title: Choice feeding of selenium-deficient laying hens affects diet selection, selenium intake and body weight.
abstract: Inadequate selenium (Se) supply often in combination with low vitamin E status causes deficiency symptoms in many species. It is likely that a vague discomfort or sickness is perceived before clear deficiency signs become apparent. We investigated whether Se-deficient hens reduce their Se deficit by selecting a diet containing more selenium when offered two diets with different Se concentrations. A Low-Se diet (0.07 mg Se/kg) was supplemented with Se-enriched yeast (Sel-Plex 50) to produce Medium-Se (0.20 mg Se/kg) and High-Se (1.50 mg Se/kg) diets. Each of two consecutive study parts (I and II) with the same hens and treatments began with a 6-wk baseline period (Medium-Se diet), subsequently followed a 9-wk depletion period (Low-Se diet or Medium-Se diet), then a 6-wk choice feeding period in which two diets with different Se concentrations (Low-Se and Medium-Se, Medium-Se and High-Se, or Low-Se and High-Se) were offered. A control group received the Medium-Se diet throughout the study. Daily Se intake, calculated from daily feed intake, followed similar patterns in both parts of the study, but Se-deficient hens preferred (P < 0.05) the High-Se diet to the Low-Se diet during the first 3 wk of choice feeding only in part I. We conclude that young Se-deficient laying hens reduce their Se deficit if they have a choice between a Low-Se and a High-Se diet by preferentially selecting the High-Se diet, possibly based on learned place preference and/or learned taste aversion to the Low-Se diet, presumably in response to discomfort due to Se-deficiency.
authors.affiliation: Swiss Federal Institute of Technology, Institute for Animal Sciences, Nutrition Biology, ETH-Zentrum, 8092 Zurich, Switzerland. christine.zuberbuehler@inw.agrl.ethz.ch
authors.forename: Christine A
authors.initials: CA
authors.lastname: Zuberbuehler
authors.forename: Ruth E
authors.initials: RE
authors.lastname: Messikommer
authors.forename: Caspar
authors.initials: C
authors.lastname: Wenk
mesh_terms: D000818:Animals; D001835:Body Weight; D002645:Chickens / Q000502:physiology*; D004435:Eating; D005260:Female; D005518:Food Preferences; D010058:Oviposition; D012643:Selenium / Q000008:administration & dosage* / Q000172:deficiency*; D012646:Self Administration / Q000662:veterinary; D013649:Taste
chemical_list: D012643:Selenium