Effects of divergent selection for growth on egg quality traits in Japanese quail

2016 ◽  
Vol 56 (11) ◽  
pp. 1797 ◽  
Author(s):  
Mohammed A. F. Nasr ◽  
Mahmoud S. El-Tarabany ◽  
Michael J. Toscano
Keyword(s):  
Body Mass ◽  
Japanese Quail ◽  
Egg Quality ◽  
Control Line ◽  
Quality Traits ◽  
Shell Weight ◽  
External Shell ◽  
Selection For ◽  
And Control ◽  
The Impact

The experiment was designed to investigate the impact of selection for increased body mass on external and internal egg quality traits of Japanese quail. Three hundred and sixty Japanese quail, divergently selected over three generations for different body mass at 4 weeks of age, were used. Quail were homogeneously divided into three groups each consisting of 120 birds: high body mass (HBM), low body mass (LBM) and Control. ANOVA was used to detect the effect of selection on egg quality. In addition, correlation between external and internal egg quality traits was measured. Our results revealed that HBM quail laid heavier eggs (P = 0.03 compared with LBM but not significantly different with Control quail) with a higher external (shell thickness, shell weight, eggshell ratio and eggshell density, P = 0.0001) and internal egg quality score (albumen weight, P = 0.003; albumen ratio, P = 0.01; albumen height, yolk height, yolk index and Haugh unit, P = 0.0001) when compared with both the Control and LBM. The egg surface area and yolk diameter were significantly higher in HBM when compared with the LBM but not with the Control line. Egg weight was positively correlated with albumen weight (r = 0.54, P = 0.0001), albumen ratio (r = 0.14, P = 0.05), yolk height (r = 0.27, P = 0.0001), yolk weight (r = 0.23, P = 0.002), yolk diameter (r = 0.14, P = 0.05) and yolk index (r = 0.21, P = 0.005) but was negatively correlated with yolk ratio (r = –0.16, P = 0.03). Our results indicate that selection for higher body mass might result in heavier eggs and superior egg quality.

scholarly journals Influence of selection for egg production on egg quality traits in Japanese quail

2021 ◽  
Vol 51 (1) ◽  
Author(s):  
Mahmoud M. El-Attrouny ◽  
Mahmoud M. Iraqi
Keyword(s):  
Japanese Quail ◽  
Egg Production ◽  
Egg Quality ◽  
Genetic Correlations ◽  
Selection Response ◽  
Egg Laying ◽  
Internal Quality ◽  
Correlated Response ◽  
Quality Traits ◽  
Selection For

The current study investigated the influence of selection for increased egg production on external and internal egg quality traits over five generations in Japanese quail. A total of 4325 fresh eggs from 1326 females were collected each week during the egg-laying period to estimate heritability, genetic and phenotypic correlations, and correlated response of external and internal egg quality traits to selection for egg number (EN). The direct response to selection indicated an increase of 7.7 ± 0.27 eggs produced during the 90 days following production of the first egg. The correlated responses to selection indicated that selection for higher EN can be expected to increase EW and increase egg quality. Estimates of heritability ranged from 0. 11 to 0.35 for external egg quality traits and from 0.08 to 0.32 for internal egg quality traits. Estimates of the genetic correlations of EN with external and internal traits were positive, ranging from 0.09 to 0.25 and from 0.02 to 0.27, respectively. These estimates indicated few if any genetic antagonisms that would adversely affect selection response. However, eggshell thickness would not be expected to change as a result of selection for EN. Thus, the external and internal quality of Japanese quail eggs could be improved by selection for high egg production.

Effect of selection for increased litter size on ovulation rate and embryo survival in sheep

1990 ◽  
Vol 1990 ◽  
pp. 32-32 ◽  
Author(s):  
J.P. Hanrahan
Keyword(s):  
Litter Size ◽  
Ovulation Rate ◽  
Control Line ◽  
Selection Experiment ◽  
Embryo Survival ◽  
Relative Contribution ◽  
Variation Data ◽  
Component Traits ◽  
Selection For ◽  
The Impact

Variation in litter size in sheep is essentially attributable to variation in ovulation rate and embryo survival. Genetic variation in litter size, both among and within breeds, is largely attributable to variation in ovulation rate. While there is evidence for genetic differences among breeds in embryo survival the contribution of this component to within breed variation appears to be minor (Hanrahan, 1982). The impact of selection based on litter size on its component traits should reflect the relative contribution of these components to within breed variation. Data from two lines of Galway sheep, a Control line and one selected for increased prolificacy (Hanrahan and Timon, 1978), have been used to provide evidence on this point.Details relating to the selection experiment which provided the data for the present study are in Hanrahan (1984). Briefly a flock of Galway sheep was assembled from industry sources (both pedigree and non-pedigree) between 1963 and 1965.

CORRELATED RESPONSES IN EGG QUALITY TRAITS TO SELECTION FOR EARLY BODY WEIGHT IN MEAT-TYPE CHICKENS

1972 ◽  
Vol 14 (3) ◽  
pp. 477-482 ◽  
Author(s):  
V. Buvanendran ◽  
E. S. Merritt
Keyword(s):  
Body Weight ◽  
Egg Quality ◽  
Correlated Response ◽  
Quality Traits ◽  
Correlated Responses ◽  
Egg Weight ◽  
Shell Color ◽  
Blood Spots ◽  
Selection For ◽  
Meat Type

The correlated responses in egg quality traits to selection for high early body weight were studied in seven meat-type populations comprising five selected and two control lines. Traits studied were specific gravity, egg weight, albumen height, Haugh units, shell color, egg shape, shell roughness, wrinkling and asymmetry, and incidence of blood spots, meat spots and double yolks. Significant (P < 0.05 or < 0.01) correlated changes, as determined by the regression of correlated response (egg quality traits) on primary response (body weight), were obtained for egg weight, albumen height, Haugh units, asymmetry of shell and blood spots. All but blood spots increased with selection for high body weight. Shell color showed a consistent trend towards a darker color with increasing body weight. Scores for roughness of shell and, with one minor exception, the incidence of double yolks, also showed consistent trends (positive) with increasing body weight. Estimates of genetic correlations, derived directly from intra-line genetic analyses of the six pedigreed populations in the experiment, were in most cases in reasonable agreement with realized estimates.

scholarly journals The Response of Layer Hen Productivity and Egg Quality to an Additional Limestone Source when Offered Diets Differing in Calcium Concentrations and the Inclusion of Phytase

Animals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2991
Author(s):  
Isabelle Ruhnke ◽  
Yeasmin Akter ◽  
Terence Zimazile Sibanda ◽  
Aaron J. Cowieson ◽  
Stuart Wilkinson ◽  
...  
Keyword(s):  
Egg Production ◽  
Laying Hens ◽  
Egg Quality ◽  
Nutrient Digestibility ◽  
Egg Mass ◽  
Shell Weight ◽  
Shell Quality ◽  
Ad Libitum ◽  
Egg Shell ◽  
The Impact

Laying hens require substantial quantities of calcium (Ca) to maintain egg production. However, maintaining recommended dietary Ca through inclusion of limestone may impede nutrient digestibility, including that of other minerals. It was hypothesized that providing a separate source of dietary Ca in the form of limestone grit would preserve Ca intake of hens offered diets containing suboptimal Ca concentrations. Furthermore, the impact of dietary phytase at a “superdosing” inclusion rate on the voluntary consumption of limestone grit was evaluated. One hundred and forty-four laying hens (19 weeks of age) were assigned to one of six dietary treatments in a 3 × 2 factorial arrangement comprising three dietary Ca concentrations (40, 30, and 20 g/kg) and ±dietary phytase (3500 FYT/kg diet) on an ad libitum basis for six weeks. Limestone grit (3.4 ± 1.0 mm) was provided to all hens ad libitum. Hens offered diets containing phytase consumed significantly less limestone grit p = 0.024). Egg weight, rate of lay, and egg mass were unaffected by dietary treatment (p > 0.05). Egg shell weight % (p < 0.001), shell thickness (p < 0.001), and shell breaking strength (p < 0.01) decreased in line with dietary Ca levels. In summary, dietary superdosing with phytase reduced the consumption of a separate limestone source in individually housed, early lay ISA Brown hens. Egg shell quality variables but not egg production worsened in line with lower dietary Ca levels.

scholarly journals Changes in egg quality traits associated with long-term selection for lower yolk cholesterol content in Japanese quail

2008 ◽  
Vol 53 (No. 3) ◽  
pp. 119-127 ◽  
Author(s):  
J. Baumgartner ◽  
Z. Končeková ◽  
J. Benková ◽  
D. Peškovičová ◽  
J. Simenovová ◽  
...  
Keyword(s):  
Egg Quality ◽  
Shape Index ◽  
Cholesterol Content ◽  
Quality Traits ◽  
Egg Weight ◽  
Term Selection ◽  
Edible Part ◽  
Selection For ◽  
Yolk Cholesterol

In the present paper we describe the basic results of long-term selection for low yolk cholesterol content in Japanese quail and its influence on development and relationship with other egg quality traits during nineteen selected generations. The changes in a selected low cholesterol line were compared with changes in an unselected control line to obtain the real selection response to estimated traits. There was a significant decrease in yolk cholesterol content from 1 815 mg/100 g of fresh yolk (P generation) to 1 522 mg/100 g yolk (S19 generation). According to the value of regression coefficient <I>b</I> the decrease per one generation was 15.71 mg/100 g yolk. The decrease in cholesterol of the edible part of egg was also effective and it significantly decreased by 11.29 mg/100 g of the edible part of egg in each generation. There were only insignificant changes in egg weight, but we found a significant increase in yolk weight during selected generations. According to the regression analysis the increase in yolk weight was 0.019 mg/100 g per one generation. There were a positive but insignificant increase also in albumen weight, shell weight and weight of the edible part of egg. We found a small and insignificant decrease in shape index. We determined very high and significant positive correlations between cholesterol content in yolk and cholesterol content in the edible part of egg (0.801+++) and significant negative correlations between yolk cholesterol content and egg weight (–0.515+), yolk weight (–0.468+) and weight of the edible part of egg (–0.475). There were only low, positive and insignificant correlations between yolk cholesterol content and yolk egg proportion and egg shape index.

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