A comparison of the effects of age at photostimulation on sexual maturity and egg production in domestic fowl, turkeys, partridges and quail

1998 ◽  
Vol 54 (2) ◽  
pp. 119-128 ◽  
Author(s):  
P.D. Lewis ◽  
T.R. Morris
Keyword(s):  
Domestic Fowl ◽  
Sexual Maturity ◽  
Egg Production

The utilization of glucose by tissue slices of liver and other organs of the domestic fowl

1968 ◽  
Vol 46 (10) ◽  
pp. 1321-1326 ◽  
Author(s):  
H. J. Duncan
Keyword(s):  
Fatty Acids ◽  
Total Lipid ◽  
Rat Heart ◽  
Domestic Fowl ◽  
Sexual Maturity ◽  
Egg Production ◽  
Tissue Slices ◽  
Liver Slices ◽  
Mammalian Tissues ◽  
Oxidation Of Glucose

The utilizations of glucose-1-14C, glucose-6-14C, and glucose-U-14C by liver slices from the immature and the laying domestic fowl have been evaluated. The relative degrees of incorporation of C-1 and C-6 into CO2, total lipid, fatty acids, and glyceride-glycerol resulted in C-1/C-6 quotients that approximated unity for both groups of fowl. The amounts of incorporation of the two specifically labelled carbon atoms into glycogen were significantly different for liver from the immature bird, but not for that from the laying fowl. These results indicate that the commencement of egg production is not accompanied by activation of the phosphogluconate oxidative pathway.When compared on a DNA basis, the amounts of isotope from glucose-U-14C incorporated into CO2, total lipid, fatty acids, glyceride-glycerol, and glycogen by liver slices from the immature fowl were almost equal to the degrees of incorporation observed following incubation of liver obtained from laying birds. The results with glucose-U-14C suggest that little or no modification of carbohydrate metabolism occurred when sexual maturity was reached.Yields of 14CO2 from the oxidation of glucose-1-14C and glucose-6-14C by various fowl tissues other than the liver are also reported. The observed C-1/C-6 ratios were in general lower than values reported in the literature for corresponding mammalian tissues, except that the quotients for fowl heart and ovary were higher than those reported for rat heart and ovary.

The Inheritance of Egg Production in the Domestic Fowl

1943 ◽  
Vol 77 (769) ◽  
pp. 119-132 ◽  
Author(s):  
I. Michael Lerner ◽  
Lewis W. Taylor
Keyword(s):  
Domestic Fowl ◽  
Egg Production

scholarly journals THE CORRELATION BETWEEN BODY PIGMENTATION AND EGG PRODUCTION IN THE DOMESTIC FOWL

Genetics ◽  
1917 ◽  
Vol 2 (2) ◽  
pp. 205-205
Author(s):  
J Arthur Harris ◽  
A F Blakeslee ◽  
D E Warner ◽  
Wm F Kirkpatrick
Keyword(s):  
Domestic Fowl ◽  
Egg Production ◽  
Body Pigmentation

The population dynamics of metacercariae of Apatemon gracilis (Trematoda: Digenea) in three species of lake-dwelling leeches

Parasitology ◽  
1986 ◽  
Vol 93 (3) ◽  
pp. 517-530 ◽  
Author(s):  
S. M. Spelling ◽  
J. O. Young
Keyword(s):  
Population Dynamics ◽  
Relative Density ◽  
Sexual Maturity ◽  
Egg Production ◽  
Seasonal Pattern ◽  
Distinct Pattern ◽  
The Other ◽  
Mean Intensity ◽  
Density Values ◽  
Host Mortality

SUMMARYMonthly samples of the leeches Erpobdella octoculata, Glossiphonia complanata and Helobdella stagnalis were taken over a two-year period from an eutrophic, English lake to detect metacercariae of the trematode, Apatemon gracilis. In each cohort of each of the three leeches, prevalence was low in young individuals, rose to a peak in autumn/winter, and then declined until the cohort had almost died out; in E. octoculata and H. stagnalis a final brief increase occurred. Mean intensity and relative density values followed a similar seasonal pattern of change to that of prevalence in these last two species, but in G. complanata values fluctuated irregularly with no distinct pattern. The frequency distribution of the parasite in G. complanata was highly over-dispersed, but less so in the other two species. Infected E. octoculata reached sexual maturity. The parasite reduced egg production in G. complanata and H. stagnalis, but only by maximum values of 2·5 and 9% respectively. This reduction in fecundity is low compared to the subsequent high mortality, at 95% or more, of newly recruited young from as yet unidentified causes. Parasite-related host mortality was difficult to assess in young leeches, but there was some evidence for its occurrence in older leeches of E. octoculata and H. stagnalis. However, this is unlikely to play a prominent role in the control and regulation of lacustrine leech populations.

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.

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