title: Deposition of carotenoids in egg yolk by short-term supplement of coloured carrot (Daucus carota) varieties as forage material for egg-laying hens.
abstract: BACKGROUND
  Supplying egg-laying hens with different forage materials may influence egg production and quality. The aim of this study was to examine the short-term effects of standard feed plus 70 g day(-1) per hen of three coloured carrot varieties (orange, yellow and purple) as forage material in comparison with a standard feed control on egg production, egg yolk colour and deposition of carotenoids in the yolk.
  
  
  RESULTS
  Carrot supplementation reduced feed intakes significantly, but not on a dry matter basis. Orange carrot treatment significantly reduced egg mass production, whereas yellow and purple carrot treatments did not differ from the control. Egg and yolk weights of all carrot-supplemented treatments were significantly lower than those of the control, but yolk percentages were similar. Yolk redness increased significantly in the order control < yellow < orange < purple. A similar trend was seen for yolk yellowness, but yellow and orange carrots reached the same level. Yolk colour and carotenoid contents correlated positively and significantly. In particular, purple carrot treatment increased the yolk content of lutein (>1.5-fold) and beta-carotene (>100-fold) compared with the control.
  
  
  CONCLUSIONS
  Supplementing the feed of egg-laying hens with coloured carrots efficiently increased yolk colour parameters and carotenoid contents, which gives opportunities for improved nutritional value of eggs from forage material-supplemented hens.
authors.affiliation: Department of Food Science, Faculty of Agricultural Sciences, Aarhus University, DK-8830 Tjele, Denmark. marianne.hammershoj@agrsci.dk
authors.forename: Marianne
authors.initials: M
authors.lastname: Hammershøj
authors.forename: Ulla
authors.initials: U
authors.lastname: Kidmose
authors.forename: Sanna
authors.initials: S
authors.lastname: Steenfeldt
mesh_terms: D000821:Animal Feed; D000818:Animals; D002338:Carotenoids / Q000378:metabolism*; D002645:Chickens / Q000378:metabolism*; D003116:Color; D018552:Daucus carota; D019587:Dietary Supplements; D004530:Egg Yolk / Q000378:metabolism*; D004531:Eggs / Q000592:standards; D002149:Energy Intake; D005260:Female; D014975:Lutein / Q000378:metabolism; D018517:Plant Roots; D019207:beta Carotene / Q000378:metabolism
chemical_list: D019207:beta Carotene; D002338:Carotenoids; D014975:Lutein