The hen's egg: Relationships of seven characteristics of the strain of hen to the incidence of cracks and other shell defects

Carter, T. C.

doi:10.1080/00071667508416189

“…Similar correlations between shell colour and specific gravity have been reported by Godfrey (1949), Godfrey and Jaap (1949) and Grover et al (1980), and between shell colour and shell thickness by Godfrey (1949) and Godfrey and Jaap (1949), though Carter (1975) found a significant negative correlation between shell colour and shell thickness. The high and significant negative correlation reported by Carter (1975) between egg-shell colour and incidence of shell faults, emphasises the beneficial effect of shell colour on strength. Although did not find significant relationships between egg-shell colour and four measurements of shell strength, one of the two commercial strains used showed correlations between colour and thickness and between colour and breaking strength which were almost significant and similar to those mentioned above.…”

Section: Discussionsupporting

confidence: 85%

“…Shell thickness was not predicted more accurately with both specific gravity and shell colour as independent variables than by using specific gravity alone, confirming the results of , in which shell colour was not significantly related to non-destructive deformation and breaking strength, and contradicting those reported by Carter (1975) who found that shell colour was significantly associated with reduction of shell faults. Shell thickness was predicted most accurately when specific gravity and egg weight were used as independent variables, even though the determination coefficient did not differ very much from that obtained using specific gravity alone.…”

Section: Discussionsupporting

confidence: 69%

“…Potts and Wash-467 burn (1974) found no significant correlation of shell colour and four measurements of shell strength (egg specific gravity, shell thickness, non-destructive deformation and breaking strength). Carter (1975) reported a relatively high and significant negative correlation between shell colour and shell thickness, which contradicts the belief that brown shells are thicker than white ones, and between shell colour and proportion of shell breakages, confirming the belief that the incidence of shell faults is less in heavily pigmented shells. All these results were obtained in commercial strains or stocks of brown-egg layers which had been exposed to commercial selection.…”

Section: Introductionmentioning

confidence: 52%

See 1 more Smart Citation

Relationship between egg‐shell colour and two measurements of shell strength in the Vasca breed

Campo

¹

,

Escudero

²

1984

British Poultry Science

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1. Egg-shell colour, egg specific gravity, shell thickness and egg weight were determined for 2080 eggs from three varieties of the Vasca, a Spanish brown-egg-laying hen. 2. Intermediate, positive and significant (P < 0·01) correlation coefficients were found between egg-shell colour and specific gravity (0·25), or shell thickness (0·21). There was a very high (0·84), significant (P < 0·01) correlation between the measures of shell strength. 3. Shell thickness was accurately predicted with both specific gravity and egg weight as independent variables (determination coefficient 0·74); eggshell colour did not explain any further variation. 4. All traits showed considerable departure from normality in the form of negative kurtosis (shell colour and specific gravity), positive kurtosis (shell thickness and egg weight), negative skewness (shell thickness) or positive skewness (egg weight). 5. Egg-shell colour, specific gravity and shell thickness were less in July, in old birds and in eggs laid in the morning. Differences in egg quality traits between the three varieties were not significant.

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“…The studied traits were egg albumen weight(g), yolk and shell weights(g), egg shape index as the percentage of egg width on egg length, shell without membranes thickness (mm), albumen height (mm) with micrometer. Egg surface area (cm 2 ) was calculated as the formula of Carter (1975); Eggshell density (g/cm 2 ) was calculated by the formula of Curtis et al (1985), Yolk weight %, albumen weight%, eggshell weight %, and yolk/albumen ratio were detected.…”

Section: Methodsmentioning

confidence: 99%

Direct and Maternal Genetics With Environmental Effect for Egg Quality and Hatchability of Gimmizah Chickens Selected for Body Weight

Boutrous¹

2021

EPSJ

0

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The present experiment was conducted on Gimmizah (GM) chickens selected for body weight at 12-wk of age through three generations aiming for detection the genetic components of direct, maternal and environmental effects of egg quality traits and hatchability. Second generation of GM chickens selected for body weight represent increase (p>0.05) of some egg quality traits such as hatching egg weight, egg shape index, egg surface area, egg shell density, eggshell thickness without membranes, albumen weight, albumen height, yolk weight, and egg shell weight compared with those for base population (G 0 ) and first generation (G 1 ). Generally, Additive genetic maternal was surpassed those for the additive genetic direct and permanent environmental hen effects for the most studied traits. Realized heritability estimates among the three selected generations proved that the records of direct estimate (h 2 a ) had highest value of heritability compared with those for maternal (h 2 m ) and permanent environmental hen effect (h 2 pe ) with respect to hens body weigh at 45-wk of age, hatching egg weight, egg surface area, eggshell thickness without membranes, albumen weight, albumen height, yolk weight ratio, eggshell weight, eggshell weight percent, albumen weight percent, and yolk/albumen ratio. Also, highly significant positive genetic correlations are detected between most of the studied egg quality traits and hatchability. Also, there are highly maternal positive maternal genetic correlations between hatching egg weight and each of egg shape index, eggshell thickness, albumen weight, albumen height, yolk weight, fertility, total embryonic mortality and hatchability of fertile eggs. The obtained results of low estimates of heritability for fertility and hatchability and the highly estimates for egg quality traits besides the highly direct and maternal genetic correlations suggesting the applicability of some egg quality traits in programming the selection index combining with body weight selection as indirect way for improving fertility and hatchability with body weight.

show abstract

“…The studied traits were egg albumen weight(g), yolk and shell weights(g), egg shape index as the percentage of egg width on egg length, shell without membranes thickness (mm), albumen height (mm) with micrometer. Egg surface area (cm 2 ) was calculated as the formula of Carter (1975); Eggshell density (g/cm 2 ) was calculated by the formula of Curtis et al (1985), Yolk weight %, albumen weight%, eggshell weight %, and yolk/albumen ratio were detected.…”

Section: Methodsmentioning

confidence: 99%

Genetic Response of Body Weight, Secondary Sexual Characters and Hatchability of Gimmizah Chickens Selected for Breast Circumference

Boutrous¹

2021

EPSJ

0

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The present experiment was conducted on Gimmizah (GM) chickens selected for body weight at 12-wk of age through three generations aiming for detection the genetic components of direct, maternal and environmental effects of egg quality traits and hatchability. Second generation of GM chickens selected for body weight represent increase (p>0.05) of some egg quality traits such as hatching egg weight, egg shape index, egg surface area, egg shell density, eggshell thickness without membranes, albumen weight, albumen height, yolk weight, and egg shell weight compared with those for base population (G 0 ) and first generation (G 1 ). Generally, Additive genetic maternal was surpassed those for the additive genetic direct and permanent environmental hen effects for the most studied traits. Realized heritability estimates among the three selected generations proved that the records of direct estimate (h 2 a ) had highest value of heritability compared with those for maternal (h 2 m ) and permanent environmental hen effect (h 2 pe ) with respect to hens body weigh at 45-wk of age, hatching egg weight, egg surface area, eggshell thickness without membranes, albumen weight, albumen height, yolk weight ratio, eggshell weight, eggshell weight percent, albumen weight percent, and yolk/albumen ratio. Also, highly significant positive genetic correlations are detected between most of the studied egg quality traits and hatchability. Also, there are highly maternal positive maternal genetic correlations between hatching egg weight and each of egg shape index, eggshell thickness, albumen weight, albumen height, yolk weight, fertility, total embryonic mortality and hatchability of fertile eggs. The obtained results of low estimates of heritability for fertility and hatchability and the highly estimates for egg quality traits besides the highly direct and maternal genetic correlations suggesting the applicability of some egg quality traits in programming the selection index combining with body weight selection as indirect way for improving fertility and hatchability with body weight.

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The hen's egg: Relationships of seven characteristics of the strain of hen to the incidence of cracks and other shell defects

Cited by 9 publications

References 19 publications

Relationship between egg‐shell colour and two measurements of shell strength in the Vasca breed

Relationship between egg‐shell colour and two measurements of shell strength in the Vasca breed

Direct and Maternal Genetics With Environmental Effect for Egg Quality and Hatchability of Gimmizah Chickens Selected for Body Weight

Genetic Response of Body Weight, Secondary Sexual Characters and Hatchability of Gimmizah Chickens Selected for Breast Circumference

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