The Folic Acid Requirements of Turkey Breeder Hens
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چکیده
منابع مشابه
Iron requirements of broiler breeder hens.
A study was conducted to investigate Fe requirements of broiler breeders. One-hundred-fifty-six Cobb 500 broiler breeder hens were individually placed in electrostatically painted cages at 22 weeks. The study was composed of an adaptation phase, in which hens were fed corn-soy-wheat bran diets until 35 wks. An Fe deficient mash diet (24.6 ppm Fe) was provided from 35 to 46 wk in order to induce...
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Past research on feed restriction methods with turkey breeder hens has involved the feeding of 1) high-fiber or low-energy diets, 2) low dietary protein, 3) limited quantities of feed, 4) rations on a skip-a-day program, 5) distasteful compounds, or 6) combinations of these methods. In general, feed-restricted turkey breeder hens showed a reduction in BW and a delay in sexual maturity at time o...
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The role of thyroid hormones in the expression of photosensitivity-photorefractoriness in female turkeys was investigated through the use of an antithyroidal agent, 6-n-propyl-2-thiouracil (PTU). In experiment 1, females held continuously from hatch on long day lengths (16L:8D; LD) and fed 0.1% PTU from 0 to 16 wk, began laying eggs at 26 wk of age, peaking at 75% hen-day egg production by 29 w...
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Photosensitive species undergo neuroendocrine changes during a reproductive season that cause them to gradually become unresponsive to a photoperiod that initially stimulated reproduction. They may first become relatively photorefractory (rPR), when they will cease egg laying only if photoperiod is reduced, and then absolutely photorefractory (aPR), when they will cease laying despite long day ...
متن کاملExposure duration to long day lengths associated with the expression of photorefractoriness in turkey breeder hens.
In addition to inducing egg production, exposure to long days concomitantly activates processes that eventually result in photorefractoriness (PR) and cessation of egg production. Experiments were conducted to evaluate the duration of exposure to long days that result in these processes. In each of 3 experiments, we subjected Large White turkey breeder hens to long days (16 or 18 h per day) for...
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ژورنال
عنوان ژورنال: Poultry Science
سال: 1956
ISSN: 0032-5791
DOI: 10.3382/ps.0350711