Record Details
Field | Value |
---|---|
Title | Absorption and metabolism of iron as related to the cotton fur syndrome in mink |
Names |
Bailey, David Eugene
(creator) Stout, F. M. (advisor) |
Date Issued | 1966-06-30 (iso8601) |
Note | Graduation date: 1967 |
Abstract | "Cotton fur" (CF) in mink (Mustela vison) is characterized by lack of pigment in the underfur of dark mink and is part of a syndrome including hypochromic, microcytic anemia and substandard growth, resulting from an iron deficiency. Such symptoms are produced by feeding rations containing raw Pacific hake (Merluccius productus), even though the ration contains adequate iron. The research reported herein concerns two phases of the CF abnormality; first a study using purifed diets to determine if iron deficiency per se results in failure of pigment formation, and second, studies of iron metabolism using ⁵⁹Fe as a tracer to determine why iron is not utilized by mink fed hake-containing rations. Standard dark mink kits were fed either a basal iron-deficient diet or the basal diet with 15 ppm of added iron. Chemical analysis of the diets showed that they contained 4.6 and 19.7 ppm of iron, respectively. Blood data illustrated that a hypochromic, microcytic anemia was present in those animals receiving the iron-deficient diet. After the winter furring cycle, all mink on the deficient diet exhibited unpigmented underfur and those receiving the adequate diet had normally pigmented underfur; establishing the necessity of iron as a chromotrichial nutrient. In a subsequent trial four groups of mink received purified diets with 0, 5, 10, and 15 ppm of added iron. Results supported those of the previous one, with 75 and 33 percent CF incidence in the 0 and 5 ppm groups respectively, and no CF in either the 10 or 15 ppm groups. Limited data showed that 70 percent of the ⁵⁹Fe present in mink hair was located in the melanin granule, indicating that iron may be an integral part of the melanin molecule. Eight trials involving 37 individual iron balance trials were conducted using ⁵⁹Fe to provide information on the second objective. ⁵⁹Fe was administered in feed or stomach tubed and iron absorption was determined from blood and excretory data. Ferrous citrate-⁵⁹Fe was given in either raw Pacific hake or sole based rations. From blood data, iron absorption was 1.4 percent for the raw hake-fed mink versus 11.2 percent for mink receiving sole. Due to uncontrollable fecal ⁵⁹Fe contamination of urine, plasma radioactivity was used to determine if the iron was being absorbed and excreted in the urine, To ensure complete ingestion of the tracer dose, mink were stomach tubed with ⁵⁹Fe in a water filtrate of hake, and controls received the radioisotope in distilled water. Iron absorption was greater (16.3%) in presence of raw hake filtrate than with distilled water (11.6%). Mink fed raw hake containing rations absorbed 7.5 percent and those fed rations of cooked hake absorbed 6.7 percent of the ⁵⁹Fe given. ⁵⁹FeSO₄ was given in cooked and raw hake suspensions and iron absorption was 23.2 percent for the cooked hake and less (12.3%) for raw hake with iron added immediately, as compared to 15.9 percent for iron allowed to incubate with raw hake. ⁵⁹Fe-hemoglobin was adminstered in cooked and raw hake suspensions and absorption of iron was completely stopped in the mink given raw hake, but only lowered (5.2%) in those given cooked hake. ⁵⁹FeCl₃ was given with cooked and raw hake suspensions. Mink receiving cooked hake absorbed 16.6 percent and those receiving raw hake absorbed only 2.9 percent, suggesting that the factor present in raw hake specifically interferes with the utilization of ferric iron. Form of iron, presence of other feedstuffs, and length of incubation of added iron were found to influence the utilization of iron in presence or absence of raw hake. ⁵⁹Fe activity of blood components indicate that in every case where iron utilization is impaired by the presence of raw hake, interference is at the absorptive level. Time of feed passage through the gastrointestinal tract as determined by excretion of radioactive iron for the 37 observations made was 185±22 minutes with a range of 59-360 minutes. |
Genre | Thesis/Dissertation |
Topic | Iron -- Metabolism |
Identifier | http://hdl.handle.net/1957/47917 |