title: Structure and age-dependent development of the turkey liver: a comparative study of a highly selected meat-type and a wild-type turkey line.
abstract: In this study the macroscopic and microscopic structure of the liver of a fast growing, meat-type turkey line (British United turkeys BUT Big 6, n=25) and a wild-type turkey line (Wild Canadian turkey, n=48) were compared at the age of 4, 8, 12, 16, and 20 wk. Because the growth plates of long bones were still detectable in the 20-week-old wild-type turkeys, indicating immaturity, a group of 8 wild-type turkeys at the age of 24 wk was included in the original scope of the study. Over the term of the study, the body and liver weights of birds from the meat-type turkey line increased at a faster rate than those of the wild-type turkey line. However, the relative liver weight of the meat-type turkeys declined (from 2.7 to 0.9%) to a greater extent than that of the wild-type turkeys (from 2.8 to 1.9%), suggesting a mismatch in development between muscle weights and liver weights of the meat-type turkeys. Signs of high levels of fat storage in the liver were detected in both lines but were greater in the wild-type turkey line, suggesting a better feed conversion by the extreme-genotype birds i.e., meat-type birds. For the first time, this study presents morphologic data on the structure and arrangement of the lymphatic tissue within the healthy turkey liver, describing two different types of lymphatic aggregations within the liver parenchyma, i.e., aggregations with and without fibrous capsules. Despite differences during development, both adult meat-type and adult wild-type turkeys had similar numbers of lymphatic aggregations.
authors.affiliation: Institute of Veterinary Anatomy, Department of Veterinary Medicine, Freie Universität Berlin, Koserstraße 20, 14195 Berlin, Germany.
authors.forename: Hana
authors.initials: H
authors.lastname: Hünigen
authors.affiliation: Institute of Veterinary Anatomy, Department of Veterinary Medicine, Freie Universität Berlin, Koserstraße 20, 14195 Berlin, Germany.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Mainzer
authors.affiliation: Institute of Veterinary Anatomy, Department of Veterinary Medicine, Freie Universität Berlin, Koserstraße 20, 14195 Berlin, Germany.
authors.forename: Ruth M
authors.initials: RM
authors.lastname: Hirschberg
authors.affiliation: Institute of Veterinary Anatomy, Department of Veterinary Medicine, Freie Universität Berlin, Koserstraße 20, 14195 Berlin, Germany.
authors.forename: Pia
authors.initials: P
authors.lastname: Custodis
authors.affiliation: Institute of Veterinary Anatomy, Department of Veterinary Medicine, Freie Universität Berlin, Koserstraße 20, 14195 Berlin, Germany.
authors.forename: Ole
authors.initials: O
authors.lastname: Gemeinhardt
authors.affiliation: Institute of Veterinary Anatomy, Department of Veterinary Medicine, Freie Universität Berlin, Koserstraße 20, 14195 Berlin, Germany.
authors.forename: Salah
authors.initials: S
authors.lastname: Al Masri
authors.affiliation: College of Veterinary Medicine, School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia.
authors.forename: Kenneth C
authors.initials: KC
authors.lastname: Richardson
authors.affiliation: Institute of Poultry Diseases, Faculty of Veterinary Medicine, Freie Universität Berlin, Königsweg 63, 14163 Berlin, Germany.
authors.forename: Hafez Mohamed
authors.initials: HM
authors.lastname: Hafez
authors.affiliation: Institute of Veterinary Anatomy, Department of Veterinary Medicine, Freie Universität Berlin, Koserstraße 20, 14195 Berlin, Germany Johanna.Plendl@fu-berlin.de.
authors.forename: Johanna
authors.initials: J
authors.lastname: Plendl
mesh_terms: D000367:Age Factors; D000822:Animal Husbandry; D000818:Animals; D005260:Female; D008099:Liver / Q000033:anatomy & histology* / Q000254:growth & development / Q000378:metabolism*; D008297:Male; D009929:Organ Size; D012641:Selection, Genetic; D014422:Turkeys / Q000033:anatomy & histology* / Q000235:genetics / Q000254:growth & development / Q000502:physiology*
keywords: BUT Big 6; liver; lymphatic aggregation; morphology; wild turkey line