Quantitative studies of pancreas and islands of Langerhans in relation to age, sex, and body weight in White Leghorn chickens

1949 ◽  
Vol 84 (2) ◽  
pp. 279-310 ◽  
Author(s):  
Eugene F. Oakberg
Keyword(s):  
Body Weight ◽  
White Leghorn ◽  
Quantitative Studies ◽  
Islands Of Langerhans

Breeding

1931 ◽  
Vol 4 (2) ◽  
pp. 17-28
Keyword(s):  
Body Weight ◽  
The Netherlands ◽  
Point Of View ◽  
The Other ◽  
White Leghorn ◽  
Early Puberty

Investigation into the differences between Barneveld and White Leghorn breeds from a genetical and breeding technic point of view. Report to the Committee of the Netherlands Genetic Society regarding breeding tests with poultry in 1926–1927 and 1928–1929. A. L. Hagedoorn. Züchtungskunde, 1930, p.450.The investigation was carried out in four directions: 1) It was to be ascertained whether a correlation exists between various continuing characteristics appearing in combination in two breeds of poultry (Aziatic and Meditteranean breeds) (coloured eggs, white eggs, white ears, light body weight and early puberty in the other). 2) It was to be investigated whether it was possible to incorporate the qualities of „Brown Egg” and „Early Puberty” in a good laying utility breed. 3) The question was to be treated what gens have influence on the colour of the egg, the colour of the plumage, the colour of the feet etc. 4) Finally data, relating to the value of cross-breeds and their progeny as utility poultry were to be gathered.

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 Photoperiod on growth and egg characteristics of the white leghorn chicken

2021 ◽  
Vol 15 (1) ◽  
pp. 151-155
Author(s):  
Abdul Muumin Sadick ◽  
Iddrisu Mubarik ◽  
Dennis Kodzo Awalime ◽  
Rebecca Akumbilim ◽  
Philip Larweh ◽  
...  
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Feed Intake ◽  
Growth Traits ◽  
Growth Parameters ◽  
Skills Training ◽  
Daily Weight Gain ◽  
White Leghorn ◽  
Initial Body Weight ◽  
Final Body Weight

One hundred and twenty (120) 16 weeks old White Leghorn layer breeds were used for the study. The objective of the study was to determine effect of photoperiod on layer chicken. The research was carried out at the Poultry Section of the Animal farm of the Department of Animal Science Education, Akenten Appiah-Menka University of Skills Training and Entrepreneurial Development, Mampong. Four treatments made up of 12 hours of light, 14 hours of light, 16 hours of light and 18 hours of light were used for the study. Each treatment was replicated three times with 10 birds per replicate in a Completely Randomized Design. Birds were exposed equally to common daylight and in the evenings, lights were turned on at specified periods. Growth parameters measured were initial body weight, daily feed intake, daily weight gain and final body weight. Egg traits measured were egg weight, albumen height, yolk color and yolk weight. The data collected were analyzed using General Linear Model procedure of Statistical Analysis System. Results from the study indicated that, varied photoperiod regimes had no significant (P>0.05) effect on initial body weight, daily feed intake but had significant (P<0.05) effect on daily weight gain and final body weight of growth traits. Photoperiod had no significant (P>0.05) effect on the egg characteristics of the white Leghorn layer bird. It was concluded from the study that, increasing photoperiod had no positive effect on growth and egg characteristics of the white Leghorn layer.

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.

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.

Carcass traits and reproductive organ morphology in 62-week-old SCWL hens

1995 ◽  
Vol 75 (3) ◽  
pp. 341-344 ◽  
Author(s):  
H. L. Bjerstedt ◽  
F. E. Robinson ◽  
R. T. Hardin ◽  
T. A. Wautier
Keyword(s):  
Body Weight ◽  
Follicular Development ◽  
Reproductive Organ ◽  
Breast Muscle ◽  
Liver Fat ◽  
White Leghorn ◽  
Reproductive Disorders ◽  
Fat Pad ◽  
Muscle Weight ◽  
Single Comb

The influence of body weight on reproductive organ morphology and the incidence of reproductive disorders was investigated with 324 Shaver Starcross 288-strain Single Comb White Leghorn hens at 62 wk of age. The hens were fed a typical laying ration (2720 kcal ME kg−1, 16.3%, CP, 3.5% Ca) ad libitum. All birds were housed two birds per cage in a windowless poultry house, with a photoperiod of 14L:10D. The total group of hens was separated into eight weight groups, on the basis of 62-wk body weight, ranging from 1100 to 2700 g, at 200-g increments. Birds were killed by cervical dislocation and dissected to observe carcass and reproductive organ traits. The length of the shank and the weights of the breast muscle, liver, fat pad, ovary and ovarian stroma increased significantly as hen weight increased. Ovary weight was increased because of an increase in the number of large follicles, as well as an increase in the weights of individual large follicles Ovarian regression occurred more often in hens weighing less than 1700 g than in hens weighing more than 1700 g. Internal oviposition occurred most often in hens near the population body weight (1803 g). Internal ovulation occurred more often in hens more than 1900 g in body weight than in hens less than 1900 g. These data suggest that hens that are heavier than average have increased follicular development, compared with low-weight hens. Key words: Single Comb White Leghorn, abdominal fat pad weight, breast-muscle weight, body weight, ovary morphology, reproductive disorders

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
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