Research Description:

Mineral Status of Beef Cattle in Northwest Florida, Emphasizing Magnesium

Mineral imbalances (deficiencies or excesses) in soil and forages have long been held responsible for low production and reproductive problems among grazing ruminants. The majority of Florida soils and forages are more deficient in required minerals for cattle than for any other state. Reported mineral deficiencies for cattle in Florida include phosphorus, calcium, magnesium, salt, cobalt, copper, iron, selenium and zinc, as well as toxicities of molybdenum and fluorine.

Grass tetany is a devastating disease in older beef cattle that occurs due to a lack of magnesium. Mortality rate is high and it is often associated with cattle grazing small grain forages (e.g. rye grass and oats) in the spring. Grass tetany incidence is most common in the panhandle of Florida and last year was a problem in the Marianna region. Pastures conducive to grass tetany are low in concentrations of magnesium, as well as elevated concentrations of potassium and nitrogen.

The objective of my experiment is to determine the potential for grass tetany in the panhandle of Florida by evaluating magnesium concentrations in blood plasma and urine and forage concentrations of magnesium, potassium and nitrogen and to evaluate the overall mineral status of cattle and forages based on concentrations of minerals in blood plasma and forages.

Samples were collected bi-weekly for a total of six collections during the time grass tetany incidence is most severe. Statistical comparisons as to mineral concentrations will be compared by collection dates. The statistical model will compare the three forage species and the two animal breeds.