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 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.

scholarly journals REPEATABILITY OF EGG NUMBER AND EGG QUALITY TRAITS IN COMMERCIAL PULLETS

2021 ◽  
Vol 21 ◽  
pp. 71-75
Author(s):  
J. C. Okonkwo ◽  
S. N. Ibe
Keyword(s):  
Genetic Gain ◽  
Shell Thickness ◽  
Egg Quality ◽  
Shape Index ◽  
Quality Traits ◽  
Egg Weight ◽  
Egg Number ◽  
Selection For ◽  
Haugh Unit

Repeatability estimates of 0.09 for egg number to 30 weeks of age; 0.67, 0.53, 0.51 0.20 and 0.26 for egg weight (EW), shell thickness (ST), Haugh unit (HU), yolk index (YI) and shape index (SI), respectively, at 22 weeks of age; and 0.85, 0.78, 0.82, 0.49 and 0.62 for the same traits, respectively at 30 weeks of age were obtained in a flock of exotic commercial pullets reared in cages. The expected relative genetic gain per generation of selection for repeated records was inversely related to the magnitude of repeatability. Thus, as laying progressed, repeatability estimates became higher and expected genetic gain from using additional records decreased and fewer records were required to characterize the pullets for inherent transmitting ability. While 4 eggs per hen areconsidered adequate for 22 - week EW, ST and HU, 8 eggs are required for YI and ŞI. The considered numbers of eggs for corresponding traits at 30 weeks are 3 and 4, respectively. Measurements on 10 eggs per hen are required for egg number to 30 weeks.

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.

Correlated response to selection for litter size in pigs: II. Carcass, meat, and fat quality traits

2002 ◽  
Vol 80 (10) ◽  
pp. 2566 ◽  
Author(s):  
J. Estany ◽  
D. Villalba ◽  
M. Tor ◽  
D. Cubiló ◽  
J. L. Noguera
Keyword(s):  
Litter Size ◽  
Correlated Response ◽  
Quality Traits ◽  
Response To Selection ◽  
Fat Quality ◽  
Selection For

Selection for lean growth rate and correlated responses in litter traits in a synthetic line of Yorkshire-Meishan pigs

2001 ◽  
Vol 81 (2) ◽  
pp. 205-214 ◽  
Author(s):  
P. Chen ◽  
T. J. Baas ◽  
J. C. M. Dekkers ◽  
L. L. Christian
Keyword(s):  
Growth Rate ◽  
Regression Coefficients ◽  
Correlated Response ◽  
Selection Line ◽  
Control Line ◽  
Correlated Responses ◽  
Lean Growth ◽  
Litter Traits ◽  
Selection For ◽  
Synthetic Line

Selection for lean growth rate (LGR) was conducted for four generations in a synthetic line of Yorkshire-Meishan pigs to study the effectiveness of selection for LGR and correlated responses in litter traits. Lean growth rate was estimated from ultrasound measurements of 10th-rib backfat thickness and longissimus muscle area. In the selection line, 7 boars and 20 gilts with the highest LGR were selected to produce the next generation. The generation interval was 13 mo and the average selection differential per generation was 1.1 phenotypic standard deviation units. A contemporaneous control line was maintained by randomly selecting 5 boars and 15 gilts. Data from a total of 1057 pigs sired by 58 boars and out of 133 sows were available from the two lines. Selection responses were estimated from deviations of the selection line from the control line using least squares (LS) and by multiple trait derivative-free restricted maximum likelihood analysis using an animal model (AM). The estimate of response to selection per generation using LS was 9.4 ± 0.95 g d–1 for LGR. The corresponding estimate from the AM was 9.8 ± 0.51 g d–1. Correlated responses in litter traits were regressed on generation. For the LS method, regression coefficients were negative but not significant (P > 0.05) for total number born, number born alive, and number at 21 d and at 42 d. Significant, positive correlated responses occurred in 42-d litter weight and 21-d piglet weight (P < 0.05). For the AM method, the regression coefficients were also negative, but were not significant (P > 0.05) for numberalive at birth, at 21 d, and at 42 d. A significant positive correlated response occurred only for 42-d litter weight (P < 0.05). Although results are based on a population of limited size, it can be concluded that selection for LGR in a synthetic line is effective and should have little effect on litter traits. Key words: Pigs, selection, lean growth rate, correlated response

scholarly journals Correlated Response on Growth Traits and Their Variabilities to Selection for Ovulation Rate in Rabbits Using Genetic Trends and a Cryopreserved Control Population

Animals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2591
Author(s):  
Rosa Peiró ◽  
Celia Quirino ◽  
Agustín Blasco ◽  
María Antonia Santacreu
Keyword(s):  
Growth Traits ◽  
Ovulation Rate ◽  
Control Population ◽  
Individual Growth ◽  
Correlated Response ◽  
Phenotypic Variance ◽  
Correlated Responses ◽  
Growth Variability ◽  
Selection For ◽  
Genetic Trends

The aim of this work was to estimate correlated responses in growth traits and their variabilities in an experiment of selection for ovulation rate during 10 generations in rabbits. Individual weight at 28 days old (IW28, kg) and at 63 days old (IW63, kg) was analyzed, as well as individual growth rate (IGR = IW63 − IW28, kg). The variability of each growth trait was calculated as the absolute value of the difference between the individual value and the mean value of their litter. Data were analyzed using Bayesian methodology. The estimated heritabilities of IW28, IW63 and IGR were low, whereas negligible heritabilities were obtained for growth variability traits. The common litter effect was high for all growth traits, around 30% of the phenotypic variance, whereas low maternal effect for all growth traits was obtained. Low genetic correlations between ovulation rate and growth traits were found, and also between ovulation rate and the variability of growth traits. Therefore, genetic trends methods did not show correlated responses in growth traits. A similar result was also obtained using a cryopreserved control population.

scholarly journals The Effect of the Type of Alternative Housing System, Genotype and Age of Laying Hens on Egg Quality

2018 ◽  
Vol 18 (2) ◽  
pp. 541-556 ◽  
Author(s):  
Zofia Sokołowicz ◽  
Józefa Krawczyk ◽  
Magdalena Dykiel
Keyword(s):  
Laying Hens ◽  
Egg Quality ◽  
Housing System ◽  
Color Intensity ◽  
Egg Weight ◽  
Blood Spots ◽  
Alternative Housing ◽  
Housing Systems ◽  
System Type ◽  
Eggshell Color

Abstract The present study investigated the effect of the type of alternative housing system, and genotype and age of laying hens on physical traits of egg shell and contents. It was demonstrated that alternative housing system type influenced egg weight and shape, and eggshell color and yolk color intensity. Eggs from free-range system were heavier and were characterized by more intense yolk color. No effect of alternative housing system type on albumen height, value of Haugh units (HU value) and presence of meat and blood spots was noted. Hen genotype had a significant effect on egg weight and eggshell color intensity in each of the alternative housing systems tested in this study. Hy-line Brown hens laid heavier eggs than hens of native breeds. Genotype was also observed to affect egg content traits (albumen height, HU values and presence of meat and blood spots). Independently of the type of alternative housing system, most blood and meat spots were noted in eggs of hens laying brown-shelled eggs, i.e. R-11 and Hy-line Brown layers. Laying hen age significantly impacted on egg weight, yolk percentage, eggshell traits (color intensity, weight, thickness and strength) and egg content traits (HU value, yolk weight and color intensity, presence of meat and blood spots). Older hens laid heavier eggs with a greater yolk percentage but with thinner eggshell.

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