scholarly journals Genetic and Environmental Associations of Uncollectible Egg Production with Shell Quality, Rate of Lay, and Erratic Timing of Oviposition in White Leghorn Hens

1990 ◽  
Vol 69 (4) ◽  
pp. 509-516 ◽  
Author(s):  
W.M. MUIR ◽  
D.L. PATTERSON
Keyword(s):  
Egg Production ◽  
White Leghorn ◽  
Shell Quality

Influence of high calcium rearing diets, Christmas Island phosphate and ethylenediamine-tetraacetic acid on the laying performance of White Leghorn × Australorp hens

1977 ◽  
Vol 17 (89) ◽  
pp. 944
Author(s):  
H Karunajeewa
Keyword(s):  
Feed Intake ◽  
Egg Production ◽  
Daily Intake ◽  
White Leghorn ◽  
Feed Conversion ◽  
Shell Quality ◽  
Christmas Island ◽  
Laying Performance ◽  
High Calcium ◽  
Reduced Rate

White Leghorn x Australorp pullets were reared on diets with either low (0.91-1.12 per cent) or high (1.45-1.93 per cent) levels of calcium; in the laying phase pullets from each rearing regime were fed diets with either sterilized bone meal or Christmas Island phosphate as sources of supplemental phosphorus. Each of these layer diets was supplemented with 0, 300 or 500 p.p.m. of EDTA. The level of calcium in the rearing diets had no significant effect on liveweight, feed intake or mortality of the pullets during either the rearing or laying phases. High calcium starter and grower diets, however, reduced rate of lay by 2.1 per cent (P < 0.05) and efficiency of feed conversion by 3.7 per cent (P < 0.01). There was also a non-significant tendency to lower shell thickness. The inclusion of 2.5 per cent Christmas Island phosphate in the laying diet, resulting in a daily intake of 46 mg of fluorine per hen, decreased rate of lay by 2.2 per cent (P < 0.05), hen-housed egg production by 11 eggs (P < 0.05) and efficiency of feed conversion by 5.0 per cent (P < 0.01). The addition of 300 p.p.m. EDTA to the laying diet significantly (P < 0.01) improved efficiency of feed conversion by 4.7 per cent. Neither the source of phosphorus nor the dietary level of EDTA had any significant effects on liveweight, egg weight, feed intake, shell quality or mortality.

EFFECT OF DIETARY ENERGY AND CALCIUM LEVEL ON EGG PRODUCTION AND EGG QUALITY

1963 ◽  
Vol 43 (2) ◽  
pp. 337-343 ◽  
Author(s):  
T. M. MacIntyre ◽  
H. W. R. Chancey ◽  
E. E. Gardiner
Keyword(s):  
Adverse Effect ◽  
Specific Gravity ◽  
Calcium Intake ◽  
Egg Production ◽  
Egg Quality ◽  
Dietary Energy ◽  
White Leghorn ◽  
Shell Quality ◽  
Egg Shell ◽  
Single Comb

Two experiments were conducted with Single-Comb White Leghorn laying hens to measure some of the effects of energy and calcium levels on egg production and quality. In Experiment 1, rations containing 3.95 per cent calcium gave significantly higher egg production than rations containing 3.00 or 2.25 per cent, but in Experiment 2 there was no difference in egg production between rations containing 2, 3, 4, 5, and 6 per cent calcium. Rations containing 1.0 per cent calcium gave significantly lower egg production than rations containing 2.0 per cent or more. Levels of calcium up to 6.0 per cent had no adverse effect on egg production.Egg-shell quality as measured by specific gravity improved with increasing levels of calcium. A calcium intake of at least 4 grams per bird per day was necessary for best egg-shell quality.

Effect of Supplementation of Multi Enzymes on Production Performance and Egg Quality Traits in White Leghorn Layers

2016 ◽  
Vol 12 (2) ◽  
Author(s):  
C. Pandian ◽  
A. Sundaresan ◽  
A. V. Omprakash
Keyword(s):  
Egg Production ◽  
Egg Quality ◽  
Live Weight ◽  
Economic Benefits ◽  
Production Performance ◽  
Feed Consumption ◽  
Quality Traits ◽  
White Leghorn ◽  
Significant Difference ◽  
Enzyme Supplementation

The present study was conducted to assess the effect of supplementation of Multi-enzymes with lysophospholipids on production performance of pure line White Leghorn layers. Body weights before and after the experiment did not differ significantly across the experimental diets. Irrespective of the dietary treatments, the birds gained 3.83 per cent of live weight relative to its initial body weight. Mean per cent Hen housed egg production was significantly (Pis less than 0.05) higher in diet supplemented with 0.10 MEC-L than other groups. Mean egg weight and average daily feed consumption during 25 to 35 weeks of age indicated no significant effect of enzyme supplementation. Average daily feed consumption per bird in control, 0.05 % and 0.1% multi-enzyme supplemented groups was 108.13, 105.66 and 107.67 g respectively and birds offered control diet recorded numerically more feed intake than enzyme supplemented groups. Comparatively low feed per egg was observed in 0.10 per cent group followed by 0.05 per cent group which offers economic benefits than control diets. However, the egg quality traits between different dietary enzyme supplementation groups showed no significant difference.

scholarly journals Dual-Purpose Poultry in Organic Egg Production and Effects on Egg Quality Parameters

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 897
Author(s):  
Marianne Hammershøj ◽  
Gitte Hald Kristiansen ◽  
Sanna Steenfeldt
Keyword(s):  
Egg Production ◽  
Egg Quality ◽  
Quality Parameters ◽  
Egg Laying ◽  
High Yield ◽  
Meat Production ◽  
Dual Purpose ◽  
Shell Quality ◽  
Egg Shell ◽  
Genotype A

Egg laying genotypes have been selected for generations due to their high yield and egg quality, resulting in efficient feed utilization and low body weight; hence, they are not suitable for meat production. This imposes an issue for the male layer chicks, which are killed at one day old. Because of ethical and food waste concerns, the search for suitable dual-purpose genotypes in order to avoid euthanasia of male day-old chicks has intensified. The aim of the present study is to evaluate potential dual-purpose genotypes for their egg quality compared to a representative egg laying genotype. Three dual-purpose genotypes with divergent characteristics were evaluated: genotype A represented an experimental crossbreed based on a broiler type male and an egg layer female, genotype B was a pure breed, and genotype C was a crossbreed of a layer type. These were compared to a control genotype D, which was an egg layer. Eggs were collected six times during the period of 21–54 weeks of hen age, i.e., a total of 1080 shell eggs were analyzed. Examined parameters were weights of egg, shell, yolk, and albumen, by calculating their relative proportions. Shell quality was assessed by shell strength, shell stiffness, and shell thickness. Yolk quality was determined as yolk color and inclusions of blood and meat spots, and albumen quality was evaluated in terms of pH and dry matter (DM) content. The egg layer genotype produced the smallest eggs with least blood and meat spot inclusions compared to that produced by the three dual-purpose genotypes. Shell quality was superior for the layer genotype. However, the experimental genotype A laid eggs of comparable shell quality, albumen DM, and yolk weight, but also with the darkest and most red-yellow colored yolk. The two other dual-purpose genotypes produced eggs of low-medium quality. In conclusion, the genotype A could serve as dual-purpose genotype from an egg quality perspective.

scholarly journals Bayesian inference of genetic parameters for reproductive and performance traits in White Leghorn hens

2018 ◽  
Vol 63 (No. 6) ◽  
pp. 230-236 ◽  
Author(s):  
J.O. Rosa ◽  
G.C. Venturini ◽  
T.C.S. Chud ◽  
B.C. Pires ◽  
M.E. Buzanskas ◽  
...  
Keyword(s):  
Bayesian Inference ◽  
Fixed Effects ◽  
Egg Production ◽  
Genetic Parameters ◽  
Laying Hens ◽  
Reproductive Traits ◽  
A Posteriori ◽  
White Leghorn ◽  
Performance Traits ◽  
And Performance

This study estimated the genetic parameters for reproductive and performance traits and determined which ones can be used as selection criteria for egg production in laying hens using the Bayesian inference. The data of 1894 animals from three generations of White Leghorn laying hens were analyzed for fertility (FERT), hatchability (HATC), and birth rate measurements at 60 weeks of age (BIRTH), body weight at 16 and 60 weeks of age (BW16 and BW60), age at sexual maturity (ASM), egg height/width ratio, weight, and density at 28, 36, and 40 weeks of age (RHW28, RHW36, RHW40, WEGG28, WEGG36, WEGG40, DENS28, DENS36, and DENS40, respectively) traits. The genetic parameters were estimated by the Bayesian inference method of multi-trait animal model. The model included the additive and residual genetic random effects and the fixed effects of generation. The a posteriori mean distributions of the heritability estimates for reproductive traits ranged from 0.14 ± 0.003 (HATC) to 0.22 ± 0.005 (FERT) and performance from 0.07 ± 0.001 (RHW28) to 0.42 ± 0.001 (WEGG40). The a posteriori mean distributions of the genetic correlation between reproductive traits ranged from 0.18 ± 0.026 (FERT and HACT) to 0.79 ± 0.007 (FERT and BIRTH) and those related to performance ranged from –0.49 ± 0.001 (WEGG36 and DENS36) to 0.75 ± 0.003 (DENS28 and DENS36). Reproductive and performance traits showed enough additive genetic variability to respond to selection, except for RHW28. This trait alone would have little impact on the genetic gain because environmental factors would have a higher impact compared to those from the additive genetic factors. Based on the results of this study, the selection applied on the BIRTH trait can be indicated to improve FERT and HATC of eggs. Furthermore, the use of the WEGG40 could improve egg quality in this population.

scholarly journals Genetic Analysis of a White Leghorn Closed Flock Apparently Plateaued for Egg Production

1958 ◽  
Vol 37 (3) ◽  
pp. 565-580 ◽  
Author(s):  
Yukio Yamada ◽  
B.B. Bohren ◽  
L.B. Crittenden
Keyword(s):  
Genetic Analysis ◽  
Egg Production ◽  
White Leghorn

Breeding

1937 ◽  
Vol 10 (4) ◽  
pp. 247-258 ◽  
Keyword(s):  
Egg Production ◽  
Average Weight ◽  
List Type ◽  
Type Number ◽  
White Leghorn ◽  
Egg Weight ◽  
Average Production ◽  
The Way

1.The connection between the rate of maturity (number of days between birth and production of the first egg) and egg production of 938 White Leghorn pullets, hatched and reared on the Experimental farm of the Oliefabrieken Calvé-Delft was investigated. The pullets were of various strains and received widely differing treatment as regards feeding.2.There is a curvilinear correlation between rate of maturity and to talproduction and also between rate of maturity and winter production. It is, therefore, not correct to calculate with rectilinear correlations or regressions.3.The conditions, obtaining during the rearing, influence not only the rate of maturity, but also the connection between the rate of maturity and egg production.4.It is, therefore, impossible to state any generally acceptable rules concerning the way in which the existing connection can be used to raise the average production by the elimination of certain birds.5.Even when the pullets have been carefully culled either before or at the commencement of production, it is possible to raise the average production still further by eliminating those birds, which come into production last. A considerable number of bad producers are found among the birds with the slowest rate of maturity.6.No connection was found between rate of maturity and mortality.7.Neither was there any connection between rate of nlaturity and the average weight of the eggs produced after December.8.For the 514 birds which began production after 30th September, 1935, a rectilinear correlation of +0.66±0.02 was found between rate of maturity and the average weight of the first ten eggs produced. The regression-eo-efficient of this “inception egg-weight” to rate of maturity in +0.16±0.02.

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