Basing Turkey Lighting Programs on Broiler Research: A Good Idea? A Comparison of 18 Daylength Effects on Broiler and Turkey Welfare

Abstract

Simple SummaryAltering daylength in a poultry management program is a simple tool that can have immense impacts on productivity and bird welfare. It is not uncommon for lighting data derived from broiler research to be extrapolated to turkey production. This review of two studies (one with broilers and the second with turkeys), completed in the same research facility using the same lighting programs, shows evidence that some, but not all responses to graded daylengths are similar between these two species. It defines that daylength choices for turkeys should be based on research conducted with turkeys.AbstractDaylength used as a management tool has powerful implications on the welfare of both broilers and turkeys. Near-constant light results in many detrimental impacts, including lack of behavioural rhythms and circadian melatonin rhythms. Both are suggestive that sleep fragmentation could result in birds reared on long photoperiods, which can lead to the same negative health and physiological responses as total sleep deprivation. An indirect comparison of the welfare implications of graded levels of daylength on broilers and turkeys clearly indicate that long daylengths depress welfare by increasing mortality, reducing mobility, increasing ocular pathologies and changing behaviour in both species. Furthermore, long daylengths change melatonin secretion patterns and eliminate behavioural and melatonin circadian rhythms, which were measured in broilers in these works. However, feather pecking in turkeys was reduced when birds were exposed to long daylengths. Exactly how much darkness should be included in a management program to maximize welfare will depend on the species, the age of marketing, and in turkeys, bird gender.

Diurnal Rhythm of Plasma Melatonin Concentration in the Domestic Turkey and Its Regulation by Light and Endogenous Oscillators

“…These findings have important practical aspects, considering the significance of the domestic turkey as meat-producing animal. Schwean-Lardner et al [49] exposed turkeys to different cycles with varying periods of darkness and studied body weight, feed efficiency, skeletal disorders, mortality, mobility, and ocular measures, in birds. Most of these factors achieved their best results in cycles with the shortest days.…”

The length of the feed restriction period affects eating behavior, growth performance, and the development of the proximal part of the gastrointestinal tract of young broilers

“…Fasting procedures based on manipulating the light program are easier to implement and manage than physical restriction of the access to feed. Consequently, controlling light programs has been the preferred method to control FI in previous research studies ( Buyse et al., 1996 , Schwean-Lardner et al., 2013 , Schwean-Lardner et al, 2016 ). Limited information is available on the effects of physical restriction to access to feed, while maintaining the light program unchanged, on the development of the proximal part of the GIT of birds.…”

Effects of Light Regimens and Vitamin D3 Levels and Their Interactions on Broilers Growth Performance and Carcass Traits

“…In studies of Schwean-Lardner et al, (2016), Yang et al, (2015) and Aviagen (2014), improved feed conversion efficiency was observed in birds subjected to split darkness when compared to the continuous light group. Intermittent feeding and lighting have been used to improve feed efficiency (Farghly and Hassanien, 2012;Farghly and Makled, 2015).…”

“…Metwally et al, (2015) reported that light type significantly affected carcass traits. In studies of Schwean-Lardner et al, (2016). Olanrewaju et al, (2012) Indicated that long/continuous and regular/intermittent photoperiod equally improved broiler carcass characteristics compared with short/non-intermittent photoperiod.…”