UV‐light and dietary vitamin D and their effects on ionized calcium and 25‐OH‐D plasma concentrations in captive gentoo penguins (Pygoscelis papua)

Abstract

In this study, the effect of ultraviolet (UV) light and dietary vitamin D on calcium metabolism in permanently indoor-housed gentoo penguins (Pygoscelis papua) was investigated. The study consisted of three periods, each completed with blood samples to analyse plasma concentrations of 25-OH-D, 1,25-(OH) -D, ionized (iCa) and total calcium (tCa). During the first study period (D), animals were housed under routine conditions without UV-light and fed a diet of different fish species, supplemented with 1,000 IU vitamin D per animal and day. The following study period (Baseline) of 28-day duration consisted of the same diet without any vitamin D supplementation and without UV-light. During the study period (UVB) artificial UV-light was added for 3 weeks. The vitamin D content of fish was measured by high-performance liquid chromatography. It varied between fish species and between facilities, ranging from no measurable content in capelin (Mallotus villosus) to 7,340 IU vitamin D/kg original matter (OM) in herring (Clupea spp). The average dietary vitamin D content was 311 IU/kg OM at facility 1 and 6,325 IU/kg OM at facility 2, resulting in a vitamin D intake per animal and day without supplementation of 130 IU (25.5 IU/kg body weight BW) and 2,454 IU (438.2 IU/kg BW) respectively. The supplementation of vitamin D elevated significantly the plasma concentrations of 25-OH-D by an intraindividual difference of 15 (range -2 to 59) nmol/L and tCa by 0.1 (0.0-0.3) mmol/L only at facility 2. The exposure to UV-light raised the blood concentrations of tCa at facility 2 by 0.15 (0.1-0.2) mmol/L, and of iCa and tCa for females at facility 1 by 0.23 (0.13-0.41) mmol/L and 1.8 (1.1-2.5) mmol/L respectively. No significant influence of the study periods (D) and (UVB) was found for the concentrations of 1,25-(OH) -D at both facilities.

Application of Ultraviolet Light for Poultry Production: A Review of Impacts on Behavior, Physiology, and Production

“…The importance of UV supplementation is not limited to domestic poultry species but can play a role in the behavior, physiology, and welfare of other captive species including zoologically housed species (Ross et al, 2013;Drake et al, 2017;Tröndle et al, 2018) or laboratory model species such as the zebra finch or starling (Bennett et al, 1996;Maddocks et al, 2002). UV supplementation often has positive effects but there can be deleterious implications such as photo bleaching and compromised pro-inflammatory immune responses (Blount and Pike, 2012).…”