Reddy Ippala Janardhan, David Corbon Godfrey, Selvaraju Sellen, Mondal Sunato, Ravi Kiran Gorti
Animal Physiology Division, National Institute of Animal Nutrition and Physiology, Adugodi, Hosur Road, Bangalore 560 030, India.
Trop Anim Health Prod. 2012 Aug;44(6):1311-7. doi: 10.1007/s11250-012-0073-9. Epub 2012 Apr 25.
The objective of this was to establish the effects of red spectrum of light (650 nm, treated n = 12) and normal spectrum of light (450 nm control = 12) on GnRH-I mRNA expression, amplitude and frequency of luteinizing hormone (LH), and egg production from 72-82 weeks of age in white leghorn hens. Birds exposed to red spectrum of wavelength significantly improved (P < 0.01) steroid hormone, and egg production improved over old laying 72 to 82 weeks. Weekly interval profiles followed the same pattern. At 77th weeks of age blood, samples from both the groups were collected at every 3 h for 36 h to study the pulsatile secretion of LH surges. Plasma LH concentration was higher (P < 0.01) in treated birds with more number of frequencies and amplitude LH surges in plasma of treated birds. LH frequencies were more pronounced and advanced during 36 h of sampling at 3 h interval in treated birds. Weekly interval of plasma LH, E2β, and P(4) concentrations increased (P < 0.01) in treated birds from 72 to 82 weeks of age. GnRH-I mRNA concentration was significantly (P < 0.01) higher in birds exposed to red spectrum of light compared to controls. It is hypothesized that exposure of birds to red spectrum of light-enhanced (P < 0.01) GnRH-I mRNA with more number of yellow yolky follicles was found in birds exposed to red spectrum of light during 77 days (72-82 weeks of age) of experimental period. It is concluded that higher levels of GnRH-I mRNA, LH, E2β, and P(4) concentration with lower incidence of pause days enabled the birds to lay more eggs even later in the productive period by modulating the wavelengths of light under normal husbandry conditions.
本研究的目的是确定红色光谱（650纳米，处理组n = 12）和正常光谱（450纳米，对照组n = 12）对白来航蛋鸡72至82周龄时促性腺激素释放激素-I（GnRH-I）mRNA表达、促黄体生成素（LH）的幅度和频率以及产蛋量的影响。暴露于红色光谱的鸡，其类固醇激素水平显著提高（P < 0.01），且在72至82周龄的老龄产蛋期产蛋量有所增加。每周的间隔情况遵循相同模式。在77周龄时，对两组鸡每3小时采集一次血样，持续36小时，以研究LH脉冲式分泌激增情况。处理组鸡的血浆LH浓度更高（P < 0.01），且处理组鸡血浆中LH激增的频率和幅度更多。在处理组鸡中，以3小时为间隔进行36小时采样期间，LH频率更为明显且提前出现。在72至82周龄的处理组鸡中，血浆LH、雌二醇β（E2β）和孕酮（P4）浓度的每周间隔值均有所增加（P < 0.01）。与对照组相比，暴露于红色光谱的鸡GnRH-I mRNA浓度显著更高（P < 0.01）。据推测，在77天（72至82周龄）的实验期内，暴露于红色光谱的鸡中GnRH-I mRNA增加（P < 0.01），且发现有更多数量的黄色卵黄卵泡。研究得出结论，在正常饲养条件下，通过调节光照波长，较高水平的GnRH-I mRNA、LH、E2β和P4浓度以及较低的停产天数发生率，使鸡即使在生产后期也能产更多蛋。
