Photorefractoriness in turkey breeder hens is affected by age and season
نویسندگان
چکیده
منابع مشابه
Photoresponsiveness of turkey breeder hens changes during the egg-laying season: relative and absolute photorefractoriness.
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...
متن کاملAhemeral lighting of turkey breeder hens. 2. Early age at lighting and reproductive performance.
An experiment was conducted to determine whether ahemeral lighting (AH) could be used to obtain increased egg weight and poult weight and otherwise normal reproductive performance in Large White turkey hens lit as early as 26 wk of age. The experimental design utilized a 2 x 2 factorial arrangement of treatments that evaluated two light cycle lengths (24 h, control and 28 h, ahemeral) at two he...
متن کاملInitiating egg production in turkey breeder hens: thyroid hormone involvement.
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...
متن کاملFeed restriction of turkey breeder hens--a review.
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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ژورنال
عنوان ژورنال: Poultry Science
سال: 2002
ISSN: 0032-5791
DOI: 10.1093/ps/81.5.689