Estimating Age at Sexual Maturity from Flock Records
نویسندگان
چکیده
منابع مشابه
Inheritance of Age at Sexual Maturity
Dr. RAYMOND PEARL (1912) was the first worker to suggest that sexlinked factors were involved in the inheritance of fecundity. PEARL used as a measure of fecundity the eggs produced during the winter period. He proposed that two major dominant factors were responsible for high egg production, one of which resided in the sex chromosome. GOODALE (1919) and HURST (1921) each failed to confirm the ...
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INTEREST in the genetic effects of irradiation on quantitative characters usually takes the form of two questions. Does irradiation effect a genetic change in the mean of quantitative characters such as human intelligence? Does irradiation induce genetic variance in quantitative characters that could be utilized by the plant or animal breeder for genetic improvement? Experimental data relevant ...
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Despite the widespread assumption that paternal investment is substantial in our species, previous studies have shown mixed results in relation to the impact of fathers on both offspring survival and reproductive outcomes. Using data from a large representative sample of British men, we tested whether father absence is associated with the timing of reproduction-related events among boys, while ...
متن کاملPopulation cycles in small mammals: the role of age at sexual maturity
Several hypotheses have been proposed to explain cyclic fluctuations in abundance of some small mammal populations. These hypotheses have been controversial, however, and there is no consensus among biologists as to why population cycles occur. In a demographically based model, we tested the potential influence of phase-specific changes in life history traits (age at maturity, fertility, juveni...
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BACKGROUND Few human studies have evaluated the impact of childhood exposure to organochlorine pesticides (OCP) on pubertal development. OBJECTIVE We evaluated associations of serum OCP concentrations [hexachlorobenzene (HCB), β-hexachlorocyclohexane (βHCH), and p,p-dichlorodiphenyldichloroethylene (p,p´-DDE)] with age at attainment of sexual maturity among boys. METHODS From 2003 through 2...
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ژورنال
عنوان ژورنال: Poultry Science
سال: 1963
ISSN: 0032-5791
DOI: 10.3382/ps.0420083