scholarly journals The Effects of the Northern Fowl Mite, Ornithonyssus sylivarium on Egg Production and Body Weight of Caged White Leghorn Hens

1979 ◽  
Vol 58 (1) ◽  
pp. 191-194 ◽  
Author(s):  
JOYCE A. DeVANEY
Keyword(s):  
Body Weight ◽  
Egg Production ◽  
White Leghorn ◽  
Northern Fowl Mite

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

SUBSTITUTION OF SORGHUM FOR WHEAT IN DIETS FOR LAYING HENS

1982 ◽  
Vol 62 (1) ◽  
pp. 305-306 ◽  
Author(s):  
E. E. GARDINER ◽  
D. J. MAJOR ◽  
S. DUBETZ
Keyword(s):  
Body Weight ◽  
Key Words ◽  
Egg Production ◽  
Laying Hens ◽  
Feed Consumption ◽  
White Leghorn ◽  
Egg Weight ◽  
Single Comb

The effects of substituting various levels of sorghum for wheat in diets for laying hens were studied. Egg production, egg weight, feed consumption, body weight and hatchability of eggs from Single Comb White Leghorn hens were not affected by the proportion of sorghum in the diet. Key words: Sorghum, wheat, nutrition, egg production

Body Weight and Egg Production Performance of Induced Moulted White Leghorn Layers

2006 ◽  
Vol 5 (10) ◽  
pp. 996-1000
Author(s):  
P. Thirunavukkarasu . ◽  
M. Moorthy . ◽  
K. Viswanathan .
Keyword(s):  
Body Weight ◽  
Egg Production ◽  
Production Performance ◽  
White Leghorn

Upgrading the indigenous poultry of Uganda IV. Egg production

1963 ◽  
Vol 60 (2) ◽  
pp. 225-227
Author(s):  
J. C. M. Trail
Keyword(s):  
Body Weight ◽  
Production Rate ◽  
Rhode Island ◽  
Food Consumption ◽  
Egg Production ◽  
White Leghorn ◽  
Egg Weight ◽  
Body Weights ◽  
The Cross ◽  
Egg Production Rate

Data on egg production, egg weight, food consumption, broodiness, mortality and body weights of the progeny of indigenous poultry of Uganda crossed with Light Sussex, White Leghorn, Rhode Island Red and Black Australorp breeds were collected collected over the 25-week period from 161 to 336 days of age and compared with the performances of indigenous poultry.In comparison with the indigenous birds, the cross-breeds had a 61% higher mean egg production rate, a 34% lower food consumption per pound of eggs produced, a 15% higher egg weight, a 30% reduction in mortality, a 23% increase in body weight and a decrease in broodiness.All the cross-breeds were superior in productive respects to the indigenous birds and the White Leghorn and Light Sussex breeds appeared to be the best for use in the upgrading of indigenous stock for highest egg production results.

scholarly journals The Effect of Meal-Eating on Egg Production and Body Weight of White Leghorn Chickens

1972 ◽  
Vol 51 (4) ◽  
pp. 1109-1118 ◽  
Author(s):  
D. Polin ◽  
J.H. Wolford
Keyword(s):  
Body Weight ◽  
Egg Production ◽  
White Leghorn

scholarly journals Synthesis of stocks and phenotypic effects of dwarf and bantam sex-linked major genes in egg-type chickens

1997 ◽  
Vol 20 (3) ◽  
pp. 371-376
Author(s):  
Randolfo William Silvestre Custódio
Keyword(s):  
Body Weight ◽  
Sexual Maturity ◽  
Egg Production ◽  
Egg Laying ◽  
White Leghorn ◽  
Major Genes ◽  
Adult Body ◽  
Adult Body Weight ◽  
The Difference

The present study describes the production of stocks segregating dwarf (dw), bantam (dwB) and normal (dw+) alleles, as well as the characters, shank length, adult body weight, age at sexual maturity and egg production. Heterozygous K dw+/k dwB sires were mated to normal (dw+) dams to produce stock D6.a, and mated to dwB females to produce stock D6.b. Stock D4.a came from mating F1 heterozygous dwB dw sires to dwarf Leghorns. In a third series of matings, 7/8 Sebright and 1/8 dw-Leghorn dwB dw sires were crossed to three groups of dams of different genotypes. The progeny of the normal (dw+), dwarf (dw), and bantam (dwB) dams were designated as stocks D4.b, D4.c and D4.d, respectively. The dw+ dams were White Leghorn strain cross females. The difference between the rate of laying of normal (69.7%) and their bantam sisters (68.6%) was not statistically significant when the average 32-week body weight of the dw+ sisters was 1,897 g. However, when the 32-week body weight of the normal daughters from the same sires and smaller dams was around 1,646 g, the difference between the rate of laying of the normal (78.1%) and their bantam sisters (75.9%) was significant (P < 0.05). The dwB gene may have a similar but smaller effect on the rate of egg laying than its dwarf allele. The difference between sexual maturity of normal and bantam daughters of either the largest or the smallest dams was not statistically significant, even though the smallest dwB pullets were in average 2.9 days older at first egg. The use of shank length combined with adult body weight allowed a precise discrimination between bantams and dwarfs

THE EFFECT OF PHASE-FEEDING ON EGG PRODUCTION AND EGG QUALITY OF WINTER-HOUSED WHITE LEGHORN HENS

1982 ◽  
Vol 62 (3) ◽  
pp. 887-897 ◽  
Author(s):  
N. A. CAVE ◽  
R. M. G. HAMILTON
Keyword(s):  
Body Weight ◽  
Protein Content ◽  
Egg Production ◽  
Egg Quality ◽  
Performance Criteria ◽  
Feed Consumption ◽  
White Leghorn ◽  
Egg Weight ◽  
Variable Effect

Two experiments with nine strains of Single Comb White Leghorn hens were conducted to compare laying house performance of hens given a diet of uniform protein content or a phase-feeding diet in which protein content was reduced from 156 to 148 and then to 140 g/kg at 273 and 414, or 273 and 384 days of age. Performance criteria were egg production, feed and protein intake, egg, quality, egg weight, mortality and body weight. Phase-feeding allowed reductions of 4.2 and 4.3% in protein consumption without reducing egg production, mortality or, except in one strain, body weight. There was an increase of 0.5% in feed consumption, but feed cost was reduced by 1.3%. Phase-feeding increased Haugh units by 0.3% and decreased specific gravity of eggs in one experiment, decreased percent visibly-cracked eggs in the other experiment and had no effect on percent blood spots. Depending on strain, phase-feeding had a variable effect on egg weight in exp. 1 but had no effect in the second experiment. Key words: Phase-feeding, protein utilization, egg production, hen

Single crossing between White Leghorn and Australorp

1958 ◽  
Vol 9 (6) ◽  
pp. 842 ◽  
Author(s):  
JA Morris ◽  
F Skaller
Keyword(s):  
Body Weight ◽  
Artificial Insemination ◽  
Sexual Maturity ◽  
Egg Production ◽  
The Body ◽  
White Leghorn ◽  
Reciprocal Crosses ◽  
Related Data ◽  
Single Crossing ◽  
White Leghorns

Egg production and related data are presented for 1520 pullets resulting from nine generations of single crossing between White Leghorns and Australorps. Both types of reciprocal crosses were consistently superior to the better of the parental breeds (White Leghorn) in hatchability, chick viability, and egg production. This superiority became still more apparent when pure and crossbred half-sisters were compared. Crossbreeding was not effective in improving the viability of adult birds or the body weight, the latter remaining intermediate between that of the two pure breeds. The number of days required to reach sexual maturity was decreased as a result of crossbreeding. The crossbreds showed less variation in egg production and included in their sample a much smaller percentage of extremely low-producing pullets. A comparison between the two types of crossbreds shoved differences in individual years, but when viewed over the whole period of the experiment the only consistent differences were the superior hatchability and higher fertility, under artificial insemination conditions, when the White Leghorn served as the dam. There were no significant differences in production characters between the two types of crossbreds when housed on deep litter.

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