A note on simulating the `observer effect' using constant photoperiod on nursery pigs

Lay, D. C.; Buchanan, H. S.; Haussmann, Mark F.

doi:10.1016/s0168-1591(99)00018-0

Cited by 11 publications

(7 citation statements)

References 10 publications

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“…However, access to artificial light could alter their behavior. As reported by Lay et al (1999), pigs with constant access to light were more active between 1830 and 0630 h than pigs subjected to a 12 h light-12 h dark cycle. To our best knowledge, there are no studies that reported pigs' activity in a pen with daylight access and artificial light illuminating the weighing scale in the pen.…”

supporting

confidence: 62%

Analyses of body weight patterns in growing pigs: a new view on body weight in pigs for frequent monitoring

Stygar

Dolecheck

Kristensen

2018

Animal

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Frequent BW monitoring of growing pigs can be useful for identifying production (e.g. feeding), health and welfare problems. However, in order to construct a tool which will properly recognize abnormalities in pigs' growth a precise description of the growth process should be used. In this study we proposed a new model of pig growth accounting for daily fluctuations in BW. Body weight measurements of 1710 pigs (865 gilts and 843 barrows) originating from five consecutive batches from a Danish commercial farm were collected. Pigs were inserted into a large pen (maximum capacity = 400) between November 2014 and September 2015. On average, each pig was observed for 42 days and weighed 3.6 times a day when passing from the resting to feeding area. Altogether, 243,160 BW measurements were recorded. A multilevel model of pig growth was constructed and fitted to available data. The BW of pigs was modeled as a quadratic function of time. A diurnal pattern was incorporated into the model by a cosine wave with known length (24 h). The model included pig effect which was defined as a random autoregressive process with exponential correlation. Variance of within-pigs error was assumed to increase with time. Because only five batches were observed, it was not possible to obtain the random effect for batch. However, in order to account for the batch effect the model included interactions between batch and fixed parameters: intercept, time, square value of time and cosine wave. The gender effect was not significant and was removed from the final model. For all batches, morning and afternoon peaks in the frequency of visits to the feeding area could be distinguished. According to results, pigs were lighter in the morning and heavier in the evening (minimum BW was reached around 1000 h and maximum around 2200 h). However, the exact time of obtaining maximum and minimum BW during the day differed between batches. Pigs had access to natural light and, therefore, existing differences could be explained by varying daylight level during observations periods. Because the diurnal amplitude for pig growth varied between batches from 0.9 to 1.4 kg, BW monitoring tools based on frequent measurements should account for diurnal variation in BW of pigs. This proposed description of growth will be built into a monitoring tool (a dynamic linear model) and applied to farm data in future studies.

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confidence: 62%

Analyses of body weight patterns in growing pigs: a new view on body weight in pigs for frequent monitoring

Stygar

Dolecheck

Kristensen

2018

Animal

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“…Although nighttime illumination Zoo Biology DOI 10.1002/zoo seems to alter the nocturnal behavior of some animals, such as pigs and bulls [Nicks et al, 1988;Lay et al, 1999], the effect of nighttime illumination on captive cetaceans is largely unknown. Under two 500-W aerial lamps (illuminance unavailable), Lyamin et al [2000] found that resting in a captive gray whale (Eschrichtius robustus) was observed mainly at night.…”

Section: Discussionmentioning

confidence: 99%

Diurnal changes of behavior and respiration of Yangtze finless porpoises (Neophocaena phocaenoides asiaeorientalis) in captivity

Xiao

Wang

2005

Zoo Biol.

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A preliminary study was carried out to investigate diurnal changes of behavior of three, one adult male, one adult female, and one juvenile female, Yangtze finless porpoises (Neophocaena phocaenoides asiaeorientalis) in captivity. The respiration and behavior of the porpoises were recorded for 222 hr across 42 days. Behavioral data were recorded for eight general categories: aerial display and fast swimming, begging for fish, playing, nonsexual socializing, sexual behavior, resting, rubbing, and miscellaneous (i.e., other behaviors not included in the above categories). Each behavioral category was scored using one-zero sampling with 10-min intervals. The adult male showed shorter mean respiratory intervals at night (19:00-7:00 h), whereas the mean respiratory intervals of the females were shorter during the day (7:00-19:00 h). Begging for fish of all individuals, playing of the juvenile female, nonsexual socializing, and miscellaneous behavior of the adult female and resting of the male were observed more easily in the day, and aerial display and fast swimming of the adults and resting of the females were observed more easily at night. No significant diurnal difference was found, however, in the remaining categories of each individual. Each of the three porpoises therefore showed a distinct diurnal pattern, but none was obviously more active in the daytime than during the nighttime. Results suggest that daytime-only feeding schedules may be insufficient to meet the energetic needs of marine mammals that show a 24-hr activity cycle, and that nighttime feeding may be a worthwhile addition to husbandry routines.

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“…Lay et al (1999) also showed that weaned piglets subjected to 24 h of daily light were more active between 1830 and 0630 than piglets subjected to 12 h of daily light, and tended to be more active during the entire day. One could postulate that the increased activity level of TRT piglets, leading to greater energy expenditure, may have masked any beneficial effect that the long photoperiod may have had on sow milk yield.…”

Section: Discussionmentioning

confidence: 88%

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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A note on simulating the `observer effect' using constant photoperiod on nursery pigs

Cited by 11 publications

References 10 publications

Analyses of body weight patterns in growing pigs: a new view on body weight in pigs for frequent monitoring

Analyses of body weight patterns in growing pigs: a new view on body weight in pigs for frequent monitoring

Diurnal changes of behavior and respiration of Yangtze finless porpoises (Neophocaena phocaenoides asiaeorientalis) in captivity

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

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