Age and Body Weight at Sexual Maturity in Female White Leghorn Chickens
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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The degree of asymmetry in bilateral morphological characters may reflect genetic and environmental stressors. Shank length and diameter, weight and length of the first primary wing feather, and distance between the junction of upper and lower mandibles and auditory canal (face length) were used to classify bilateral types and measure relative asymmetry (RA) in six genetic stocks. The stocks we...
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Onset of sexual maturation is a trait of extreme importance both evolutionarily and economically. Unsurprisingly therefore, domestication has acted to reduce the time to sexual maturation in a variety of animals, including the chicken. In comparison with wild progenitor chickens [the Red Junglefowl (RJF)], domestic layer hens attain maturity approximately 20% earlier. In addition, domestic laye...
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چکیده هدف اصلی تحقیق حاضر مطالعه و بررسی رابطه بین خودکارامدی شنیداری با درک شنیداری بود.همچنین رابطه درک شنیداری وخودکارآمدی شنیداری با جنسیت و رابطه خودکارامدی شنیداری با سن نیز مورد بررسی قرار گرفت.تعداد شصت زبان اموز-سی دختر و سی پسر- کانون زبان ایران در مرکز خرم آباد به صورت تصادفی انتخاب شدند. روشهای به کار رفته در جمع اوری داده ها عبارت بودند ازبرسشنامه خودکارآمدی و تست درک شنیداری لانگ...
15 صفحه اولBody Weight and Food Intake of Broiler and Leghorn Chicks
Age of market weight of broilers has been continuously reduced by approximately one day per generation during the past 40 50 years due to an average increase of 50 g/year of body weight at 42 days of age (Gyles, 1989). Although non-genetic factors such as improved feeding and management contributed to this growth rate increase, genotypic selection for growth seems to be the major cause (Chamber...
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ژورنال
عنوان ژورنال: Poultry Science
سال: 1984
ISSN: 0032-5791
DOI: 10.3382/ps.0630828