Oviposition patterns and plasma melatonin rhythms in response to manipulations of the light: Dark cycle

Abstract

1. In 2 experiments with Single Comb White Leghorn hens, the effects of different light:dark cycles (LD-cycles) upon oviposition patterns and plasma melatonin rhythms were studied. In experiment 1, a 28-h ahemeral LD-cycle (12L:16D) was used. In experiment 2, a normal 24-h LD-cycle (16L:8D) was applied and the effects of a sudden 8-h forward or backward shift of the 8-h dark period (that is phase-advanced or phase-delayed LD-cycle) were studied. 2. The oviposition patterns as well as the plasma melatonin rhythms were fully synchronised with both LD-cycles (24-h or 28-h). The 2 rhythms were gradually re-synchronised after phase shifts, and the melatonin response phase-led the oviposition response by 2 cycles. Thus, the change of the melatonin rhythm coincided with the change of the (presumed) open period for LH-release. 3. In the unchanged 24-h LD-cycle, ovipositions occurred almost exclusively (98.9%) during light hours, whereas in the 28-h LD-cycle, ovipositions occurred primarily (84.5%) during the last 9 h of the dark period. 4. In both LD-cycles and after changes of the LD-cycle, light always suppressed plasma melatonin, regardless of previous light history. During dark periods, concentrations were elevated but, interestingly, only if darkness had also been experienced during the same time period 24 h earlier. This indicates that light has a direct inhibiting effect upon pineal melatonin release, while actual melatonin release during darkness is controlled by an endogenous clock.

Study of Oviposition Pattern and Clutch Traits in a White Leghorn (WL) Layer Population

“…The mean oviposition time was found to be about 05 h after the onset of light period and about 13 h from onset of darkness. The results are in agreement with the reports of Yoo et al (1986) and Noddegaard (1998). However, it varied from the findings of Lillpers (1991) which might be due to the difference in duration of light-dark cycles and difference in onset of darkness.…”

Egg laying characteristics, egg weight, embryo development, hatching weight and post-hatch growth in relation to oviposition time of broiler breeders

“…The lighting and feeding programs were late for 1 and 1.5 h, respectively, than those of previous studies (Zakaria et al, 2005;Zakaria and Omar, 2013). Both lighting (Noddegaard, 1998) and feeding programs (Backhouse and Gous, 2005) were reported to affect the oviposition times by influencing the timing of LH-release open period. Dopamine was suggested to contribute to the effect of environmental factors such as lighting and feeding programs by regulating the LH-RH synthesis and release in the hypothalamus and median eminence, respectively (Dunn et al, 2009).…”

Genetics and genomics of egg production traits in poultry species

“…Lillpers and Wilhelmson (1993) and Luc et al (1996) published detailed analyses of both the biology and the cycle of egg formation. These developments stimulated research on the possibility of crossing the biological limit of one egg per 24-26 h. One of the newer traits that were a focus of research was oviposition time (Noddegaard, 1998;Lewis et al, 1995Lewis et al, , 2004Roy et al, 2014). Experiments were performed with extending or shortening hours with light (Biellier, 1985;Koelkebeck and Biellier, 1986).…”