Utilization of heterosis in poultry

1958 ◽  
Vol 9 (4) ◽  
pp. 599 ◽  
Author(s):  
FHW Morley
Keyword(s):  
Body Weight ◽  
Genetic Variation ◽  
Genetic Variability ◽  
Sex Chromosome ◽  
Inbred Lines ◽  
White Leghorn ◽  
Egg Weight ◽  
Additive Genetic Variation ◽  
White Leghorns ◽  
Recessive Genes

Records were analysed of 500-day production, egg weight, 11-week and mature body weight, sex maturity, and broodiness of the crossbred progeny of inbred lines of Australorps mated to White Leghorns, and inbred lines of White Leghorns mated to Australorps. Clear differences between lines of both breeds mere found in most characters, indicating the presence of potentially useful amounts of additive genetic variation. Non-additive genetic variation was also found to be present in varying degrees in different characters. Because of the difficulties of developing and maintaining inbred stocks of poultry, and the importance of sex-linked characteristics in some commercial environments, a scheme is proposed which may enable heterosis to be exploited without the use of inbred material. The basis of this scheme is the combination of the White Leghorn sex chromosome, with varying proportions of Australorp and White Leghorn autosomes, in a new breed. Assuming that the heterosis observed in the F1 is due to elimination of certain biochemical blocks determined by recessive genes, the formation of the new breed should enable the methods of closed flock breeding to be used in material at a higher level of production, and likely to contain more genetic variability, than either parent breed.

scholarly journals Phenotypic and Genetic Parameter Estimates for Local Guinea Fowl Production and Some Other Traits

2020 ◽  
pp. 1-12
Author(s):  
Addison Doudu ◽  
Serekye Yaw Annor ◽  
James Kwame Kagya-Agyemang ◽  
Godson Aryee Zagbede ◽  
Clement Gyeabour Kyere
Keyword(s):  
Body Weight ◽  
Genetic Variation ◽  
Weight Gain ◽  
Feed Intake ◽  
Guinea Fowl ◽  
Parameter Estimates ◽  
Egg Weight ◽  
Additive Genetic Variation ◽  
High Heritability ◽  
Heritability Estimates

This study on indigenous Guinea fowls in Ghana was undertaken to estimate genetic variation and heritability of traits in these birds. The study was conducted at the Poultry Section of the Animal farm of the Department of Animal Science Education, University of Education, Winneba, Mampong-Ashanti campus, Ghana, from 2015 to 2018. The data used in the present experiment were collected from six hundred keets (300 males and 300 females) produced from randomly selecting and mating 110 dams and 22 sires and consisted of 780 records collected over a period of 3 years. The genetic parameters were estimated using sire-son, sire-daughter and dam-daughter regression analysis.  Body weight and 8-month weight gain showed the greatest additive genetic variation, with survival, docility, dressing percentage, age at first egg, egg weight, egg number, fertility, hatchability traits, feed intake and FCR showing relatively low additive genetic variation.  Moderate to high heritability estimates were obtained for body weight, weight gain at ages 1day to 2 months, 2-4 months in females, 4-6 months in males, docility, feed intake in females and feed conversion ratio in both males and females. Similarly, moderate to high heritability estimates were also obtained for age at first egg, egg weight and egg numbers. However, all other parameters considered in this study had low heritability estimates. This study concludes that, the results could be used to initiate Guinea fowl selection breeding programmes.

scholarly journals SOCIAL AND PHYSICAL ENVIRONMENTAL INFLUENCES ON CAGED SINGLE COMB WHITE LEGHORN LAYERS

1976 ◽  
Vol 56 (4) ◽  
pp. 733-738 ◽  
Author(s):  
A. E. SEFTON ◽  
D. C. CROBER
Keyword(s):  
Body Weight ◽  
Behavioral Response ◽  
Egg Production ◽  
Environmental Influences ◽  
Inbred Lines ◽  
White Leghorn ◽  
Individual Bird ◽  
Cage Size ◽  
White Leghorns ◽  
Single Comb

Pullets from two-way crosses between three highly inbred lines of Single Comb White Leghorns were housed in two sizes of commercial laying cages, two pullets per cage. Individual bird egg production records were kept when birds were 68–72 wk of age. During this period, peck order within each cage, fearfulness and body weight of each individual were determined. Differences between matings for fearfulness, body weight and egg production were not significant. However, in the case of egg production, both the mating × cage size and mating × cage tier interactions were significant. The genotype × environment interactions were interpreted to be due, in part, to varied behavioral response to the environment. Dominant birds had both a higher rate of egg production and heavier body weight than their subordinate cage mates. Birds housed in the larger cages (516 cm2 per bird) were less fearful than those in the smaller cages (412 cm2 per bird). Lower fearfulness was associated with higher egg production.

Heterosis, recombination effects and genetic variability of egg composition in inbred lines of white leghorns and their crosses

1984 ◽  
Vol 25 (3) ◽  
pp. 361-367 ◽  
Author(s):  
H. Abplanalp ◽  
S. J. Peterson ◽  
S. Okamoto ◽  
Dona Napolitano
Keyword(s):  
Genetic Variability ◽  
Inbred Lines ◽  
White Leghorns ◽  
Egg Composition

Genetic variation in a line of mice selected to its limit for high body weight

1974 ◽  
Vol 19 (3) ◽  
pp. 273-289 ◽  
Author(s):  
W. K. Al-Murrani ◽  
R. C. Roberts
Keyword(s):  
Body Weight ◽  
Genetic Variance ◽  
Genetic Model ◽  
Random Mating ◽  
Inbred Lines ◽  
High Body Weight ◽  
High Body ◽  
Lower Body Weight ◽  
Recessive Genes ◽  
Selection For

SUMMARYA line of mice, at its limit to selection for high body weight did not decline in performance over 11 generations of random mating, neither did it respond when selection was renewed. The experiment tested a method of improving body weight by a scheme which had earlier increased litter size under similar circumstances. The scheme was to derive partially inbred lines from the plateaued line, to select during inbreeding and, finally, to cross the best inbreds. Body weight was not increased, but the study allowed further examination of the residual genetic variance in the line.During inbreeding, the inbred lines became clearly differentiated in body weight, proving that loci controlling body weight had not become fixed. There was also a significant response to selection for a lower body weight during inbreeding. The pattern of results suggested the segregation of recessive genes, detrimental to high body weight but which selection had become inefficient at removing. A genetic model compatible with the results accommodated several such recessives, perhaps as many as 10, each with an effect of about two-thirds of a standard deviation (or some equivalent combination of gene number and effect), and at frequencies of around 0·2. Nevertheless, the total improvement in body weight to be gained by their elimination was only half a gram, or less than 2 %. Thus, substantial genetic effects can occur at individual loci despite trivially low heritabilities and negligible potential gains.

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

scholarly journals A failure to induce heritable changes in four generations of the White Leghorn chicken by inter- and intra-specific blood transfusion

1963 ◽  
Vol 4 (2) ◽  
pp. 221-239 ◽  
Author(s):  
I. L. Kosin ◽  
Masaru Kato
Keyword(s):  
Body Weight ◽  
New Hampshire ◽  
Blood Donors ◽  
Blood Transfusions ◽  
Plumage Colour ◽  
White Leghorn ◽  
Egg Weight ◽  
Injection Period ◽  
White Leghorn Chicken ◽  
Egg Shell

1. A three-year study was conducted to test the efficacy of inter- and intra-specific blood transfusions in domestic poultry for inducing heritable changes in the recipients. The latter were pure-bred White Leghorns. Pure-bred Broad Breasted Bronze turkeys and New Hampshire chickens served as blood donors to two distinct lines of recipients. All injections started when the recipient chicks were 2–5 days old. Altogether, more than 3000 chicks from blood injected lines were involved in the study, conducted between 1959 and 1961 and distributed between the parental and three subsequent generations. Each injected chick received a total of some 155 ml. of whole blood in the course of a five-month injection period. An adequate number of control (non-injected) birds was used throughout. Observations were made on plumage colour, body-weight, egg-weight, egg-shell colour, fertility and hatchability. Furthermore, blood plasma and muscle tissue of appropriate birds were subjected to immunological, chromatographic and electrophoretic analyses.2. On the basis of all these criteria, no evidence of heritable shifts in the direction of the donor organism was discerned among birds belonging to either of the two treated lines.

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 Habilidad combinatoria de 8 líneas élites dominicanas de maíz (Zea Mays L.)

2016 ◽  
Vol 4 ◽  
pp. 65
Author(s):  
José Richard Ortiz ◽  
Pedro Comalat Rodes
Keyword(s):  
Zea Mays ◽  
Genetic Variation ◽  
Grain Yield ◽  
Combining Ability ◽  
Zea Mays L ◽  
Inbred Lines ◽  
Additive Genetic Variation

Twenty eight inter-crosses from a diallel set of 8 Dominican inbred lines of maize were evaluated in 1990. The specific objectives were to determine general(gca) and specific (SCA) combining ability and to predict the best two and three-way hybrids. The inheritance of yield was determined by diaIlel analysis. General and specific (sca) combining ability and specific mean squares were statistically significant in yield, being the additive genetic variation much larger than the non additive variation. The parental T66 and NO3 showed the highest gca values and DK12xT66 (9.02 t/ha),NO2xNO3 (8.57t/ha) and DK12xT66 (8.36 t/ha) the best  sca values. The results partially agree with previous studies. The best three and two way hybrids predictions were (NO3xT66)x NO3 and(NO2xT66) (NO3xDK14) with grain yield of 8.80 and 8.30 t/ha.

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

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