Iron and copper availability from various sources.

A total of 1110 broiler cockerels were used in three experiments to determine the availability of iron and copper from various sources. A skim milk basal diet was fed in each experiment using chicks maintained in battery brooders beginning at one day of age. Four organic iron compounds (sequestered iron A' and ferric choline chloride in Experiment 1 and sequestered iron B and C in Experiment 2), ferrous sulfate and ferric oxide were the test iron compounds used in Experiments 1 and 2. Added dietary iron levels furnished by the test compounds were 10 and 20 p.p.m. (Experiment 1) and 5 and 10 p.p.m. (Experiment 2). The test copper compounds fed in Experiment 3 were added to furnish 1 and 2 p.p.m. copper using cupric sulfate, cuprous oxide and cuprous iodide. No consistent differences in hemoglobin content, hematocrit (packed cell volume), chick weight and mortality were observed between ferrous sulfate and the four organic iron compounds; however, these compounds were significantly superior to ferric oxide. Hemoglobin content, hematocrit and liver copper content were significantly increased when cupric sulfate was fed as compared to results obtained with cuprous iodide or cuprous oxide. Increased chick weight gain and decreased mortality were observed with chicks fed cupric sulfate or cuprous iodide as compared to those fed cuprous oxide. Chick availability values for ferric oxide (71 and 82%) were approximately three-quarters that of ferrous sulfate. The organic sources of iron gave high availability values (91-131%), although ferric choline chloride was not as available to the chick as the sequestered iron compounds (93-131%) as determined by regression analysis method and relative biological availability. Cuprous iodide and cuprous oxide have essentially equal availability, but the availability of these copper sources is only three-quarters that of cupric sulfate. POULTRY SCIENCE 53: 1325-1330, 1974 compare various inorganic forms of iron and copper commonly used in the poultry industry. These workers concluded the sulfate forms of iron and copper were superior to either the oxide or the carbonate form as measured by hemoglobin content and hematocrit (packed cell volume). Also, Fritz et al. (1970) found that the relative biological value of ferric oxide is considerably lower than that of ferrous sulfate for chicks. Nelson and Walker (1964) demonstrated a regression analysis technique used for biological evaluation of phosphate compounds. A similar method was used by Shah and Belonje (1973) for assessing iron availability. Also, Pla and Fritz (1971) proposed a relative biological availability procedure in which a comparison of iron from various supplements is made INTRODUCTION I and copper have received moderate attention in the literature in recent years. Fritz (1970) reported the need for attention of dietary iron in feed formulations. He, also, reported that care must be used in selection of supplemental iron sources that are biologically available. Elvehjem and Hart (1929) clearly demonstrated that anemia in chickens fed a milk diet could not be corrected with ferric oxide, but the feeding of ferric chloride or ferrous sulfate resulted in an immediate hemoglobin synthesis. Also, Willingham and Hill (1970) conducted an experiment to 1. Ocean Labs., Inc., Irvine. Calif. 92664 2. Naremco, Inc., Springfield, Mo. 65805 1325 at Pultry Sence A ssoiation M em er on July 6, 2015 http://ps.rdjournals.org/ D ow nladed from 1326 MCNAUGHTON, DAY, DILWORTH AND LOTT TABLE 1.—Composition of semi-purified basal diets used in all experiments Ingredient Percent Dried skim milk 63.00 Starch 15.38 Mineral premix 6.07 Vitamin premix 1.00 Vegetable oil 10.00 DL-methionine 0.30 Glycine 0.50 L-arginine-HCl 0.50 Choline chloride (70%) 0.20 Butylated hydroxy toluene (25%) 0.05 Alpha eel 3.00 'The mineral premix provided the following reagent minerals in g./kg. of diet: CaC03, 25.73; K2HP04, 11.20; NaCl, 6.0; MgS04> 2.50; ZnCO,, 0.18; MnSCyH20, 1.51; CuS04-5H20, 0.015; KI, 0.04; and Na2MoO4-2H20, 0.0025. 2 The vitamin premix provided the following amounts of vitamins per kg. of diet: (in milligrams) riboflavin, 9; thiamin-HCl, 6; Ca d-pantothenate, 20; niacin, 50; pyridoxineHCl, 8; folic acid, 2; biotin, 0.2; menadione sodium bisulfate, 2; inositol, 100; vitamin B12, 20 M-g-; vitamin A, 25,000 U.S.P. units; vitamin D3, 1200 I.C.U.; and Vitamin E, 17.6 I.U. CuSCy5H20 was excluded in Experiment 3. The added cobalt content was maintained at 0.6 p.p.m. in all experiments. This was in addition to cobalt present in vitamin B12. to that of iron from a highly available source such as ferrous sulfate. Much concern is expressed to find a more economical and more biologically available form of iron and copper than the established reference compounds, ferrous sulfate and cupric sulfate. Although the initial economic aspects of iron and copper feed grade supplements are not important, the availability of these compounds is important when considering the chance of deficiencies occurring. The experiments reported herein were conducted to evaluate the availability of iron and copper from various sources. MATERIALS AND METHODS Broiler strain cockerels obtained from a commercial hatchery were used in three experiments. At one day of age the chicks were wingbanded and randomly assigned to decks with raised wire floors in electrically heated battery brooders. Test diets and distilled water were furnished ad libitum in each experiment. Composition of the skim milk basal diet used in all three experiments is shown in Table 1. Copper and cobalt content were held constant in all diets in Experiments 1 and 2 at 2 p.p.m. copper and 0.6 p.p.m. cobalt. The cobalt added was in addition to cobalt found in vitamin B12 to avoid cobalt deficiency. In Experiment 3, iron and cobalt were held constant in all diets at 80 and 2 p.p.m., respectively. Cupric sulfate was excluded from the skim milk basal diet in Experiment 3. Test materials were added to the skim milk basal diet in the quantities indicated in each summary table. In Experiment 1, two commercial organic iron compounds (ferric choline chloride and sequestered iron A), ferrous sulfate and ferric oxide were fed to chicks to furnish 10 and 20 p.p.m. added dietary iron. Each diet was fed to triplicate lots of 10 broiler cockerels for a three week test beginning at one day of age. Two organic iron compounds (sequestered iron B and C) and ferrous sulfate were the test iron compounds used in Experiment 2. Added dietary iron levels furnished by the test compounds were 5 and 10 p.p.m. Each diet was fed to quadruplicate lots of 10 broiler cockerels for a four week test beginning at one day of age. Copper compounds tested in Experiment 3 were added to furnish 1 and 2 p.p.m. copper using cupric sulfate, cuprous oxide and cuprous iodide as the test compounds. Each diet was fed to quadruplicate lots of 20 broiler cockerels beginning at one day of age. Blood was taken for hemoglobin content and hematocrit analysis from five birds per lot per dietary treatment at 21 days of age in Experiment 1 and 3; and in Experiment at Pultry Sence A ssoiation M em er on July 6, 2015 http://ps.rdjournals.org/ D ow nladed from F E AND CU AVAILABILITY 1327 TABLE 2.—Composite data showing the effect of organic and inorganic iron compounds on hemoglobin content, packed cell volume (hematocrit) and chick weight (21 days of age) fed at 10 and 20 p.p.m. added iron (Experiment 1) Additive None Ferric choline chloride FeS04 FeO Sequestered Iron A Hemoglobin, g. 10 p.p.m. —