Effect of iron source on performance, some minerals, thyroid hormones and blood metabolites of Mehraban male lambs

Iron is one of the essential trace elements for livestock, which is essential for the transport, storage and use of oxygen. Iron is one of the components of hemoglobin, myoglobin, transferrin, cytochromes and many enzymatic systems including catalase, peroxidase, phenylalanine and hydroxylase. Providing iron in the diet improves hematologic parameters and growth performances of calf and lamb. Also, the presence of iron in the diet is necessary for appetite, secretion of thyroid hormones and glucose metabolism. Recently compounds as nanoparticles using nanotechnology have been released. Changes in particle size to the nano-particle (size less than 100 nm) increase surface to volume ratio and change their other characteristics. Increasing the surface area of the nanoparticles allows their interactions with organic and inorganic molecules occur differently. One of these compounds is iron oxide nanoparticle which is used in various industrial fields and even as feed additive. Since the experiments and research on iron nanoparticles have not been carried out in the field of ruminant nutrition, so far this experiment was designed to evaluate the effect of two types of iron (nano iron oxide and iron sulfate) on performance (feed intake and average daily gain), plasma concentration of some minerals, thyroid hormones and hematological parameters of growing Mehraban lambs.
Material and In this experiment, 30 male lambs with 4 ± 0.5 months age and average live weight of 27.1 ± 1.51 kg in a completely randomized design were used for 60 days. The lambs were placed indoor in 2×1 meter individual cage with a cement floor and received water and feed individually and ad libitum. The treatments were: 1) basal diet (control), 2) basal diet 25 mg/kg iron as nanoparticles of iron oxide, 3) basal diet 50 mg/kg iron as nanoparticles of iron oxide, 4) basal diet 25 mg/kg iron as ferrous sulfate and 5) basal diet 50 mg/kg iron as ferrous sulfate. Diets were offered to the animals in the morning (8:00) and evening (16:00). In the beginning of the experiment, before morning feeding, lambs were weighed in two consecutive days with 16 hours feed and water deprivation and the average weight of these two days for each animal was considered as weight of day zero. Feed intake on a daily basis in every single lamb was measured. All lambs every 15 days (2 consecutive days) before morning feeding (with a 16-hour feed and water deprivation) were weighed to determine changes in body weight. On days 30 and 60 before the morning feeding, blood samples through the jugular vein were taken from all lambs. Immediately after blood collection, 0.5 ml of heparinized blood was poured into 1.5 ml micro tube and sent to a medical laboratory and using automatic cell counter, hematological parameters (number of red cell, concentration of hemoglobin and red cell percent) were determined. Plasma concentrations of iron, zinc and copper were determined using atomic absorption spectrometry and calcium and phosphorus were determined according to standard methods. Plasma concentrations of thyroid hormones (T3 and T4) were measured based on the immunological competitive enzyme assay using ELISA in accordance with relevant guidelines.
Dry matter intakes of iron supplemented treatments (treatments 2, 3, 4 and 5( were 1.32, 1.42, 1.36 and 1.39 kg/d, respectively, which were significantly higher than control (1.23 kg/d), (P In overall, the obtained results of this study showed that iron supplementation improved performance, blood iron and thyroid hormones concentrations in lambs. Also blood concentrations of iron and thyroid hormones in all the treatments were within the normal range. However concentrations of above mentioned compounds in control group were in down the ranges and in iron supplemented treatments were in top the ranges. Also no significant difference was observed between the two types of supplements for performance and thyroid hormones at the end of the period. But nano-iron supplement was more effective on hematological indices compared to ferrous sulfate.