When the pocketbook gets thin sometimes the first thing to get scrimped is the livestock’s diet. We glean a little bit more from the hay, a little bit more from the field, and supplementing becomes less of a priority. Whether it’s time or money that’s running low, how long can the cattle really go, lacking some of those essential nutrients, and still produce?
Dona Funk, livestock specialist with the University of Missouri Extension, answers some of these questions.
Micronutrient needs of cattle
“Many cattle producers know that there are several minerals that their cattle need like calcium, phosphorus and sodium. There are also several other minerals that cattle need in smaller doses, trace minerals or microminerals, that are as essential to the health and performance of an animal. These include iron, zinc, manganese, copper, iodine, cobalt and selenium.”
Supplementing in a cost-efficient way
“Many of these mineral are supplemented through a free-choice mineral but that may not be the most cost-effective way. In order to ensure that each animal is receiving the proper amount, a trace mineral supplement can be added to a complete mixed ration or a supplement. This allows each animal to consume the needed amount without overconsumption, as long as there is adequate bunk space to allow each animal to consume the feed. Trace mineral supplementation can also be done using a self-feeding mineral free-choice but some animals will over consume the supplement while other will eat less than they need. Salt or highly palatable concentrates are usually added to these systems to encourage supplement intake, which increases cost."
Results of not having the correct micronutrients
"For example, copper deficiencies are fairly common among Arkansas cattle that consume forages as a major portion of their diet. A copper deficiency can cause weight loss, bleaching of the hair coat and anemia. In regions of the state where vegetation supplies less than 5 ppm of copper, adult beef animals occasionally suffer from falling disease, sudden death due to heart failure and anemia. Another trace mineral, cobalt, is required for synthesis of vitamin B12 by ruminal bacteria. A cobalt deficiency can cause a decrease in appetite, followed by muscle wasting and anemia. Cobalt supplementation is important for beef cows wintered on low-quality roughages of all types. Most tall fescue hay samples collected in the Ozarks are marginal or deficient in cobalt."
How much phosphorus – one of the most expensive required minerals – does a grazing cow need this summer?
"A phosphorus deficiency will result in decreased animal performance including weight gains, reproductive efficiency and low milk production. Calcium and phosphorus have a mutual role in bone metabolism and supplementation of each should be considered together. A good calcium to phosphorus ratio in cattle diets in 2:1 to 1.2:1. Deviation from this ration can result in abnormal bone growth or urinary calculi."
