The role of retinal and extra-retinal photostimulation in reproductive activity in broiler breeder hens.
Photostimulation of retinal photoreceptors, which are sensitive to green light, appears to inhibit reproductive activity in birds, whereas photostimulation of extra-retinal photoreceptors, which are sensitive to red light, accelerates it. The objective of this study was to determine the effect of either retinal or extra-retinal photostimulation on reproductive activities of broiler breeder hens. At 23 wk of age, Cobb hens (N=135) were divided into 9 rooms with individual cages (n=15). At 24 wk of age, 3 rooms were photostimulated (14L:10D) with white light (Control, n=45). Six rooms had 2 parallel lighting systems, red (660 nm) and green (560 nm), which were both on during 6 out of 14 h of the light period. Then, in 3 of these rooms, the green light was turned off and hens were exposed to a total of 14 h of red light (Red, n=45), and in the other 3, the red light was turned off and green lighting continued for a total of 14 h (Green, n=45). The Green group had reduced egg production; reduced plasma concentrations of ovarian steroids; reduced luteinizing hormone (LH)-beta, vasoactive intestinal peptide (VIP), and prolactin mRNA expression; and greater retinal green opsin mRNA expression (P < or = 0.05). The Red group had greater egg production; greater gonadotropin-releasing hormone-I (GnRH-I) and red opsin gene expression in the hypothalamus; and lesser green opsin gene expression in the retina (P < or = 0.05). We suggest that selective photostimulation of extra-retinal photostimulation as opposed to retinal photostimulation is a key factor in the determination of successful reproduction of broiler breeder hens.
Mobarkey
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Department of Animal Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel. mobarkey@agri.huji.ac.il
Avital
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N
Heiblum
R
R
Rozenboim
I
I
D000818:Animals; D002645:Chickens / Q000502:physiology*; D004958:Estradiol / Q000097:blood; D005260:Female; D037201:Follicle Stimulating Hormone, beta Subunit / Q000235:genetics; D015870:Gene Expression / Q000528:radiation effects; D007987:Gonadotropin-Releasing Hormone / Q000235:genetics; D008027:Light; D037101:Luteinizing Hormone, beta Subunit / Q000235:genetics; D010775:Photic Stimulation; D017440:Photoperiod; D010786:Photoreceptor Cells / Q000502:physiology / Q000528:radiation effects; D020419:Photoreceptor Cells, Vertebrate / Q000502:physiology / Q000528:radiation effects; D016133:Polymerase Chain Reaction; D011374:Progesterone / Q000097:blood; D011388:Prolactin / Q000235:genetics; D012098:Reproduction / Q000528:radiation effects*; D012160:Retina / Q000528:radiation effects*; D017299:Rod Opsins / Q000235:genetics; D013739:Testosterone / Q000097:blood; D014660:Vasoactive Intestinal Peptide / Q000235:genetics
D037201:Follicle Stimulating Hormone, beta Subunit; D037101:Luteinizing Hormone, beta Subunit; D017299:Rod Opsins; C095855:long-wavelength opsin; D007987:Gonadotropin-Releasing Hormone; D014660:Vasoactive Intestinal Peptide; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol; D011388:Prolactin