Genetic parameter estimates and strain comparisons of egg compositional traits<sup>1</sup>

Rodda, D. D.; Friars, G. W.; Gavora, J. S.; Merritt, E. S.

doi:10.1080/00071667708416386

Cited by 30 publications

(13 citation statements)

References 7 publications

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“…Likewise, the positive maternal-direct genetic correlations between yolk traits and HATCH are in line with the positive effects of yolk traits on hatchability found by Nestor & Noble (1995). The negative maternal -direct genetic correlation between albumen weight and HATCH is probably due to the high positive correlation with egg weight (Rodda et al, 1977;Hartmann et al, 2000). There was also a positive maternal-direct genetic correlation between albumen dry matter and HATCH in this study.…”

Section: Relationships Between Reproduction Traits and Egg Compositionsupporting

confidence: 84%

“…It should be kept in mind that the present genetic parameters are only valid for the range of values of the egg composition traits in the studied population. The positive genetic correlations between FERT and albumen weight and yolk weight are probably due to the autocorrelation between the traits and egg weight (Rodda et al, 1977;Hartmann et al, 2000).…”

Section: Relationships Between Reproduction Traits and Egg Compositionmentioning

confidence: 97%

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Genetic Relations between Reproduction, Chick Weight and Maternal Egg Composition in a White Leghorn Line

Hartmann¹,

Strandberg²,

Rydhmer³

et al. 2002

Acta Agriculturae Scandinavica, Section A - Animal Science

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Lö vsta, SE-755 97 Uppsala, Sweden). Genetic relations between reproduction, chick weight and maternal egg composition in a White Leghorn line.Selection is a viable way to increase egg dry matter, an important trait for the egg processing industry, but simultaneously a change in the embryonic environment takes place. The main purpose of this study was to estimate genetic parameters for the percentage of fertile eggs of eggs set (FERT), percentage of eggs hatched of fertile eggs (HATCH), percentage of live chicks 2 weeks post-hatch of hatched eggs (SURV:h) and of fertile eggs (SURV), and their genetic correlations with egg weight, albumen weight, yolk weight, yolk proportion, albumen dry matter and mean chick weight in a White Leghorn selection line. Direct and maternal heritabilities were low for FERT, HATCH and SURV, and non-existent for SURV:h. All direct -direct genetic correlations between reproduction traits and egg composition traits were not signi cant. Maternal-direct genetic correlations between HATCH and egg weight, albumen weight, yolk weight, yolk proportion and albumen dry matter were ¼ 0.22, ¼ 0.30, 0.28, 0.52 and 0.26, respectively. Similar correlations were found between SURV and egg composition traits. No signi cant genetic relationship was found between chick weight and post-hatc h survival. In conclusion, within the range of values for egg composition in this study, selection for an increased egg dry matter should not impair reproduction.

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Section: Relationships Between Reproduction Traits and Egg Compositionsupporting

confidence: 84%

Section: Relationships Between Reproduction Traits and Egg Compositionmentioning

confidence: 97%

Genetic Relations between Reproduction, Chick Weight and Maternal Egg Composition in a White Leghorn Line

Hartmann¹,

Strandberg²,

Rydhmer³

et al. 2002

Acta Agriculturae Scandinavica, Section A - Animal Science

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“…Nevertheless, Rodda et al (1977) and Friars et al (1978) reported significant differences between strains selected for high egg production and unselected control strains in albumen percent solids and in percent albumen of the whole eggs but no strain effects on the yolk percent solids. Hafez et al (1955), Marion et al (1964), Varadarjulu and Cunningham (1972), and Rodda et al (1974) also have observed significant strain effects for various egg composition traits.…”

Section: Introductionmentioning

confidence: 94%

Composition of Eggs by Commercial Size Categories: Effects of Genetic Group, Age, and Diet

et al. 1983

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Effects of genetic group, age, and dietary protein level on composition of eggs within the commercial size categories were studied in two Leghorn control strains formed in 1950 and 1958, two corresponding strains selected for high egg production and related traits, their reciprocal crosses, and a commercial Leghorn stock.Mean hen-housed egg production to 385 days was 154, 184, 197, and 191 eggs, and 385-day egg weight was 59.4, 63.1, 64.4, and 62.0 g for the control strains, selected strains, strain crosses, and commercial stock, respectively. In the eggs graded as large, wet and dry yolk weights, percent of yolk, and dry yolk/albumen ratio increased while wet albumen weight and percent of albumen decreased as dietary protein level increased from 15 to 19%. No such effects were observed in the medium or extra large eggs.Within each egg size category, wet and dry yolk weight and percent of yolk increased and wet and dry albumen weight, percent of albumen, albumen percent solids, and shell weight decreased with age. These trends were reversed by forced molting between the sixty-fourth and seventy-first weeks of age but they resumed afterwards.There was no heterosis for any egg composition trait and no genetic group effects on yolk percent solids. Within the same commercial size category, eggs of the control strains had lower albumen percent solids than those of selected strains or the commercial stock and contained more yolk and less albumen and shell. These differences reflect changes in the composition of the eggs from hens that have been under selection for increased production since the control strains were formed. (

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“…Recently Rodda et al (1977) has reported some genetic relation between egg weight and conipositional traits and several papers have appeared on the effect of breed or inheritance on cholesterol and fat content of eggs (Edwards et al, 1960; Clark et al, 1964;Cunningham et al, 1974; Washburn et al, 1974).…”

Section: Introductionmentioning

confidence: 97%

“…For marketing purposes eggs are usually classified only by size, shell strength, and whatever can be seen by passing light through them. Therefore breeders have little incentive t o obtain any changes in the internal composition.Recently Rodda et al (1977) has reported some genetic relation between egg weight and conipositional traits and several papers have appeared on the effect of breed or inheritance on cholesterol and fat content of eggs (Edwards et al, 1960; Clark et al, 1964;Cunningham et al, 1974; Washburn et al, 1974).The main objective of the project reported here was to look for a possible quantitative difference in the protein and lipid components of the eggs as a result of specialized selection for high rate of lay and high egg weight. Furthermore, we looked for relations bettveen blood parameters, production parameters and egg composition traits.…”

mentioning

confidence: 99%

Lipids and Proteins in Eggs and Blood Serum from two Strains of Hens

Rotenberg¹,

S⊘rensen²

1978

Acta Agriculturae Scandinavica

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IntroductionIn evaluating genetic improvement of the egglaying capacity of hens !ittle attention has been given t o date t o the internal composition of the eggs. For marketing purposes eggs are usually classified only by size, shell strength, and whatever can be seen by passing light through them. Therefore breeders have little incentive t o obtain any changes in the internal composition.Recently Rodda et al. (1977) has reported some genetic relation between egg weight and conipositional traits and several papers have appeared on the effect of breed or inheritance on cholesterol and fat content of eggs (Edwards et al., 1960; Clark et al., 1964;Cunningham et al., 1974; Washburn et al., 1974).The main objective of the project reported here was to look for a possible quantitative difference in the protein and lipid components of the eggs as a result of specialized selection for high rate of lay and high egg weight. Furthermore, we looked for relations bettveen blood parameters, production parameters and egg composition traits. MaterialsTwo strains originating from the same basic population of highly productive hens \yere selected during two generations for high rate of lay (strain EN) and high egg weight (strain EW) respectively.The criterion used for selection for strain EN was the number of eggs laid from the first egg to the age of 40 weeks. For strain E W the criterion was egg weight at the age of 40 iveeks.In each strain 400 hens ivere tested in order to select 100 for breeding purposes. This selection was made on the basis of a n index which took into account information about the individual hen, her full-sibs and her half-sibs, iveighted in the optimal way. 100 males \\ere reared from each strain and 20 males \\ere selected from each of those groups for breeding purposes on the basis of the merits of their full sisters and half sisters. The effect of two generations of selection is reported in Table 1.Among the selected hens in the third generation 14 hens from each of the two strains were randomly chosen as a basis for the investigation of eggs and blood. For each of the hens a number of production parameters \vere determined including fertility and hatchability of 16 eggs pcr hen.The hens were fed on a market diet containing 11.29 MJ and l 3 y b crude protein. At the age of 52 \vceks 2 eggs were collected from each hen for investigation. The blood samples were taken at slaughter which occurred 5 days after egg collection and which was preceded by 18 hours' starvation before the blood sample was taken.The eggs \\ere stored for not more than 3 days before they were cooked and then the yolk and albumen \\ere separated and stored below -I 8 T . MethodsThe determination of protein in albumen and yolk were carried o u t by the Kjcldahl method using a Kjel-Foss Automatic apparatus, whcrcas protein in blood serum was determined by the biuret method as described by Kokot (1969). The protein fractions in blood serum were separated by means of acctat-cellulosc clectrophoresis on Millipore membrane with neckman Micro...

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Genetic parameter estimates and strain comparisons of egg compositional traits¹

Cited by 30 publications

References 7 publications

Genetic Relations between Reproduction, Chick Weight and Maternal Egg Composition in a White Leghorn Line

Genetic Relations between Reproduction, Chick Weight and Maternal Egg Composition in a White Leghorn Line

Composition of Eggs by Commercial Size Categories: Effects of Genetic Group, Age, and Diet

Lipids and Proteins in Eggs and Blood Serum from two Strains of Hens

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Genetic parameter estimates and strain comparisons of egg compositional traits1

Cited by 30 publications

References 7 publications

Genetic Relations between Reproduction, Chick Weight and Maternal Egg Composition in a White Leghorn Line

Genetic Relations between Reproduction, Chick Weight and Maternal Egg Composition in a White Leghorn Line

Composition of Eggs by Commercial Size Categories: Effects of Genetic Group, Age, and Diet

Lipids and Proteins in Eggs and Blood Serum from two Strains of Hens

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Product

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Genetic parameter estimates and strain comparisons of egg compositional traits¹