Sire × hatching season interaction in egg production traits within flocks of domestic fowl

1979 ◽  
Vol 30 (5) ◽  
pp. 991
Author(s):  
BH Yoo ◽  
BL Sheldon
Keyword(s):  
Domestic Fowl ◽  
Variance Component ◽  
Egg Production ◽  
Production Traits ◽  
White Leghorn ◽  
Egg Weight ◽  
Sib Families ◽  
Selection For ◽  
Efficiency Of Selection ◽  
Season Interaction

The extent of sire x hatching season interaction in egg production characters has been studied in White Leghorn, Australorp and Synthetic flocks in which half-sib families bred from the same sires were mated largely to the same dams for spring and autumn hatchings. Interaction appeared to be more important in White Leghorn and Synthetic than in Australorp. The estimate of variance component for interaction was not consistent among the three flocks, and it was important only in certain flocks for different characters: age at first egg, part-annual hen-housed production (PHP), and egg weight at 34 and 62 (EWL) weeks of age in Synthetic; and annual survivors' production and egg specific gravity at 62 weeks of age (SGL) in White Leghorn. Comparison of within-season and across-seasons heritabilities showed that the former could be on average more than 45% higher than the latter in PHP, EWL, SGL and annual hen-housed production. As the estimates of the genetic correlation coefficient between seasons tend to be below 1.0 for many characters in White Leghorn and Synthetic, the sire x hatching season interaction may need to be taken into account and investigated further to improve the efficiency of selection for egg production.

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 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 Heterosis effect in hybrid laying hens

2014 ◽  
Vol 30 (2) ◽  
pp. 303-311 ◽  
Author(s):  
P. Hristakieva ◽  
M. Oblakova ◽  
M. Lalev ◽  
N. Mincheva
Keyword(s):  
Sexual Maturity ◽  
Egg Production ◽  
Live Weight ◽  
Egg Laying ◽  
Production Traits ◽  
Egg Weight ◽  
Group V ◽  
Paternal Line ◽  
Group I ◽  
Heterosis Effect

The new original egg laying lines T, P and N selected at the Institute of Agriculture - Stara Zagora were used. Hybrid ?? ? ??, ?? ? ?? crosses were obtained and used for paternal line. Thereafter, the following breeding schedule of paternal and maternal lines was applied: Group I - (?????)? ?N?; group ?? - (?????)? ?N?; group ??? - ???N?; and group ?V - ???N?. The production traits of original and hybrid birds were recorded: live weight at the age of 8 and 18 weeks, age of sexual maturity in days, 150 days egg production, average egg weight - at 2-week intervals until end of lay; livability, heterosis effect. The live weights of hybrids at 8 and 18 weeks of age were statistically significantly lower compared to original lines. The values of heterosis for this parameter were negative for all four hybrid combinations. The earliest beginning of egg lay occurred in (?????) ? ?N? (162.08 days of age) and ???N? (163.11 days of age). The relative (%) heterosis for age of sexual maturity of studied hybrid combinations had moderate to low negative values. Average egg weights of hybrids were higher and the values of heterosis - positive for all four groups varying from 0.97% to 1.63%. The average 150 days egg production was lower in purebred lines compared to hybrids. The highest average 150 days egg production was determined in ???N? hybrids - 142 eggs. The heterosis effect for egg production in hybrids was significant.

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)

THE EFFECT OF GRADED LEVELS OF NICARBAZIN ON REPRODUCTIVE PERFORMANCE OF LAYING HENS

1989 ◽  
Vol 69 (3) ◽  
pp. 757-764 ◽  
Author(s):  
S. LEESON ◽  
L. J. CASTON ◽  
J. D. SUMMERS
Keyword(s):  
Reproductive Performance ◽  
Feed Intake ◽  
Egg Production ◽  
Visual Loss ◽  
Laying Hens ◽  
Marked Effect ◽  
Significant Loss ◽  
White Leghorn ◽  
Egg Weight ◽  
Egg Shell

Three experiments were undertaken to investigate the coccidiostat, nicarbazin, on reproductive performance of layers. In trial 1, levels of 0, 5, 10, 20, 40, 80, 125, and 200 ppm nicarbazin were fed to White leghorn laying hens for 5 wk. By the 2nd week of nicarbazin treatment, egg production was significantly reduced in birds fed 125 and 200 ppm (P < 0.05). Similarly, increasing levels of nicarbazin resulted in decreasing egg weights (P < 0.01) and feed intake was significantly decreased. However, by the 2nd week post-nicarbazin treatment, egg production, egg weight, and feed intake had returned to normal. Nicarbazin had no effect on egg shell deformation or body weight. Nicarbazin had a marked effect on hatchability; levels of 125 and 200 ppm reduced hatchability significantly (P < 0.01) as well as producing an increased incidence of malpositions and malformations. When nicarbazin was withdrawn from the diet, hatchability returned to pretreatment values although malpositions and malformations were still in evidence. Experiments 2 and 3 were designed to study the effect of nicarbazin on production of brown-shelled eggs. In the 2nd experiment 0, 5, 10, 20, and 40 ppm of dietary nicarbazin resulted in significant loss of shell color at 20 and 40 ppm, whereas in exp. 3 with levels of 0, 80, 125, and 200 ppm, brown eggs lost virtually all their color. It is concluded that the adult White Leghorn bird can tolerate up to 125 ppm nicarbazin without significant (P < 0.01) loss of reproductive performance although lower levels show a trend for reduced production. Hatchability is depressed with nicarbazin levels in excess of 80 ppm, while trace levels will produce a visual loss of color in brown-shelled eggs. Key words: Layer, coccidiostat, reproductive performance

scholarly journals The effect of cage and house design on egg production and egg weight of White Leghorn hens: An epidemiological study

2012 ◽  
Vol 91 (7) ◽  
pp. 1522-1535 ◽  
Author(s):  
J.P. Garner ◽  
A.S. Kiess ◽  
J.A. Mench ◽  
R.C. Newberry ◽  
P.Y. Hester
Keyword(s):  
Epidemiological Study ◽  
Egg Production ◽  
White Leghorn ◽  
Egg Weight ◽  
House Design

Genetic parameters for egg weight v. age curve, and other egg production and egg weight traits, in synthetic lines of chickens

1983 ◽  
Vol 34 (1) ◽  
pp. 85 ◽  
Author(s):  
BH Yoo ◽  
BL Sheldon ◽  
RN Podger
Keyword(s):  
Standard Deviation ◽  
Genetic Correlation ◽  
Egg Production ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Egg Mass ◽  
Control Line ◽  
Egg Weight ◽  
Egg Number ◽  
Selection For

An exponential curve, W = P-Qexp(- Rt), where W is egg weight at age t, was fitted to egg weights of individual pullets, and genetic parameters were estimated for P, Q and R, the residual standard deviation and other egg weight and egg production characters. The data consisted of records collected over six generations on more than 4000 pullets in two selection lines and a control line which originated from a synthetic gene pool of White Leghorn x Australorp crosses. The half-sib and offspring-on-parent regression estimates of heritability pooled over the lines were 0.23 and 0.33 for P, 0.14 and 0.20 for Q, and 0.14 and 0.25 for R. Genetic correlations were estimated to be -0.10 between P and Q, -0.46 between P and R, and 0.90 between Q and R. These estimates suggest that the egg weight v. age curve may be modified to increase the proportion of eggs in desirable weight grades and reduce the incidence of oversized eggs later in the production year. The genetic correlation between mean weight of first 10 eggs and egg weight at 62 weeks of age was estimated to be 0.68, further suggesting that early egg weight may be improved partly independently of late egg weight. The heritability estimates of egg mass output were not higher than those of egg number in spite of the highly heritable average egg weight being an important component of egg mass, probably because of the negative genetic correlation (r = -0.49) between egg number and average egg weight. The standard deviation of individual pullet's egg weights was moderately heritable and genetically correlated positively with egg weight characters and negatively with egg production; these estimates were consistent with the responses to selection for reduced egg weight variability observed elsewhere

Genetic parameters associated with characters effecting egg production in the domestic fowl. I. Heritability of total egg production during the pullet year

1956 ◽  
Vol 7 (6) ◽  
pp. 625 ◽  
Author(s):  
BL Sheldon
Keyword(s):  
Standard Error ◽  
Domestic Fowl ◽  
Egg Production ◽  
Genetic Parameters ◽  
Research Centre ◽  
Narrow Sense ◽  
White Leghorn ◽  
Components Of Variance ◽  
Production Index ◽  
The Mean

Egg production records of White Leghorn pullets hatched a t the Poultry Research Centre, Werribee, Vic., during 1947 to 1950 inclusive have been analysed both on a hen-housed (Production Index) and a survivor basis. Estimates of heritability were obtained by two methods: (1) by the analysis of components of variance between families of full sibs and half-sibs; (2) by estimating the intra-sire regression of the mean performance of offspring on dam's performance. Heritability, in the narrow sense, of Production Index during the pullet year is shown to be 23-30 per cent. with a reasonably low standard error, while heritability of survivors' production is slightly lower but not significantly so. Possible reasons are advanced for the low estimates of heritability of survivors' production.

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

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