Eggshell Quality Research Articles

Effects of phytase supplementation on eggshell and bone quality, and phosphorus and calcium digestibility in laying hens from 25 to 37 wk of age

Effects of dietary available phosphorus (aP) and Ca levels and an Escherichia coli 6-phytase supplementation were studied in Lohmann LSL-Lite hens from 25 to 37 wk of age. Eighty-four hens were used in a completely randomized design with 7 treatments. The treatments were a positive control (PC) diet with 0.45% aP, 3.70% Ca, and 0.16% Na from 25 to 28 wk and 0.38% aP, 3.73% Ca, and 0.15% Na from 29 to 37 wk; a negative control (NC) diet, similar to the PC diet, with 0.22% aP, 3.00% Ca, and 0.13% Na from 25 to 28 wk and 0.19% aP, 3.02% Ca, and 0.13% Na from 29 to 37 wk; the NC diets supplemented with phytase at 150 (NC + 150), 300 (NC + 300), 600 (NC + 600), or 1,200 (NC + 1,200) phytase unit (FTU)/kg; and the PC diet supplemented with phytase at 1,200 (PC + 1,200) FTU/kg. Hen performance, eggshell, and bone quality were measured on a 4-wk basis. Bone breaking strength and ash and apparent ileal digestibility (AID) of P and Ca were determined at 37 wk. One- and 2-way ANOVA were conducted, and Tukey's range test was used to compare multiple means where P ≤ 0.05. No differences in hen performance, eggshell quality, bone breaking strength, bone ash, and P digestibility were observed between the PC and the NC treatments. The NC hens had lower cortical (P < 0.001) and trabecular + medullary bone mineral density (P = 0.004) and total bone mineral content (P < 0.001) than the PC hens. The PC + 1,200 increased cortical bone mineral density (P < 0.001). The reductions of aP and Ca in the NC diet were not deficient for performance but had a minor impact on bone mineralization. The NC + 600 and NC + 1,200 increased AID of P (P = 0.024), and all phytase treatments except the NC + 150 increased AID of Ca (P = 0.010) compared with the NC diet.

The effect of breed and age on the gloss of chicken eggshells

The monitoring of eggshell quality is important mainly in terms of production economy. Eggshell appearance is one of the most characteristics, influencing the purchasing behavior of consumers. Besides numerous eggshell appearance quality (color, shape, etc.), gloss is an important trait to reflect the eggshell appearance. In this study, 2 experiments were conducted to investigate the effect of breed and age on the gloss of eggshells. In experiment 1, we compared the eggshell gloss of 7 chicken breeds. In experiment 2, 105 Wanan (WA) chickens were raised, and 1 egg was collected from each individual at 26, 32, 40, and 50 wks of age. Eggshell gloss, color (L*, a*, b*), cuticle coverage (ΔE*ab), and thickness were measured. The results of experiment 1 showed that the average gloss values were highly variable among different breeds, and the highest was found in WA (gloss unit [GU] = 8.12), almost 2.5 folds as many as the lowest in Rhode Island Red (GU = 3.23). Also, the eggshell gloss of the local chicken breeds was significantly higher than the highly selected lines of egg-type chicken breeds (P < 0.001). In experiment 2, the results showed that gloss ranged from 9.08 GU to 12.12 GU with a variation of 28.38 to 39.71%. It fluctuated with the increasing age of hens and had the peak value at 26 wk. But, the correlation analysis between eggshell gloss and other eggshell quality traits were very low (−0.07 to 0.25). This study laid a foundation for improving the uniformity and intensity of eggshell gloss for breeders.

Performance, egg quality and resilience to nutritional challenges of Lohmann Dual hens as opposed to layer and traditional dual-purpose types: a preliminary study

Abstract Systems based on dual-purpose poultry present an alternative for avoiding the culling of male layer chicks. However, controlled comparisons on the production characteristics of dual-purpose poultry are lacking. A modern dual-purpose type (Lohmann Dual; LD) and two traditional dual-purpose types (Schweizerhuhn and Belgian Malines) were compared to a standard layer type (Lohmann Brown Plus; LB) from the start of lay until week 33 of lay. In 3- and 4-week periods, the resilience of the hens to nutritional challenges was investigated with split-plot crossover design. At first the supplementation of synthetic methionine was omitted. Later, the hens were confronted by a reduction of the content of N-corrected metabolisable energy from 11.5 to 10.5 MJ/kg feed. The laying percentage of LD was initially similar to that of LB, but persistency and egg size were inferior resulting in a daily egg mass of 46.6 vs. 58.5Â g in LB across the 33 weeks. Feed efficiency and egg quality of LD were in the range of LB. Laying percentage, egg size, feed efficiency and egg shell quality were poorer with the two traditional types. The omission of synthetic methionine and a reduction of 10% of the dietary content of metabolisable energy did not lead to a reduction in laying performance and egg quality in any hen type under the present conditions. Yet, stricter nutritional challenges imposed to minimise feed-food competition may turn to the advantage of modern and possibly traditional dual-purpose types, too.

EGG QUALITY OF SELECTED ACEH NATIVE CHICKENS FED ON THE DIETS COMPOSED OF Indigofera sp. MEAL BASED ON FEED FERMENTATION AS PARTLY SUBSTITUTION OF COMMERCIAL DIET

The objective of this study was to determine the effect of inclusion of fermented feed consisted of 15% Indigofera sp. + 40% rice bran + 25% corn bran + 20% soybean meal as partial substitution of commercial diet on the egg quality of selected Aceh native (SAN) chickens. As many as 48 SAN pullets were used in this study. The study was performed in a completely randomized design, consisted of 4 treatments and 4 replications. Each replication was an experimental unit consisted of three chickens. The results of study indicated that inclusion of up to 15% fermented feed which was composed of 15% Indigofera sp. + 40% rice bran + 25% corn bran + 20% soybean meal as substitution of commercial layer diet significantly (P0.01) improved yolk index without adverse effect on albumen and eggshell quality of SAN chickens. As conclution, substitution of fermented feed contained 15% indigofera may improve the egg quality of SAN chickens.

Genetic improvement of egg laying traits in Fayoumi chickens bred under conditions of heat stress through selection and gene expression studies.

Thermal stress has been shown to result in decreased egg production, decreased eggshell quality, and ultimately millions of dollars in losses to the industry. Therefore, there are many factors to consider when implementing genetic selection programs aimed at improving egg production under tropical conditions. So, trial is trying to improve the productivity and eggshell quality traits of the Fayoumi chicken under high ambient temperatures via selection programs and gene expression. In the present study, day-old Fayoumi chicks were raised either under normal temperature (control) or conditions of thermal stress (the heated group). At 35 weeks, male and female chickens from the control group were mated randomly and females selected for higher egg production and eggshell strength were mated to male siblings to obtain the progeny of the first generation (F1). F1 birds were further selected and mated to obtain the progeny of the second generation. Our results show that egg production and eggshell strength traits improved over successive generations via selection under conditions of heat stress. Furthermore, the reduction in egg production and eggshell strength as a result of heat stress declined from one generation to the next in birds selected for good heat tolerance, and an inverse relationship was observed between the OC-17 and eggshell strength. Additionally, levels of HSP90 and gene expression increased in the two successive generations, indicating that both productivity and heat tolerance were enhanced due to selection in birds raised under conditions of thermal stress. Moreover, generation exerted an important effect on this trait. Thus, desirable traits such as improved heat tolerance in producing lines were observed in Fayoumi chickens exposed to conditions of thermal stress via selection. Therefore, modern advances in studies of poultry breeding and genetics, such as gene expression studies, should be examined.

Rapid, non-destructive analysis of calcium and strontium in eggshells by WD-XRF

We developed a simple method of analyzing the strontium (Sr) and calcium (Ca) content of intact eggshell samples in support of a broader study of how dietary Sr uptake impacts waterfowl eggshell quality. We used wavelength dispersive - x-ray fluorescence spectrometry (WD-XRF) to analyze eggshell pieces ranging in size from ∼6-mm2 fragments to intact half-shells. We verified this approach on a subset of reference shells by subjecting the same region and volume of shell material from which x-ray signals were measured to analysis by inductively-coupled plasma mass spectrometry (ICP-MS). An analysis of the sources of analytical uncertainty yielded total internal error estimates of ±0.3 and 5% relative for Ca and Sr, respectively, on the basis of which the chemistry of intact shell material analyzed by WD-XRF in this study is compared. The total external errors associated with the WD-XRF results of this study in relation to certified reference material (National Institute of Standards and Technology [NIST] 1400 [a bone ash]) are ±9 and 13.5% relative for Ca and Sr, respectfully (95% CL). Our results demonstrate this method is acceptably accurate and precise for many wildlife management applications. WD-XRF analysis is a quick and inexpensive alternative to traditional methods for determining eggshell Sr and Ca that require acid digestion, allowing for generation of larger datasets that might otherwise be cost-prohibitive, while preserving sample material intact.

Classification of inhomogeneous eggshell-mottling patterns using a pretrained convolutional neural network

To determine eggshell quality, many external factors, such as appearance and cleanliness, can be detected by human graders. However, the inspection of the internal factor of strength of the eggshell has proven difficult. Some eggs develop hairline cracks due to low strength; this regularly happens in the process of egg production, causing economic loss and exposure to Salmonella contamination. These developed hairline cracks may be detectable. Although the effectiveness is in doubt, potential crack development of the eggshell can be predicted by observing the translucent mottling patterns of the eggshell. Early discarding of eggs with severe mottling has thus become a common practice in egg production to prevent further crack development and cross-contamination. However, accurately predicting potential crack development based on eggshell mottling is a challenge due to the irregularities of the mottling pattern itself, with difference in shape, size, distribution pattern, and color inhomogeneity. A pretrained convolutional neural network (CNN) model based on AlexNet architecture was proposed to extract learned image features of the mottling pattern on eggshells. The classification results by the fine-tuned CNN model was then compared to the classifications by the human graders as ground truthing. The fine-tuned CNN model performed on par to the human graders, with 91.8% similarity in classification rate. Visualization and analysis on intermediate activation strengths in the fine-tuned CNN model confirmed the consistency and traceability of the classification results. Our work underscores the potential of the CNN-based feature extraction and classification on eggs based on highly inhomogeneous mottling patterns on eggshell.

Dietary addition of zinc-methionine influenced eggshell quality by affecting calcium deposition in eggshell formation of laying hens - CORRIGENDUM.

Dietary addition of zinc-methionine influenced eggshell quality by affecting calcium deposition in eggshell formation of laying hens - CORRIGENDUM.

Effect of Dietary Zinc Level on Egg Production Performance and Eggshell Quality Characteristics in Laying Duck Breeders in Furnished Cage System

In order to investigate the effect of dietary Zn levels on laying performance, eggshell quality, and eggshell microstructure in Muscovy duck breeders under furnished cages. Firstly, the effects of age (35 weeks vs 40 weeks) and rearing system (littered floor vs furnished cage) on eggshell quality of laying duck breeders were studied (Exp. 1). Then, a total of 324 30-week-old Muscovy duck breeders were allotted into 3 dietary Zn groups with 6 replicates (18 ducks per replicate), including 0 mg Zn/kg (control-Zn group, C-Zn), 40 mg Zn/kg (normal-Zn group, N-Zn), and 140 mg Zn/kg (high-Zn group, H-Zn). The experimental period for 6 weeks was divided into 3 periods of 30-32, 32-34, and 34-36 weeks of age (Exp. 2). In Exp. 1, duck breeder eggs in the furnished cage system had lower the average shell thickness than birds in the littered floor system at 40 weeks of age (P < 0.05), not at 35 weeks of age. In Exp. 2, N-Zn and H-Zn groups had greater egg weight, egg production, and egg to feed ratio of duck breeders than C-Zn group (P < 0.05). Additionally, H-Zn group had higher laying rate, qualified egg ratio, and Haugh unit as well as lower mammillary cone width than C-Zn group (P < 0.05), with no differences between C-Zn and N-Zn groups (P > 0.05). Diet supplemented with 140 mg Zn/kg increased shell thickness and palisade layer thickness of duck breeders at 36 weeks of age (P < 0.05), but not at 32 and 34 weeks of age. In conclusion, diets with 40 or 140 mg Zn/kg improved egg production performance and egg quality of laying duck breeders during 30-36 weeks of age in a furnished cage system. Dietary supplementation of 140 mg Zn/kg level increased the ultrastructural palisade layer thickness contributing to greater eggshell thickness of duck breeders at 36 weeks of age.

Eggshell and Bone Quality in Two Different Genetic Groups of Aged Layer Breeders

ABSTRACT The present study was conducted on pair aged commercial laying breeder strains (Hy-Line Brown and Hy-Line W-36) to evaluate genetic differences of eggshell and bone quality. In addition, egg production performance, mortality rate, internal organs and reproductive measurements were determined. Correlation coefficients among some eggshell and bone traits were calculated. White layer breeder hens had significantly higher percentages of hen-day and hen-housed egg production compared to the brown one. Brown Hy-Line layer breeder strain had better eggshell quality compared to W-36 Hy-Line layer breeder strain. The white layer breeder strain had a significantly higher relative oviduct weight compared to the brown one. Brown layer breeder strain recorded the higher humerus width in comparison with the white one. Tibia bone weight of brown layer breeder strain was significantly heavier by 22.87% as compared to the white strain. Moreover, the brown breeder strain recorded the higher figure of tibia width, thickness, and strength. In conclusion, at the end of the laying cycle, brown Hy-Line layer breeder strain exhibited better eggshell quality, body weight and tibia bone quality than those of W-36 breeder strain. Positive correlation coefficients were detected between humerus bone strength and both eggshell thickness and strength in brown and white strains.

Association of three novel SNPs in the ATF4 gene with layer duck eggshell quality

Abstract Activating transcription factor 4 (ATF4) plays an important role in regulating the transport of calcium ions in the body. Therefore, we hypothesised that the ATF4 gene ( ATF4) affected poultry eggshell quality because calcium is the most important component of avian eggshells. The aim of this study was to explore the effects of single nucleotide polymorphisms (SNPs) of ATF4 on eggshell quality in laying ducks. The results indicated that three SNPs (g.149718392 GÂ >Â A, g.149718569 GÂ >Â A and g.149718665 AÂ >Â G) were identified in the coding region of exon 3 of ATF4 by polymerase chain reaction (PCR) and directly two-tailed sequencing. The three SNPs were moderately polymorphic loci and were in Hardy-Weinberg equilibrium. The combination of the three SNPs produced 4 haplotypes and 10 diplotypes. Association analysis showed that the g.149718665 AÂ >Â G locus was significantly associated with eggshell thickness, and genotype GG was favourable in increasing layer duck eggshell thickness. Diplotype H2H2 was more favourable for eggshell weight, thickness and strength than the other 9 diplotypes, which revealed that haplotype H2 may have a positive effect on eggshell calcium deposition. Thus, the three SNPs of ATF4 may be used as markers in selection for improved eggshell quality in layer ducks.

Dried Cassava Residue in Laying Quail Feeding

ABSTRACT This study evaluated the performance, egg quality, relative weight of the gastrointestinal organs, and the intestinal morphometry of laying quails fed diets containing levels of dried cassava residue (DCR). A total of 120 150-day-old Japanese quails were distributed in a completely randomized design with five treatments (0.0; 2.5; 5.0; 7.5; and 10.0% of DCR), four replicates, and six birds per experimental unit. The dietary inclusion of DCR did not affect (p>0.05) performance, internal egg quality, yolk color, and the values of villus height, crypt depth, and villus height/crypt depth ratio for the segments of the small intestine. However, a linear increase (p<0.05) was found for eggshell thickness, relative weight of the gizzard, and small intestine with increased dietary levels of the residue. For the relative weight of the pancreas, a quadratic effect (p<0.05) was observed, with the lower relative weight estimated at 4.04% DCR inclusion. Comparing to the control group (0% of DRC inclusion) the quails fed 5% of DRC showed a lower relative weight of the pancreas. The inclusion of up to 10% of dried cassava residue in laying quail’s diets does not interfere with the performance. Among the organs of gastrointestinal tract, the inclusion of dried cassava residue increased the relative weight of gizzard and small intestine. In addition, it improves eggshell quality by increasing eggshell thickness.

Dietary supplementation with protected calcium effects production and egg quality of Hy-line brown laying hens

Context Currently, the commonly used dietary calcium sources are not sufficiently bioavailable to be used for eggshell formation or bone health in laying hens. Protected calcium, a blend of calcium and medium-chain fatty acids with matrix coating, may exert an effective absorption and metabolism ability for calcium consumption in the laying hen. Aims The present study was conducted to evaluate the effects of protected-calcium supplementation on egg production, egg quality, and serum calcium and phosphorus concentrations in laying hens. Methods In total, 144 Hy-line brown laying hens (25 weeks old) were randomly allotted to three treatments (8 replicates with 6 hens, 1 hen per cage) in a 10-week trial. Treatments consisted of corn–wheat–soybean meal-based basal diet with limestone (coarse limestone:fine limestone = 50:50) as a calcium source (CON) or basal diet supplemented with 0.5% (P1) or 1% (P2) protected calcium in substitution for an equal quantity of coarse limestone. Data were statistically analysed using linear and quadratic contrast with the GLM procedure of SAS. Probability values of &amp;lt;0.05 indicate significance. Key results At Weeks 31–33 and 35, the cracked-egg rates were lower in the P1 and P2 groups than in the CON group (P &amp;lt; 0.05; linear, P &amp;lt; 0.05) and, at Weeks 29 and 34, the cracked-egg rates in the P2 group were also significantly (P &amp;lt; 0.05) decreased. At Weeks 26, 30 and 32, the Haugh units in the P2 group were significantly (P &amp;lt; 0.05) higher than those in the CON group. In addition, eggshell strength was increased significantly (P &amp;lt; 0.05) in the P2 group at Weeks 26, 27 and 31–35. The serum calcium concentration of the P2 group was significantly (P &amp;lt; 0.05) greater than that of the CON group in the morning. Conclusions In conclusion, a replacement of limestone with 1% protected calcium can increase eggshell quality. Implications Protected-calcium supplementation can be used in practice for decreasing the breakage of eggs.

Organic trace minerals improve eggshell quality by improving the eggshell ultrastructure of laying hens during the late laying period

The objective of this study was to investigate the effects of low inclusion levels of organic trace minerals (iron, copper, manganese, and zinc) on performance, eggshell quality, serum hormone levels, and enzyme activities of laying hens during the late laying period. A total of 405 healthy hens (HY-Line White, 50-week-old) were randomly divided into 3 treatments, with 9 replications per treatment and 15 birds per replication. The dietary treatments included a basal diet supplemented with inorganic trace minerals at commercial levels (CON), a basal diet supplemented with inorganic trace minerals at 1/3 commercial levels (ITM), and a basal diet supplemented with proteinated trace minerals at 1/3 commercial levels (TRT). The trial lasted 56 D (8 wk). Compared with the CON group, the ITM group showed decrease in (P < 0.05) egg production, eggshell strength, eggshell palisade layer, palisade layer ratio, serum estrogen, luteinizing hormone, glycosaminoglycan concentration, and carbonic anhydrase activity and increase in (P < 0.05) egg loss and mammillary layer ratio. However, the TRT group almost kept all the indices close to the CON group (P > 0.05). Furthermore, hens fed with low inclusion levels of organic trace minerals had smaller mammillary knobs (P < 0.05) than those in the CON and ITM groups. In conclusion, hens fed with low inclusion levels of proteinated trace minerals had better performance and eggshell strength than those fed with identical levels of inorganic compounds; organic trace minerals improved eggshell quality by improving the eggshell ultrastructure of laying hens during the late laying period.

Dietary chloride levels affect performance and eggshell quality of laying hens by substitution of sodium sulfate for sodium chloride

The objective of this study was to evaluate the effect of dietary chloride (Cl) levels on performance, eggshell mechanical quality, and ultrastructure in layers based on the substitution of sodium chloride (NaCl) by sodium sulfate (Na2SO4). Three hundred sixty Jing Brown laying hens aged 43 wk were randomly divided into 5 groups and fed with corn–soybean meal diets containing 0.06, 0.10, 0.15, 0.20, and 0.25% total Cl inclusion. Every group had 8 replicates of 9 birds each. The feeding trial lasted for 12 wk. The results showed dietary 0.06% Cl due to complete substitution of NaCl by Na2SO4, depressed performance (P < 0.05) from 45 to 54 wk of age, increased serum creatinine level (P < 0.05), and caused visible renal tubular atrophy. Dietary Cl levels quadratically affected breaking strength, thickness, and weight of eggshell (P < 0.05). Better eggshell quality could be obtained when NaCl was partly replaced by Na2SO4 in laying hen diets maintaining Cl level at 0.10 or 0.15%. Moreover, the eggshell ash content was affected by Cl levels in a quadratic (P < 0.001) manner, with higher values observed in the 0.10 and 0.15% Cl groups (P < 0.05). Besides, the eggshell ultrastructural data showed that the total thickness and effective thickness significantly increased (P < 0.05) and mammillary thickness decreased (P < 0.05) in the group of dietary 0.15% Cl compared with the groups of 0.06 and 0.25% Cl. In conclusion, the complete substitution of dietary NaCl by Na2SO4 may induce Cl deficiency and depress laying performance and eggshell quality. Na2SO4 could partly replace NaCl in diets for laying hens (43–54 wk of age) without adverse effects on performance at the dietary Cl level from 0.10 to 0.25%. Better eggshell quality could be obtained when NaCl was partly replaced by Na2SO4 in laying hen diets maintaining Cl level at ∼0.15%.

Response of three laying hen genotypes to two feed calcium levels

The present study aimed to evaluate the effect of two dietary Ca levels (3.00% vs 3.50%) in three hen genotypes (ISA Brown, Bovans Brown and Moravia BSL) on their laying performance and quality of their eggs. In order to evaluate the response to dietary Ca, an experiment was conducted with 300 laying hens. One hundred birds from each genotype were divided into 10 replicates (10 birds/cage/Ca level). To reveal the differences, the following characteristics were measured: hen-day egg production percentage, daily feed intake, egg weight, albumen and yolk weights, Haugh unit, eggshell colour, eggshell weight, eggshell thickness, eggshell strength, egg shape index and eggshell index. A higher Ca level significantly increased the hen-day egg production percentage of Bovans Brown and Moravia BSL, while ISA Brown laying hens had the higher egg production percentage at a lower dietary Ca level (85.97% vs 82.41%). No significant effect of dietary Ca level was observed on any internal egg quality measurements except the Haugh unit. However, the dietary Ca level significantly affected some of external egg quality measurements, namely eggshell colour (P &amp;lt; 0.001), eggshell weight (P = 0.003) and eggshell strength (P = 0.012). The results of the present study show that laying performance and egg quality parameters responded differently according to hen genotype and dietary Ca level. Bovans Brown and Moravia BSL laying hens required higher levels of Ca to keep egg production high, while the eggshell quality measurements were better at the lower dietary Ca level. Thus, it is recommended to adjust the Ca levels in feed to the nutritional requirements of laying hens.

Complete replacement of soybean meal with defatted black soldier fly larvae meal in Shaver White hens feeding program (28–43 wks of age): impact on egg production, egg quality, organ weight, and apparent retention of components

Effects of total replacement of soybean meal (SBM) with defatted black soldier fly larvae meal (BSFLM) on egg production and quality, organ weight, and apparent retention (AR) of components were investigated in Shaver White hens from 28 to 43 wk of age. A total of 108 birds, (6 birds/cage) were assigned to three diets (6 replicates/diet). Diets were control corn–SBM diet and two additional diets made with the addition of either 10 or 15% BSFLM. Diets met or exceeded breeder specifications, contained TiO2 as an indigestible marker, and were prepared in pellet form. Birds had free access to feed and water throughout the experiment. Hen-day egg production (HDEP) was monitored daily. Feed intake (FI) and body weight (BW) were monitored in 4-wk intervals. All eggs laid on the sixth day of wks 31, 35, 39, and 43 were used for egg weight (EW), Haugh units (HU), yolk color (YC), shell breaking strength (SBS), and shell thickness (ST). Excreta samples were collected for 3 consecutive days on wk 33 for AR and two birds/cage were necropsied at the end. There were no (P > 0.05) diet effects on HDEP, FI, and HU. Inclusion of BSFLM linearly decreased (P < 0.05) egg mass and feed conversion ratio (FCR) and quadratically increased (P < 0.05) BW. There was no (P > 0.05) interaction between diet and sampling time point on egg quality parameters. Inclusion of BSFLM increased SBF and YC linearly (P < 0.05) and ST quadratically (P = 0.028). Inclusion of BSFLM quadratically (P ≤ 0.01) reduced empty ceca weight and increased liver weight and had no effect (P > 0.05) on gizzard, small intestine, and pancreas weights. Feeding BSFLM linearly (P = 0.001) and quadratically (P = 0.007) increased apparent metabolizable energy (AME). Data showed that defatted BSFLM resulted in deeper orange yolks and improved eggshell quality; however, unfavorable FCR linked to lighter eggs as well as heavier birds and liver warrants further investigations.

Dietary supplementation of Eucalyptus leaves enhances eggshell quality and immune response in two varieties of Japanese quails under tropical condition

The effect of dietary supplementation of Eucalyptus leaves (EL) powder on productive performance and immune response in 2 varieties of Japanese quail was investigated. A total of 180 twelve-week-old laying Japanese quails from 2 color varieties (gray and white) were randomly assigned and distributed according to a completely randomized design in a 3 × 2 factorial arrangement (dietary treatment × variety) forming 6 subgroups (30 each). EL were mixed with the diet in 3 levels (0, 0.1, and 0.2%). Each hen was individually housed in a wire cage of laying batteries and kept in an open house under hot environmental temperature. Productive traits were determined for an experimental period of 6 wk. Egg quality, carcass traits, blood parameters, and immune response were also determined. The results indicated that the productive traits were not significantly affected by EL supplementation. Shell quality and broken eggs significantly improved in quails fed a diet containing EL compared with those in the control. The quails fed a diet supplemented with 0.1% EL exhibited significantly higher cellular mediated and humoral immune responses than those in the other treatment groups. Glutathione peroxidase activity tended to be significantly increased by the dietary administration of EL at the level of 0.2%. Concerning quail varieties, it could be noticed that the gray quails exhibited higher productive performance, shell quality, and cellular immunity than the white counterparts. It could be concluded that supplementing a diet with 0.1 EL as a natural feed additive greatly enhances eggshell quality and immunocompetence and reduces number of broken eggs of Japanese quails raised under high environmental temperature.

Effect of high concentrations of dietary vitamin D3 on pullet and laying hen performance, skeleton health, eggshell quality, and yolk vitamin D3 content when fed to W36 laying hens from day of hatch until 68 wk of age

The objective of this experiment was to investigate the effects of various dietary concentrations of vitamin D3 (D3) on pullet and laying hen performance, eggshell quality, bone health, and yolk D3 content from day of hatch until 68 wk of age. Initially, 440 Hy-line W36-day-old chicks were randomly assigned to 5 dietary treatments: 1,681 (control); 8,348; 18,348; 35,014; 68,348 IU D3/kg. At 17 wk of age, pullets were assigned to experimental diets with 12 replicate groups of 6 birds. At 17 wk of age, pullets fed diets containing 8,348 and 35,014 IU D3/kg had an increased bone mineral density in comparison to the control fed birds (P ≤ 0.01). Body weights of pullets fed the diet with 68,348 IU D3/kg were lower than other treatments (P ≤ 0.01). Hen-housed egg production (HHEP) of hens fed the 35,014 IU D3/kg diet was increased in comparison to control-fed hens (P ≤ 0.01), whereas HHEP of those fed 68,348 IU D3/kg diet was reduced in comparison to all other treatments (P ≤ 0.01). Shell breaking strength of eggs from hens fed 8,348, 35,014 and 68,348 IU D3/kg was increased in comparison to eggs from control-fed birds (P ≤ 0.01). Fat-free tibia ash content of hens fed any of the diets supplemented with D3 (8,348 to 68,348 IU D3/kg) was increased in comparison to control-fed hens (P ≤ 0.05). Yolk D3 content increased linearly with dietary D3 and the D3 transfer efficiency for the control, 8,348 IU, 18,348 IU, 35,014 IU, and 68,348 IU D3 treatments were 8.24, 10.29, 11.27, 12.42, and 12.06%, respectively. These data suggest that supplementation of dietary D3 up to 35,014 IU D3/kg feed maintained if not increased laying hen performance and enhanced pullet and laying hen skeletal quality as well as yolk D3 content and eggshell quality. Feeding pullets at a higher level 68,348 IU of D3 resulted in reduced growth and ultimately decreased performance of laying hens.

Concentration of egg white antimicrobial and immunomodulatory proteins is related to eggshell pigmentation across traditional chicken breeds

Eggshell colour, quality, and biosafety of table eggs are of significant commercial interest. To date, there have been few studies investigating the relationship between eggshell pigmentation and internal egg quality in commercially bred birds. Moreover, the genetic basis and mechanisms behind the effects of extrinsic factors on deposition of antimicrobial compounds in egg white and eggshell pigments are not fully understood. In the present study, we evaluate the effect of chicken breed identity, eggshell pigmentation and the role of extrinsic factors (year and breeder identity) on variability in the concentrations of 2 major egg white antimicrobial proteins (AMPs), lysozyme (LSM), and ovotransferrin (OVOTR), across 23 traditional chicken breeds. We found that chicken breed identity and eggshell pigmentation explained most variability in the concentration of egg white LSM and OVOTR. Year and breeder identity were also significant predictors of egg white LSM and OVOTR variability, and showed selective effects on the deposition of both AMPs in egg white. We also documented a positive correlation between concentration of egg white LSM and eggshell cuticle protoporphyrin in tinted and dark brown eggs, but not in brown, white, and blue eggs. We assume that a combination of both intrinsic genetic and hormonally regulated extrinsic factors is responsible for this relationship and for the variability in egg white AMPs. In this study, we demonstrate the existence of a relationship between eggshell pigmentation and egg white AMPs content in the eggs of traditional chicken breeds that may advertise the egg's antimicrobial potential and biosafety. These findings provide novel insights into the relationship between eggshell pigmentation and egg internal quality and may stimulate the recovery and exploitation of traditional chicken breeds for egg production, where the demands for egg quality and biosafety, in conjunction with animal welfare, are a priority.