300 mg kg-1) in prelaying period (14-20 weeks) on growth, bone ash and subsequent performance and egg shell quality of laying hens. A total 864 Super Nick pullets at 14 weeks of age were randomly allocated to twelve treatments arranged in a 3x4 factorial design with six replicates of 12 pullets each. Feed and water provided for ad-libitum access. The tibia samples were taken, three pullets and hens from every replicates at 20 and 42 weeks of age, respectively. Results of the present experiment showed that body weights and body weight gains were reduced in high prelay dietary Ca and B as the main factor. Feed intake of the pullets was not significantly influenced by the treatments. There were no detectable difference in feed intake, egg production, egg mass and feed conversion ratio (g, feed/ g, egg mass) and eggshell weight, but interactive effects of dietary Ca and B levels on eggshell thickness, egg specific gravity and shell breaking strength was significant. Shell thickness and breaking strength were significantly higher in hens fed pre-lay diet with 3.2 % Ca and no supplemental B than other treatments and egg specific gravity was significantly reduced by feeding 1.6 % Ca and 75 mg kg-1 B at 36 weeks of age. Bone ash (g or %) of hens at 20 and 42 weeks of age was not changed by Ca levels or interaction dietary Ca and B levels, but pullets receiving the 150 mg kg-1 B as the main factor had significantly higher in bone ash (g or %) values than other dietary B levels.

Calcium Intake Level as Factor of Influencing of the Eggshell Qualities in Laying Hens

The experiments were carried out on four groups of Hy-Line var. Brown hens (n = 350 each) monitored from 20 to 68 weeks of age. The hens were fed on diets which provided the following calcium intakes (%): 2.56 and 3.12 in groups I and II, respectively, 3.86 in control and 4.22 in group III. The shell weight increased during the laying period proportionally to the ingested calcium. The thickness of the eggshell decreased: the decrease was higher in the groups which ingested less calcium. The eggshell strength increased from 20 to 36 weeks of age in all the hen groups. Further, the eggshell strength decreased from 36 to 68 weeks of age. These decreases were higher as the amount of calcium intake increased. In conclusion, calcium diet influences on eggshell properties are age-dependent and more pronounced at the peak of laying period. The increase in diet calcium content from 3.86 to 4.22% has less and negative influences on the physical properties of the eggshell.

Efficacy of dietary phytase supplementation on laying performance and expression of osteopontin and calbindin genes in eggshell gland.

This study was conducted to evaluate the effects of different levels of dietary phytase supplementation in the layer feed on egg production performance, egg shell quality and expression of osteopontin (OPN) and calbindin (CALB1) genes. Seventy-five White Leghorn layers at 23 weeks of age were randomly divided into 5 groups consisting of a control diet with 0.33% non-phytate phosphorus (NPP) and 4 low phosphorus (P) diets: 2 diets (T1 and T2) with 0.24% NPP + 250 FTU/kg laboratory produced phytase or commercial phytase and another 2 diets (T3 and T4) with 0.16% NPP + 500 FTU/kg laboratory produced phytase or commercial phytase with complete replacement of inorganic P. The results indicated that there were no significant differences (P > 0.05) in egg production performance and quality of egg during the first 2 months of trial. However, in next 2 months, a significant drop in egg production and feed intake was observed in birds fed diets with low P and 500 FTU/kg supplementation of laboratory produced phytase. Osteopontin gene was up-regulated whereas the CALB1 gene was down regulated in all phytase treatment groups irrespective of the source of phytase. The current data demonstrated that 250 FTU/kg supplementation of laboratory produced phytase with 50% less NPP supplementation and 500 FTU/kg supplementation of commercial phytase even without NPP in diet can maintain the egg production. The up-regulation of OPN and down regulation of CALB1 in egg shell gland in the entire phytase treated group birds irrespective of the source of enzymes is indicative of the changes in P bio-availability at this site.

Effect of different split-feeding treatments on performance, egg quality, and bone quality of individually housed aged laying hens.

In order to try to combat the effect of age on eggshell quality in aged laying hens, 5 split-feeding treatments were compared with conventional feeding between 75 and 92 wk of age. In the conventional treatment (T1), the same morning (M) and afternoon (A) diet was fed containing fine (FL) and coarse (CL) limestone at a 50:50 ratio. In the split treatments, the ratio of FL and CL was 50:50 or 30:70, and time of administration (M/A) differed. The following treatments were given: T2 = 50FL-M:50CL-A, T3 = 50CL-M:50FL-A, T4 = 30FL-M:20FL-A+50CL-A, T5 = 30FL-M:70CL-A, and T6 = 0M:30FL-A+70CL-A. A total of 12 individually housed Dekalb white hens was used per treatment. Feed intake, nutrient intake, and laying % was lower in T1 compared to all split treatments (P≤0.001). Due to this low performance in T1, split feeding could not be compared to the conventional system in this trial. By the end of the trial, eggshell quality was improved in T1 as a result of low laying % and more frequent and longer laying pauses. In the split treatments, laying % and feed intake were similar, except in T3 in which a decrease was observed after 81 wk (P≤0.05). Egg weight was higher in T5 and T6 due to higher total and morning protein intake compared to T3 (P≤0.05). Feeding only 50FL-A in T3 not only resulted in lower performance but also in consistently lower shell thickness, indicating a negative effect of suboptimal limestone supplementation. In the split-feeding system, the most optimal combination of morning and afternoon diet was a morning diet with only FL and an afternoon diet with only CL (T2), which both provided ∼50% of the total daily Ca intake. Shell breaking strength and dynamic stiffness could be maintained on this diet between 75 and 92 weeks. Decreasing the amount of Ca in the morning and increasing it in the afternoon did not improve shell quality traits. Bone quality was not affected by limestone particle size or inclusion level in the split-feeding system.

Synergetic effects of essential oils mixture improved egg quality traits, oxidative stability and liver health indices in laying hens fed fish oil

Omega-3 fatty acids are necessary for human health, although products containing higher proportions of these fatty acids make them more susceptible to lipid peroxidation. The current study was conducted to evaluate the synergetic effects of dietary supplementation of herbal essential oils mixture (Thymus vulgaris, Mentha piperita, Rosmarinus officinalis and Anethum graveolens) and dietary fat sources on egg quality traits, oxidative stability and liver health indices of laying hens. A total of 150 laying hens were randomly distributed among 6 experimental treatments with five replicates of five birds each. Dietary treatment consisted of three levels of herbal essential oils mixture (0, 100 and 200mg/kg) and two sources of fat (fish oil and soybean oil containing different ratios of n-6 to n-3 fatty acids) that fed during an 80 d feeding trial. The results showed that administrating fish oil, containing low ratio of n-6 to n-3 fatty acids, enhanced liver (P<0.05) malondialdehyde concentration, egg yolk color (P<0.05), and led to the reductions in liver relative weight, hepatic lipid percentage (P<0.05), serum alkaline phosphatase activity (P<0.01), as well as serum and egg yolk cholesterol contents (P<0.05). Moreover, herbal essential oils mixture resulted in the declines in blood cholesterol and triglyceride concentrations (P<0.01), enzymes activity of alanine aminotransferase and aspartate aminotransferase (P<0.01), as well as hepatic and serum malondialdehyde concentrations (P<0.05). Also, it caused the improvements in eggshell hardness and thickness (P<0.05). In general, the findings indicated that although dietary administration of fish oil increased the susceptibility of serum and liver to lipid peroxidation, feeding 200mg/kg essential oils mixture resulted in the best systemic and hepatic antioxidant responses, the modulated serum lipid profiles, and also the improved eggshell quality.

Susceptibility to keel bone fractures in laying hens and the role of genetic variation

Keel bone fractures are a well-known welfare problem in modern commercial laying hen systems. The present study sought to identify genetic variation in relation to keel bone fracture susceptibility of 4 distinct crossbred and one pure line, and by extension, possible breeding traits. Susceptibility to fractures were assessed using an ex vivo impact testing protocol in combination with a study design that minimized environmental variation to focus on genetic differences. The 5 crossbred/pure lines differed in their susceptibility to keel bone fractures with the greatest likelihood of fracture in one of the 3 commercial lines and the lowest susceptibility to fractures in one of the experimental lines. Egg production at the hen-level did not differ between the crossbred/pure lines (P >0.05), though an increased susceptibility to keel bone fractures was associated with thinner eggshells and reduced egg breaking strength, a pattern consistent among all tested crossbred/pure lines. Our findings suggest an association between egg quality and bone strength which appeared to be independent of crossbred/pure line. The findings indicate the benefit of the impact methodology to identify potential breeding characteristics to reduce incidence of keel fracture as well as the potential relationship with eggshell quality.

Characteristics of global organic matrix in normal and pimpled chicken eggshells

The organic matrix from normal and pimpled calcified chicken eggshells were dissociated into acid-insoluble, water-insoluble, and facultative-soluble (both acid- and water-soluble) components, to understand the influence of shell matrix on eggshell qualities. A linear correlation was shown among these 3 matrix components in normal eggshells but was not observed in pimpled eggshells. In pimpled eggshells, the percentage contents of all 4 groups of matrix (the total matrix, acid-insoluble matrix, water-insoluble matrix, and facultative-soluble matrix) were significantly higher than that in normal eggshells. The amounts of both total matrix and acid-insoluble matrix in individual pimpled calcified shells were high, even though their weight was much lower than a normal eggshell. In both normal and pimpled eggshells, the calcified eggshell weight and shell thickness significantly and positively correlated with the amounts of all 4 groups of matrix in an individual calcified shell. In normal eggshells, the calcified shell thickness and shell breaking strength showed no significant correlations with the percentage contents of all 4 groups of matrix. In normal eggshells, only the shell membrane weight significantly correlated with the constituent ratios of both acid-insoluble matrix and facultative-soluble matrix in the whole matrix. In pimpled eggshells, 3 variables (calcified shell weight, shell thickness, and breaking strength) were significantly correlated with the constituent proportions of both acid-insoluble matrix and facultative-matrix. This study suggests that mechanical properties of normal eggshells may not linearly depend on the organic matrix content in the calcified eggshells and that pimpled eggshells might result by the disequilibrium enrichment of some proteins with negative effects.

Age influence on quality of shell and penetration in bacterial laying lightweight eggs

ABSTRACT This study evaluated the influence of the bird’s age on the quality of the shell and percentage of bacterial penetration in commercial eggs. White-shelled commercial eggs were used, laid by light laying hens in their first laying cycle at 21, 39, 51, and 62 weeks of age. Shell quality evaluations comprised: egg weight, specific gravity, percentage and thickness of shell, number and size of pores. For evaluations regarding bacterial penetration, strains of several enterobacterias and one salmonella were used, all of which resistant to Nalidixic acid (100µg/ml). The method employed for evaluation of bacterial penetration was filling the eggs with growth medium. The data were subjected to variance analysis with 5% of probability using SAS (Education Analytical Software, 2013). Eveb though increase in the laying hen's age caused reduction of the quality of eggshells, it failed to affect the percentage of penetration of the bacterial samples evaluated.