Salt and Trace Minerals newsletter

The 2010 first quarter Salt and Trace Mineral newsletter explains the importance of chromium in animal nutrition as well as levels permitted.

STM-Summer 2009

The importance of proper nutrition for lactating dairy cows is shown to be most important prior to three weeks before calving and three weeks post-calving. As this is the most stressful time in a cow’s life, relevant research is reviewed and the beneficial effect of proper nutrition is presented in this newsletter.

Copper nutrition of livestock and poultry is complex. Cattle are susceptible to copper deficiency, sheep are prone to copper toxicity and pigs benefit from high levels of copper supplementation. The copper requirements of goats are more like that for cattle than sheep, and poultry do not show the same health benefits of high copper intakes observed in pigs. In addition antagonists, primarily sulfur, molybdenum and iron greatly affect the bioavailability of copper in ruminants. Increasing amounts of distillers grains are being included in livestock and poultry diets.

Grass tetany is a complex disease that causes significant economic losses for livestock producers every year. Like putting together a puzzle, more and more of the pieces are coming together so that we can understand the true causes of this disease. What we once thought was primarily a magnesium deficiency, is now recognized to be a combination of excess nitrates and potassium in combination with inadequate salt consumption. Increasing sodium consumption improves magnesium absorption and nitrate excretion, both keys to preventing grass tetany.

Larry L. Berger, Ph.D.

Salt Institute

Salt and Trace Minerals newsletter

Summer 2008 (Vol. 40, No. 3)

Every continent has areas where goiter in humans and livestock has been associated with iodine deficiency. A 1928 study found that feeding salt fortified with potassium iodide would prevent goiter in farm animals and iodized salt quickly achieved widespread use. In sheep, four factors can affect the supplemental iodine requirements: 1) the amount of iodine being consumed from feed, water, soil, etc., 2) the intake of dietary constituents, called goitrogens, which interfere with the thyroid gland’s ability to trap iodine and to convert it into thyroactive substances, 3) the presence of an adequate amount of selenium is required for proper iodine metabolism, and 4) environmental factors, such as cold stress, can increase the iodine requirement, since the rate of basal metabolism must increase to maintain core body temperature.

Larry L. Berger, Ph.D.

Salt Institute

Salt and Trace Minerals newsletter

Spring 2008 (Vol. 40, No. 2)

Salt is a proven intake limiter for grazing cattle. With the rapid expansion of the ethanol industry in the U.S. there is a plentiful supply of byproduct feeds, distillers grains, corn gluten feed, wheat midds, soy hulls and brewers grains. Because most of these byproducts are high in fiber and medium to low in protein, they are best suited to supplement high forage diets for ruminants. Hand feeding supplements is quite expensive, so producers need the most cost-effective self-limiting treatment. Options include a mixture with 16% salt, a mixture of 3% ammonium chloride and 2.25% ammonium sulfate, or 7% calcium hydroxide All are effective, but a recent two-year study found that steers fed the salt-limited supplement had gains that were equal to the hand-fed steers and 20 pounds per animal more than either the ammonium chloride-ammonium sulfate mixture or calcium hydroxide.

Larry L. Berger, Ph.D.

Salt Institute

Salt and Trace Minerals newsletter

Winter 2008 (Vol. 40, No. 1)

Sodium and chloride are essential for life and salt is an excellent source of these nutrients. Almost anything can become toxic at some level or under unique conditions, and salt is no exception. Water and/or salt deprivation are commonly associated with salt toxicity. The critical difference between a nutrient and a poison is quantity and circumstances under which it is consumed. An adequate supply of clean fresh water will almost guarantee that salt toxicity will not be a problem under normal management conditions. Water intake is critical because the kidney is the major organ which responds to excess sodium intake. Plasma concentrations of sodium are controlled by the hormone aldosterone, which controls the amount of sodium reabsorbed from the kidney tubule. The benefits of feeding a well-fortified trace mineralized salt far out weigh the risk of a salt toxicity.