Relationship between Delayed Onset of Egg Production and Involution of the Bursa of Fabricius in White Leghorn Chickens

1989 ◽  
Vol 33 (2) ◽  
pp. 361 ◽  
Author(s):  
G. D. Butcher ◽  
R. H. Harms ◽  
R. W. Winterfield
Keyword(s):  
Egg Production ◽  
Bursa Of Fabricius ◽  
White Leghorn ◽  
Delayed Onset

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 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.

scholarly journals Influencia del hidrolizado de proteínas en el comportamiento bioproductivo en gallinas de la línea L1 White Leghorn

2018 ◽  
Vol 65 (2) ◽  
Author(s):  
Manuel Colas ◽  
Edmundo Oliver Pérez ◽  
Yanet Támbara
Keyword(s):  
Food Intake ◽  
Quality Indicators ◽  
Feed Intake ◽  
Egg Production ◽  
Nutritional Supplement ◽  
Protein Hydrolysates ◽  
Egg Laying ◽  
White Leghorn ◽  
Light Line ◽  
Mass Conversion

The objective of this study was to evaluate the influence of protein hydrolysates (PH), as a nutritional supplement, in the bioproduction performance of White Leghorn hens. Thirty-nine-week old light line hens were assessed during six weeks. Two treatments (T) were designed involving 320 hens each (three replications of 40 hens each). In T1, each bird received 2 ml of PH daily; the birds in T2 were not offered the product. The following variables were controlled: bioproduction (total egg production, egg-laying percentage, total feed intake, mass conversion, viability, and caused mortality); incubation indicators (eggs to plant, incubation percentage, hatchability, and top quality chicks) and; quality (feed intake by top quality chicks, and top quality chicks per hen). The hens that received the PH showed significant differences in the laying, incubation, and hatchability percentage, as well as mass conversion, and the egg to plant ratio. They showed better performance in quality indicators. It is concluded that the use of PH in light line hens improves their bioproduction performance, as well as the indicators of to incubation, egg to plant ratio, and hatchability; its use also reduces by approximately 100 grams the necessary food intake to obtain top quality chicks.

scholarly journals DOMINANCE AND EPISTASIS IN HETEROSIS OF WHITE LEGHORN STRAIN CROSSES

1987 ◽  
Vol 67 (3) ◽  
pp. 663-680 ◽  
Author(s):  
R. W. FAIRFULL ◽  
R. S. GOWE ◽  
J. NAGAI
Keyword(s):  
Body Weight ◽  
Sexual Maturity ◽  
Egg Production ◽  
Significant Contribution ◽  
Production Traits ◽  
White Leghorn ◽  
Cross Combination ◽  
Commercial Strain ◽  
Better Than

Four unrelated pure strains of White Leghorns including a grandparent strain from industry and 12 two-strain, 24 three-strain, 24 four-strain and 12 F2 strain crosses produced contemporaneously were used to examine the role of dominance and epistasis in heterosis. A control strain and a commercial strain were also included. For egg weight, the heterosis observed closely approximated that expected due to dominance alone. For sexual maturity and body weight, dominance was the major component of heterosis, but epistasis made a significant contribution — additive by additive (A × A) genetic effects for sexual maturity and 140-d body weight, and parental epistasis for mature body weight. Both dominance and epistasis played a significant role in heterosis for egg production traits. A × A, dominance by dominance (D × D) and additive by dominance (A × D) epistasis were all important for hen-housed egg production and hen-housed egg yield. For hen-day rate of egg production, A × A epistasis was significant only early in the laying year (to 273 d), A × D and D × D were significant to 385 d and in the full year (to 497 d); however, none (A × A, A × D and D × D) was significant near the end of lay (386–497 d). Overall heterosis estimates for full year egg production measured as hen-housed egg production to 497 d or hen-day rate from housing to 497 d clearly showed that on average two-strain crosses were superior to three-strain crosses which were superior to four-strain crosses which in turn exceeded the F2 crosses. Nevertheless, several three-strain crosses had performance for egg production that was equal to or better than the two-strain cross with the highest egg production. Thus, in commerce, where the level of egg production is of great economic importance, the testing and use of a specific three-way cross combination will usually result in a better commercial product. Key words: Heterosis, egg production genetics, epistasis, stocking rate, strain cross, White Leghorn

scholarly journals Subchronic Acephate Exposure Induces Immunotoxicity in White Leghorn Cockerels

2021 ◽  
Author(s):  
Syamantak Tripathi ◽  
Prem Govindappa ◽  
Megha Bedekar ◽  
Yash Sahni ◽  
B. Sarkhel ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Body Weight Gain ◽  
Animal Health ◽  
Acetylcholinesterase Activity ◽  
Bursa Of Fabricius ◽  
Delayed Type Hypersensitivity ◽  
White Leghorn ◽  
Groundnut Oil ◽  
Con A ◽  
Live Body Weight

Abstract We investigated the subchronic immunotoxicity of the phosphoramidothioate organophosphorous insecticide, acephate in white leghorn cockerels (WLH). The cockerels were divided into five groups; C1 (plain control), C2 (vehicle control), T1, T2, and T3 which received acephate suspended groundnut oil for 60 days at doses of 21.3, 28.4 and 42.6 mgkg−1respectively. The live body weight gain, absolute and relative weights of the spleen, thymus, and bursa of Fabricius, hemoglobin (Hb), total erythrocyte counts (TEC), packed cell volume (PCV) and lymphocytes were significantly decreased. However, monocytes, eosinophils, heterophils, and basophils were significantly increased. Total protein, albumin and albumin to globin ratio, the antibody response to RD-F and delayed-type hypersensitivity response to DNCB dye or PHA-P, erythrocyte and brain Acetylcholinesterase activity was also significantly reduced in T2 and T3. At 40 and 60 days of acephate exposure, nitrate and nitric oxide production by RD-F and mitogen Con A stimulated peripheral blood and splenic lymphocytes, as well as lymphocyte proliferation in response to antigen RD-F and mitogen Con A stimulation, were significantly decreased in groups T2 and T3. Furthermore, dose-dependent increases in the frequency of micronuclei formation, varying intensity serum protein bands with different protein fractions (14.85KDa), and splenic DNA laddering (180 bp) were observed in groups T2 and T3. Histopathologically, the spleen and bursa showed morphological changes and mild lymphocyte depletion. In conclusion, low-level acephate exposure may affect acetylcholinesterase, lymphocytes, and immune responses in cockerels. As a result, it should be considered when assessing immunotoxicity and the risk to human and animal health.

scholarly journals A production trial with layers of four hybrids under different environmental conditions in the Eastern Province of Saudi Arabia.

1971 ◽  
Vol 19 (4) ◽  
pp. 204-210
Author(s):  
H. Appelman ◽  
B.J. Bonhof
Keyword(s):  
Saudi Arabia ◽  
Rhode Island ◽  
New Hampshire ◽  
Egg Production ◽  
Live Weight ◽  
Egg Mass ◽  
White Leghorn ◽  
Eastern Province ◽  
Egg Weight ◽  
Food Consumed

161 Australorp X Rhode Island Red (RIR) X New Hampshire (NH) and 166 White Leghorn (WL) imported fowls were kept in insulated housing; 161 Australorp X RIR X NH, 166 WL, 154 RIR X WL and 148 RIR X NH X RIR fowls were kept in open houses. In the 6 groups resp., live weight at 126 days of age averaged 1602, 1227, 1578, 1234, 1397 and 1539 g, food consumption 4.02, 4.49, 4.03, 4.47, 4.25 and 4.17 kg/kg gain, overall laying percentage 56.6, 56.4, 52.5, 53.4, 55.0 and 37.5, egg production/hen 202, 201, 188, 191, 196 and 134, and egg weight 56.3, 56.3, 55.0, 55.8, 55.0 and 57.5 g. Egg mass averaged 1335, 1323, 1191, 1151, 1126 and 796 kg and food consumed/kg eggs produced 3.68, 3.53, 3.71, 3.25, 3.37 and 4.74 kg. Live weight at 16 mth of age averaged 2894, 2040, 2665, 1874, 2132 and 2517 g, and mortality 12.8, 11.1, 33.6, 43.5, 52.8 and 50.4%. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Subchronic Acephate Exposure Induces Immunotoxicity in White Leghorn Cockerels

2021 ◽  
Author(s):  
Syamantak Mani Tripathi ◽  
Prem Kumar Govindappa ◽  
Megha Kadam Bedekar ◽  
Yash Pal Sahni ◽  
B. C. Sarkhel ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Body Weight Gain ◽  
Animal Health ◽  
Acetylcholinesterase Activity ◽  
Bursa Of Fabricius ◽  
Delayed Type Hypersensitivity ◽  
White Leghorn ◽  
Groundnut Oil ◽  
Con A ◽  
Live Body Weight

Abstract We investigated the subchronic immunotoxicity of the phosphoramidothioate organophosphorous insecticide, acephate in white leghorn cockerels (WLH). The cockerels were divided into five groups; C1 (plain control), C2 (vehicle control), T1, T2, and T3 which received acephate suspended groundnut oil for 60 days at doses of 21.3, 28.4 and 42.6 mgkg− 1respectively. The live body weight gain, absolute and relative weights of the spleen, thymus, and bursa of Fabricius, hemoglobin (Hb), total erythrocyte counts (TEC), packed cell volume (PCV) and lymphocytes were significantly decreased. However, monocytes, eosinophils, heterophils, and basophils were significantly increased. Total protein, albumin and albumin to globin ratio, the antibody response to RD-F and delayed-type hypersensitivity response to DNCB dye or PHA-P, erythrocyte and brain Acetylcholinesterase activity was also significantly reduced in T2 and T3. At 40 and 60 days of acephate exposure, nitrate and nitric oxide production by RD-F and mitogen Con A stimulated peripheral blood and splenic lymphocytes, as well as lymphocyte proliferation in response to antigen RD-F and mitogen Con A stimulation, were significantly decreased in groups T2 and T3. Furthermore, dose-dependent increases in the frequency of micronuclei formation, varying intensity serum protein bands with different protein fractions (14.85KDa), and splenic DNA laddering (180 bp) were observed in groups T2 and T3. Histopathologically, the spleen and bursa showed morphological changes and mild lymphocyte depletion. In conclusion, low-level acephate exposure may affect acetylcholinesterase, lymphocytes, and immune responses in cockerels. As a result, it should be considered when assessing immunotoxicity and the risk to human and animal health.

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