Serum concentrations of melatonin in prepubertal gilts exposed to either constant or stepwise biweekly alteration in scotophase

Green, M.L.; Clapper, J. A.; Andres, Carlos; Diekman, M. A.

doi:10.1016/0739-7240(96)00045-8

Cited by 17 publications

(11 citation statements)

References 21 publications

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“…There has been speculation that the absence or attenuation of the melatonin response in domestic pigs, as a result of an alteration in genotype or the different light conditions associated with the domesticity, may explain the reduced influence of season on reproduction in the domestic pigs when compared with the European wild boar [Green et al, 1996]. The aims of the present study were to confirm that there was a circadian pattern in melatonin secretion in the European wild boar under its natural lighting conditions and to compare it with the melatonin patterns of the domestic pigs reared indoors under the lighting conditions typical of commercial indoor piggeries.…”

Section: Introductionmentioning

confidence: 99%

Seasonal alterations in circadian melatonin rhythms of the European wild boar and domestic gilt

Tast

Hälli

Ahlström

et al. 2001

Journal of Pineal Research

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The aims of the present study were: 1) to determine if the European wild boar exhibits a circadian pattern of melatonin secretion under its natural light environment; 2) to compare this pattern with the pattern in domestic pigs reared under the light environment typical for domesticity; and 3) to determine if there are seasonal alterations in melatonin rhythms. Four to six young, pure-bred, European wild boars and four to six cross-bred (Yorkshire x Finnish Landrace) domestic gilts were sampled at 2-hr intervals for 48 hr at the spring/autumn equinoxes and summer/winter solstices. Samples were obtained via saphenous arterial catheters from the wild boars and via ear vein catheters from the domestic gilts. The ambient light intensity was recorded simultaneously with sampling both outdoors and indoors. Following ether extraction, the serum samples were assayed for melatonin using a commercial RIA (Bühlman). All the experimental animals exhibited a distinct circadian pattern in melatonin secretion, with high concentrations occurring during the scotophase. There was no difference in scotophase melatonin response between the wild boars and domestic gilts in any season in terms of mean melatonin concentration or peak value. The mean duration of increased melatonin secretion (more than two standard deviations over a mean photophase concentration) in 24 hr in the wild boars in spring, summer, autumn and winter, was 10, 6, 11 and 17 hr, respectively, and in the domestic gilts, 9, 8, 12 and 11 hr, respectively. These results demonstrate the existence of circadian rhythm in melatonin secretion in both the European wild boar and domestic pig. In both groups, the duration of secretion is subject to seasonal alterations. The results suggest no difference in photoperiodic-melatonin transduction between the European wild boar and domestic pig whether due to altered genotype or reduced light environment.

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Section: Introductionmentioning

confidence: 99%

Seasonal alterations in circadian melatonin rhythms of the European wild boar and domestic gilt

Tast

Hälli

Ahlström

et al. 2001

Journal of Pineal Research

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“…Most of the studies have concluded that the domestic pig does not exhibit a circadian melatonin pattern typical of other mammalian species [Minton et al, 1989;Diekman et al, 1992;Diekman and Green, 1997]. Some studies have concluded that circadian melatonin pattern is evident only under certain lighting regimens or only in some individuals [McConnell and Ellendorff, 1987;Griffith and Minton, 1992;Green et al, 1996;Bollinger et al, 1997]. However, there are two studies that have demonstrated clear and repeatable melatonin profiles in pigs under different lighting conditions [Paterson et al, 1992;Tast et al, 2001].…”

Section: Introductionmentioning

confidence: 99%

The pattern of melatonin secretion is rhythmic in the domestic pig and responds rapidly to changes in daylength

Tast

Love

Evans

et al. 2001

Journal of Pineal Research

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The aim of the study was to investigate the capability of pigs to respond to abrupt changes in lighting conditions by means of alterations in circadian melatonin profiles. Sixteen pre-pubertal crossbred male pigs weighing 40-45 kg were housed in individual pens in four temperature- and lighting-controlled climate rooms (four pigs per room). In two rooms there was a light-dark cycle of 16 L:8 D (Group A) and in two other rooms 8 L:16 D (Group B). Under both lighting regimens light intensity at pig eye-level was 220-240 lx during the light phase and less than 7 lx (red light) during the dark phase. The lighting regimens were changed after 2 wks to the opposite regimen and the change was repeated after a further 2 wks, so that animals ended up with the same light cycle with which they started. Blood was sampled at 2-hr intervals for 48 hr spanning each time of change in lighting. A further 24-hr sampling was performed at the end of the experiment (2 wks after the last change) in both groups and 1 wk after the change from short to long day lighting in Group A. On 83/86 occasions, pigs exhibited a clear circadian rhythm in plasma melatonin under both lighting regimens. Pigs responded immediately to the change from long to short day lighting by advancing melatonin secretion to the earlier lights-off time and some pigs were able to extend secretion to the delayed lights-on time. For short to long day changeover there was a small immediate response, with secretion pattern following the previously entrained endogenous rhythm to within 3 hr of the previous lights-on time. After 1 wk commencement of secretion was delayed by up to 2 hr, while after 2 wks some pigs were able to delay commencement of secretion until lights-off or to cease at lights-on. It is concluded that the domestic pig is able to commence adjustment to abrupt changes in photoperiod within a 1-wk acclimatization by altering circadian melatonin secretion. The present study suggests that it may be possible to use simplified lighting regimens instead of stepwise changing lighting programs in commercial piggeries to reduce the influence of season on production.

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“…However, there is some contradiction as to whether there is a circadian rhythm of melatonin secretion in swine. Some authors did not find a clear diurnal rhythm (McConnell and Ellendorff 1987;Minton et al 1989;Diekman et al 1992;Bollinger et al 1997), whereas recent studies did report such a cycle (Green et al 1996;Andersson et al 2000;Tast et al 2001). The lower circulating concentrations of melatonin in TRT sows on day 4 of lactation could likely be explained by the fact that they were exposed to only 1 h of darkness from day 112 of gestation until day 4 of lactation.…”

Section: Discussionmentioning

confidence: 56%

“…Melatonin is another hormone that could likely be affected by photoperiod since it is secreted during darkness (McConnell and Ellendorff 1987;Green et al 1996). However, there is some contradiction as to whether there is a circadian rhythm of melatonin secretion in swine.…”

Section: Discussionmentioning

confidence: 99%

Impact of an extended photoperiod in farrowing houses on the performance and behaviour of sows and their litters

Lachance¹,

Laforest²,

Devillers³

et al. 2010

Can. J. Anim. Sci.

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Lachance, M. P., Laforest, J. P., Devillers, N., Laperrie`re, A. and Farmer, C. 2010. Impact of an extended photoperiod in farrowing houses on the performance and behaviour of sows and their litters. Can. J. Anim. Sci. 90: 311Á319. The effects of an extended photoperiod around parturition and throughout lactation on performances of primiparous sows and their piglets were studied. Sows were assigned to two light regimens: (1) standard (CTL, n 028), 8 h of daily light from day 112 of gestation until day 23 of lactation; and (2) extended (TRT, n 026), 23 h of daily light from day 112 of gestation to day 4 of lactation and 16 h thereafter. Colostrum intake was estimated based on a 24-h piglet weight gain starting at the end of farrowing. Piglets were weighed on days 4, 7, 14, 21 (weaning on day 23), 35 and 56. On days 4 and 21 of lactation, milk and blood samples were obtained. Behaviour was recorded on days 3 and 20. Piglet feed intakes were noted post-weaning until day 56. The TRT sows had lower concentrations of melatonin than the CTL sows on day 4 (PB0.05), but prolactin concentrations, milk composition and colostrum intake by piglets were unaffected by treatment (P0.1). Litter growth during lactation was unaffected (P0.1), but TRT piglets consumed less feed between 23 and 34 d of age (P B0.05) and weighed less on day 35 (PB0.05). The TRT piglets were more active than CTL piglets on day 3 of lactation only (PB0.05). Increasing the period of daily light in the farrowing house did not improve the performance of primiparous sows and their piglets.

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Serum concentrations of melatonin in prepubertal gilts exposed to either constant or stepwise biweekly alteration in scotophase

Cited by 17 publications

References 21 publications

Seasonal alterations in circadian melatonin rhythms of the European wild boar and domestic gilt

Seasonal alterations in circadian melatonin rhythms of the European wild boar and domestic gilt

The pattern of melatonin secretion is rhythmic in the domestic pig and responds rapidly to changes in daylength

Impact of an extended photoperiod in farrowing houses on the performance and behaviour of sows and their litters

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