Effect of Limestone or Extruded Eggshell on Egg and Eggshell Quality of Laying Hens

Study on changes in egg quality traits and genetic parameters of white leghorn hens from 35 to 100 weeks of age.

The study was conducted to investigate the effect of dietary diatomaceous earth (DE) on egg quality traits in deep litter hens. A total of 280 Lohmann Brown pullets were at 20 weeks of age divided into 4 groups. Three groups were fed on one of the three experimental diets supplemented with 2%, 3% or 4% DE, while the fourth group was fed on a control diet without DE supplementation. Each group had seven replicates of 10 birds. One egg was collected randomly per replicate (for a total of 7 eggs per group), weighed and determined for: yolk weight, albumen weight, eggshell weight, eggshell thickness, specific gravity, albumen height, yolk height, yolk colour and Haugh unit. Findings showed that DE supplementation resulted into significant (p<0.05) increase in eggshell weight and yolk height. Dietary supplementation with DE in the current study was, however, not effective on other egg quality parameters such as on eggshell weight percentage, egg specific gravity, yolk colour and Haugh unit. However, results of the study also showed that DE supplementation improved significantly (p<0.05) egg quality especially by improving viscosity as flocks grew older as compared to younger flocks. Further research should focus on the effect of dietary DE on eggshell and bone strength of layer birds. Research should also explore the interactions among the minerals found in DE (e.g. calcium, phosphorus and magnesium) and how these interactions affect egg quality in laying hens.

The external and internal qualities of 120 eggs (60:60) from Isa Brown (IB) and Bovan Nera (BN) layer breeders were evaluated at 15th and 30th week of their production. The genotypes differed significantly (P<0.09) m external egg quality traits except egg weight and egg length. IB recorded higher values in egg width, eggshell weight, eggshell thickness, shape index and shell ratio than BN, while the reverse trend was for egg length. This implies that IB genotype produced eggs with thicker shells than BN, which invariably will lead to a reduction in the rate of cracks and leakages both on the farm and in the hatchery thereby enhancing better hatchability. The age effect was significant (P<0.05) for all the external egg quality traits. The analysis showed that eggs produced at 30th week were better in terms of external quality traits with the exception of egg shape index. There was positive and significant (P <0.05) interaction effect between genotype and age on eggshell width and shell ratio but not for other traits. As regards internal egg quality traits, the genotypes differed significantly (P<0.05) in all the traits except yolk width, yolk height and albumen weight. IB recorded higher (P<0.05) values in yolk weight, albumen width and yolk ratio than BN, while the latter recorded higher values in albumen height, albumen ratio and haugh unit (HU) than the former The effect of age on internal traits was positive and significant (P<0.05) with the exception f yolk width, albumen width, yolk ratio and albumen ratio. The result showed that the 30th week analyses recorded higher (P<0.05) values in these traits than 15th week. This implies that the quality of breeding eggs improves with the advancing age of the birds. Breed x age interactions were significant for yolk weight and albumen width but not found for other traits. IB genotype was considered the best for external egg quality traits and produced thicker eggshell. However, BN genotype produced superior egg quality than lB having recorded higher values (P< 0.05) in HU, which is a determinant of egg quality

Genetic parameters were estimated for egg production, egg quality, and eggshell colors in eight lineages of Brazilian laying hens. Age at first egg (AFE), total egg production up to the 45th week (PROD), egg weight (EW), albumen height (AH), yolk color (YC), the Haugh units (HU), eggshell strength (ESS), eggshell thickness (EST), yolk weight (YW), eggshell weight (ESW), and eggshell color (L*, a*, and b*) were measured in 2030 eggs obtained from 645 laying hens. Variance components were estimated from a mixed animal model, which included the fixed effects of contemporary groups, cage location, and hen line, and the additive genetic, permanent environmental, and residual as random effects. In general, heritabilities were low to moderate (h2 = 0.11 to 0.48). Genetic correlations among eggshell quality traits were moderate to high (0.36 and 0.69). High genetic correlations were obtained between the eggshell color traits [rg = -0.90 (L* and a*); rg = -0.64 (L* and b*); and rg = 0.65 (a* and b*)]. Results suggest that EW is strongly correlated with ESW, but the genetic correlations between EW and ESS and between EW and EST were low. Genetic correlations between L* and eggshell quality traits were low to moderate, suggesting that L* has little or no relation with external egg quality. However, genetic correlations between a* and b* values and eggshell quality traits were high. The genetic correlations between eggshell color and eggshell quality traits were low, suggesting that the eggshell color does not influence external egg quality. Genetic correlations between PROD and egg quality traits were negative and varied between -0.42 and -0.05. This antagonistic relationship emphasizes the importance of adopting breeding schemes that allow the simultaneous genetic progress of these traits by considering their genetic correlation and economic relevance, such as the selection index.

Effect of rosemary (Rosmarinus officinalis) leaf meal supplementation on production performance and egg quality of laying hens

This study was designed to determine the effect of egg weight on internal and external egg quality characteristics of Isa brown egg layer chickens. A total number of 105 eggs collected within 24 hours of lay were used for the study. Eggs were numbered, weighed and classified into three egg weight groups: Light (less than 49.99 g), medium (50 to 55 g) and heavy (greater than 55 g) egg weight groups. Data were collected on internal egg quality characteristics (yolk height, albumen height, albumen length, albumen width, Haugh unit, yolk index, albumen index and yolk diameter) and external egg quality characteristics (egg length, egg width, oblong circumference, egg shell weight, egg shape index and egg shell thickness). Data were analyzed using Statistical Package for the Social Sciences (SPSS) version 20.0. Egg weight had significant (P 0.05) affect Haugh Unit, yolk index, albumen index, and albumen length of the three egg weight groups. However, significant differences (P < 0.05) were observed among the light, medium and heavy egg weight groups in terms of yolk height, yolk diameter, and albumen height and albumen width. Positive correlations (P < 0.05) were observed between egg weight and egg length, egg width, oblong circumference, eggshell weight and eggshell thickness. Egg weight also correlated positively (P < 0.05) with yolk height, yolk diameter, albumen height and width.

Heritabilities and genetic and phenotypic correlations of egg quality traits in brown-egg dwarf layers

Objetivo. Evaluar el efecto del aceite crudo de palma (ACP) sobre la calidad del huevo almacenado por varios días a diferentes temperaturas. Materiales y métodos. Un total de 240 gallinas de 28 semanas se alimentaron con dietas con 30g/kg de aceite de soya (AS) o ACP. Después de 12 semanas, muestras de huevos se almacenaron durante 0, 4, 8 y 12 días a 4, 12 y 24°C. Las características de calidad del huevo fueron evaluadas. Resultados. El huevo y la albúmina de gallinas en la dieta con ACP fueron más pesados que aquellos en la dieta con AS (p&lt;0.05). La alta temperatura de almacenamiento redujo el peso del huevo, albúmina y yema, unidades Haugh (UH), altura de la albúmina y la yema, pH y color (p&lt;0.05), pero aumentó el ancho de la albúmina y la yema, y la longitud de la albúmina (p&lt;0.05). A medida que aumentaba el tiempo de almacenamiento, el peso del huevo, el peso y la altura de la albúmina, y la altura de la yema, el pH y el color se redujeron (p&lt;0.05). Sin embargo, el peso y el ancho de la yema, el ancho y la longitud de la albúmina aumentaron (p&lt;0.05). Conclusiones. Las gallinas en la dieta con ACP tuvieron huevos y albuminas más pesadas que las de las de la adieta con AS.

A study was carried out to determine the influence of the feather genotype, storage duration, temperature and method on the internal and external qualities of chicken table eggs. A total of 864 table eggs collected from naked neck (Nanaff), frizzle (nanaFf) and normal feathered (nanaff) birds were used in the study. A Completely Randomized Design of four factors namely, feather genotypes, storage temperatures (5ºC and 26ºC), storage duration (0, 7, 14, 21 and 28 days) and storage methods (with or without vegetable oil application) was used. The GLM procedure of GenStat (17th Edition) was used to determine the effects of the four factors and their interactions on external qualities (egg weight, length, and width, shell weight and thickness) and internal qualities (albumen height and weight, yolk height, weight, diameter and colour and Haugh unit) of table eggs. The effect of chicken genotype on proximate composition and nutritional values of table eggs were also determined. Feather genotype had significant (P&lt;0.05) effect on yolk colour and weight whilst storage duration, temperature and method had significant (P&lt;0.05) effects on all the internal qualities of eggs studied except effect of storage duration on yolk colour. The 2-way and 3-way interactions of the factors studied were important sources of variation for many of the internal qualities of eggs studied. With the exception of storage temperature, the other factors studied had significant (P&lt;0.05) effects on many of the external qualities of eggs. The interactions of the factors were not significant (P&gt;0.05) sources of variation for most of the external qualities of eggs. Mutant feather genes (Na and F) positively influence egg qualities which could be utilised to segment the commercial chicken egg market. Keywords: Feather, Frizzle, Naked neck, Yolk colour, Nutritional value.

1. The objective was to estimate heritability, genetic and phenotypic correlations for egg quality traits of Iranian native fowl at the Yazd Breeding Centre. 2. External and internal egg quality traits were measured on 1200 eggs from 794 hens of the 6th generation. A multivariate animal model with restricted maximum likelihood procedure was applied to estimate heritability, genetic and phenotypic correlations for egg quality traits using ASREML. 3. Heritability estimates for external egg quality traits ranged from 0·18 to 0·57 and for internal egg quality traits from 0·24 to 0·60. 4. For external egg quality traits, genetic correlation between egg weight and eggshell thickness (EST) was positive (0·36) and EST showed high genetic correlations with eggshell weight (0·84) and eggshell strength (0·55). This implies that heavier eggs tend to have thicker and stronger shells. 5. For internal egg quality traits, albumen height showed high positive genetic correlations with albumen weight (0·52), albumen index (0·98), yolk height (0·72) and yolk index (0·57). 6. Our results show that it is feasible to improve egg quality in Iranian fowl through selection for albumen height.

Aim:The experiment was carried out to evaluate different external and internal egg quality traits and to figure out their mode of inheritance from a set of hierarchically classified data.Materials and Methods:The data collected from 548 progenies (1 egg from each progeny) of 282 dams mated to 47 sires (1 sire mated to 6 dams) of a White Leghorn flock were used in the present study. Phenotypic means and their standard errors were calculated for all the quality traits. Heritabilities were estimated for these traits separately from “sire,” “dam” and “sire+dam” (full-sib) components of variance using Statistical Package for Social Sciences-17 program.Results:External quality traits such as; egg weight, length, width, shape index, surface area, shell weight, shell thickness, shell ratio, and internal quality traits such as; length, width, height, and weight of albumen and yolk, albumen index, albumen ratio, Haugh unit (H.U.), yolk diameter, yolk index, yolk ratio, and yolk albumen ratio were measured in 548 eggs of the experimental White Leghorn flock. The eggs were found to have optimum weight (57.78±0.20 g), shape index (73.53±0.18) and shell characteristics (6 g, 0.32 mm) as per its genetic potential. Higher values for albumen height (8.41±0.04) mm and H.U. (92.00±0.19) are attributable to the freshness of eggs and proper age of hens. Heritability estimates from “sire” component of variance were higher than “dam” and “sire+dam” components for the traits like egg weight, length, width, shape index, surface area, albumen width, albumen index, H.U., yolk width, yolk height, yolk weight, and yolk index whereas for rest of the traits the values estimated from “dam” component were higher. Estimates from “sire+dam” component were intermediate to the estimates derived from “sire” and “dam” components.Conclusion:The heritability estimates from different egg quality traits were moderate to high. Since most of the traits have high heritability values, these traits can be improved by mass selection.

In this study, sixteen egg quality traits, including egg weight, albumen weight, yolk weight, eggshell weight, albumen weight ratio, yolk weight ratio, eggshell weight ratio, yolk color, eggshell color, egg height, egg width, shape index, albumen height, Haugh unit, eggshell thickness, and eggshell strength were investigated in 12 strains of Korean native chicken using 600 eggs from birds at 38 weeks of age. Results showed that the Korean White Leghorn F strain had the highest egg weight of 62.7 g and the lowest (47.5 g) was observed in the Korean native chicken W strain. The Haugh unit was significantly different between strains. The mean Haugh unit for Korean native chicken ranged between 84.2 (L strain) and 76.0 (F strain), with an overall average of 79.9. Eggshells were the thinnest in Korean Rhode Island Red C and D strains (0.342 mm), whereas the highest eggshell thickness (0.393 mm) was observed in the Korean White Leghorn K strain. Korean Rhode Island Red C and D strains had low egg strength compared to that of other strains. Korean Cornish and Korean native chicken showed significant differences in egg quality traits between strains within breeds. Positive correlation coefficients were observed between egg weight and egg quality traits. The traits for color showed zero or low correlations with most egg quality traits. Egg shape index showed no correlation with most egg quality traits. Albumen height and the Haugh unit showed a positive correlation with albumen traits. Eggshell strength showed a positive correlation with eggshell traits.

700 Rhode Island Red (RIR) and 600 Bovans white exotic poultry breeds were maintained under intensive management by private poultry farm in Mekelle were studied for external and internal egg qualities.Weight of egg (g), length (cm) and width of egg (cm), shape index, egg shell thickness (mm) and egg shell weight (g) were studied as external egg quality traits while yolk and albumen weight (g), yolk and albumin height (mm), Haugh Unit (HU) and yolk color were recorded as internal egg quality traits of RIR and Bovans White.Among external egg quality Weight, length and width of egg of RIR was significantly higher (p<0.05)than Bovans White while shape index, egg shell thickness and egg shell weight (g) were found to be non significant.Among internal egg quality yolk and albumen weight, yolk and albumin height of RIR was significantly higher (p<0.05)than Bovans White while Haugh Unit (HU) and yolk color were found to be non significant.

In the search for alternative feed resources for laying hens, papaya pomace is available as industrial by‐product but information on its nutritive value is lacking. Dried papaya pomace was included in a common laying hen diet at 0%, 2.5%, 5% and 7.5% to evaluate its effect on egg production performance, egg quality and general health parameters in Bovan brown layers. For every inclusion level, three cages with ten 20‐week‐old layers were used, making a total of 120 hens. The effect of dried papaya pomace inclusion on egg production, egg quality and general health parameters was evaluated. Dried papaya pomace inclusion improved egg production and laying by 6.15% and 17% respectively, while it significantly decreased feed conversion ratio by 7.5%. Eggshell weight, thickness and strength of PP5 were higher than the control by 0.3 g, 0.8 mm and 0.43 kg/cm2, respectively. There was a significant improvement in albumin weight (by 1.5 g/L), albumin height (2.1 mm), yolk weight (0.4 g/L), yolk height (0.4 mm), yolk colour (4.4 points) and Haugh unit (8 points) due to PP5 treatment. Inclusion of papaya pomace at a level of 7.5% of layers diet had negative effect on Egg production, feed conversion ratio and interior and exterior egg quality traits. Inclusion of papaya pomace affected significantly serum total cholesterol, serum triglyceride, serum low density lipoprotein, serum high density lipoprotein, aspartate aminotransferase, alanine aminotransferase and white blood cell count. However, all blood traits of the experimental animals were within the normal ranges reported for layers. Inclusion of papaya pomace in 5% of layers commercial diets improves egg production and quality without negative impact on health while decreasing feeding cost.

Availability of the complete genome sequence as well as high-density SNP genotyping platforms allows genome-wide association studies (GWAS) in chickens. A high-density SNP array containing 57,636 markers was employed herein to identify associated variants underlying egg production and quality traits within two lines of chickens, i.e., White Leghorn and brown-egg dwarf layers. For each individual, age at first egg (AFE), first egg weight (FEW), and number of eggs (EN) from 21 to 56 weeks of age were recorded, and egg quality traits including egg weight (EW), eggshell weight (ESW), yolk weight (YW), eggshell thickness (EST), eggshell strength (ESS), albumen height(AH) and Haugh unit(HU) were measured at 40 and 60 weeks of age. A total of 385 White Leghorn females and 361 brown-egg dwarf dams were selected to be genotyped. The genome-wide scan revealed 8 SNPs showing genome-wise significant (P<1.51E-06, Bonferroni correction) association with egg production and quality traits under the Fisher's combined probability method. Some significant SNPs are located in known genes including GRB14 and GALNT1 that can impact development and function of ovary, but more are located in genes with unclear functions in layers, and need to be studied further. Many chromosome-wise significant SNPs were also detected in this study and some of them are located in previously reported QTL regions. Most of loci detected in this study are novel and the follow-up replication studies may be needed to further confirm the functional significance for these newly identified SNPs.