Salt as a management tool to enhance rotational grazing

Oct 1, 2007 12:00 PM

By Larry Berger, University of Illinois for the Salt Institute

With rapidly increasing grain prices there is renewed interest in optimizing beef production from grazing systems. Rotational grazing, sometimes referred to as management-intensive grazing (MiG), can increase beef production per acre by 30% compared to traditional grazing methods.

The most common form of rotational grazing requires large pastures to be subdivided into smaller paddocks. These paddocks are grazed for two to four days, and then the cattle are rotated to a new paddock. Often, 10 or more paddocks are involved so that grazing occurs at roughly 30-day intervals.

The Benefits

Besides the increased beef production per acre, there are several ecological benefits from properly managed rotational grazing systems.

First, more-uniform grazing prevents bare spots that often result from localized grazing. When more than adequate forage is available, cattle will often graze some areas very close because the regrowth is more succulent and less fibrous compared to plants that have been allowed to mature because they were not grazed.

In most rotational grazing systems, the cattle will be moved when the forages have been grazed to a height of 2-3 inches (in.). This reduces wind and water erosion by maintaining a uniform forage cover.

With rotational grazing, the feces and urine are more evenly distributed across the paddock, rather than being concentrated in resting areas as often occurs with traditional grazing methods. This improves nutrient recycling and increases forage production.

Salt and Ionophores

Cattle grazing lush forages have an increased appetite for salt. Grazing cattle will usually consume twice as much salt as those fed high-concentrate diets. Part of the explanation may be that lush forages are generally high in potassium (K) and low in sodium (Na).

The body has to maintain a sodium potassium balance, which may stimulate salt intake. Salt is an excellent means of delivering ionophores to grazing cattle.

The ionophore monensin, marketed as Rumensin,® is cleared as a feed additive to increase daily gain of grazing cattle. In the studies reported by Muller (1986), self-feeding a salt-monensin-supplement gave the same improvement in daily gain [0.2 pounds (lb.) per day] as hand-feeding the monensin supplement without salt. These data show that salt, an already proven intake regulator, can be made even better when combined with monensin.

Although less data are available with lasalocid, a Georgia study showed that lasalocid fed in a free-choice salt and mineral mix increased the gains of replacement heifers, cows and calves (Kiser et al, 1986).

Salt Feeders

Trace mineralized salt-mineral mixtures should be formulated to supplement the existing forages and to meet the nutrient needs of the cattle. Working with a nutritionist who understands the complexities of the soil-forage-animal complex is the best way to ensure that optimum nutrition is available to the animals.

Continued on next page...

Subscribe to American Cowman Update e-newsletter!

Breaking industry news in your e-mail inbox every other week!
Subscribe at http://subscribe.americancowman.com/subscribe.cfm.