Iodine nutrition in ewes: effects of low to high iodine intake on iodine content of biological fluids in pregnant and lactating ewes

Blood Trace Element Status in Camels: A Review

Trace minerals play an important role in animal health and productivity. They are involved also in many physiological activities, and their deficiency causes a variety of pathological problems and metabolic defects, reducing consequently the animal productivity. The demand for animal products in semi-arid areas is rapidly increasing, and the supply is still below the required level, partially due to low animal productivity. Camels (Camelus dromedarius and Camelus bactrianus) are considered one of the main sources of healthy, high-quality meat and milk for human consumption within most of the countries in the semi-arid regions. Despite their efficient adaptation to their environment, camels can suffer from the growth retardation of newborns, low feed efficiency, anemia, poor fertility, poor reproduction and many other metabolic disorders. It is well known that trace mineral deficiencies and trace mineral toxicities can influence camels' production and reproductive efficiency, as well as many aspects of their growth and metabolism. Evaluating the trace minerals status of camels and their variability is an obvious step toward improving camels' productivity and health. Thus, the present article reviews the data regarding the status of trace minerals (copper, zinc, iron, selenium, manganese, cobalt, iodine, fluorine, molybdenum, sulfur, bromide and nickel) in camel blood and their physiological variability, with a focus on their deficiency and toxicity effects.

Effect of the level of iodine in the diet of pregnant ewes on the concentration of immunoglobulin G in the plasma of neonatal lambs following the consumption of colostrum

Excessive I in the diet of pregnant sheep can reduce the concentration of antibodies in the blood plasma of the lambs after they have consumed colostrum. Our aim was to determine the dose of dietary I that would avoid this effect, and to relate this to changes in the concentrations of hormones and metabolites in the lambs. Four groups of pregnant ewes received concentrate containing 5·5, 9·9, 14·8, and 21·0 mg I/kg DM, respectively. Hay and molasses (containing 0·16 and 0·29 mg I/kg DM, respectively) were available ad libitum. The lambs were prevented from suckling for the first 24 h of life and were fed a fixed quantity of artificial colostrum in four feeds. At 24 h, the average plasma concentrations of immunoglobulin G in the lambs were 6·08, 5·06, 3·18 and 3·10 g/l for the 5·5, 9·9, 14·8 and 21·0 mg/kg groups, respectively. Supplementation with I was associated with higher levels of tri-iodothyronine and thyroxine in the lambs at birth. There was no effect of treatment on the plasma concentrations of insulin, cortisol, glucose or NEFA in the lambs. The concentration of dietary I that had an effect on the immunoglobulin concentration in the lambs is marginally above the levels added to commercial concentrate feeds; we tentatively identify 9·9 mg I/kg DM (approximately 9 mg I/ewe per day) as the upper safe limit of I supplementation according to the criterion of the concentration of immunoglobulin G in the plasma of lambs at 24 h after birth.

Trace-elements status in camels. A review

Data relating to trace-elements status in camels is scarce, from both a clinical and biochemical point of view. Clinical deficiency or toxicity has rarely been described in this species. However, there is a some evidence that camels are sensitive to trace element disorders in the same way as other ruminants. For example, copper deficiency in camels has been reported in East Africa. Normal plasma level is comparable to cattle (70-120 mg/100 mL). Camels appear to maintain zinc levels at a lower value than other domestic ruminants (< 60 micrograms/100 mL). Iron metabolism is more active in the liver than in the spleen. Data concerning manganese levels are possibly unreliable. Some cases of selenium deficiency (white muscle disease) have been reported. No data are available for cobalt status in camels. Finally, camels appear to be more sensitive to iodine deficiency than the other domestic ruminants.