April 2018 Articles

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Minerals for Beef Cattle

Minerals for Beef Cattle— Minerals are an essential part of the diet of all animals and play a significant role in the well-being of a beef herd. Practically all metabolic functions of an animal require minerals. About 5 percent of the total body weight of an animal is comprised of minerals. Minerals are usually classified as 1) major and 2) minor or trace. The major or macro-minerals include calcium, phosphorous, sodium, potassium, magnesium, chorine and sulfur. These generally are required in relatively large amounts. The minor or trace minerals include manganese, copper, iron, zinc, selenium, iodine and cobalt. The terms “minor” or “trace” should not be thought of as an indication of lack of importance. Rather, these terms indicate relative amounts required in the diet of any animal. Since minerals affect general health and ability to grow and reproduce, beef cattle need to be fed supplementary minerals. Mineral deficiencies are commonly problems related to soil composition and the availability of soil nutrients to plants. In some areas, several minerals may need to be supplemented. In other areas, only a few may need to be provided. When making decisions about mineral supplementation strategies, first know the animal’s mineral needs. The mineral requirements of cattle are reported by the NRC (Nutritional Requirements of Beef Cattle). These requirements, given in Table 1, are expressed as a percent or mg/kg (ppm) of the diet. Producers can use these values to calculate an animal’s required daily mineral intake. The second step is to estimate the animal’s mineral consumption from all sources other than the mineral supplement. To accomplish this, an understanding of total feed and forage dry matter intake, mineral composition of the feed and forage, & mineral digestibility is important. Finally, provide for mineral deficiencies with an economical mineral supplementation strategy. Mineral Requirements and Maximum Tolerable Concentrations — NRC, 7th Revised Edition Cows — 1,200 Lb. mature weight producing 20 Lb. milk per day during lactation Mineral Unit Gestating Early Lactating MaximumTolerable Concentration Calcium % 0.21 0.30 — Chlorine % — — — Chromium mg/kg — — 1,000.00 Cobalt mg/kg 0.10 0.10 10.00 Copper mg/kg 10.00 10.00 100.00 Iodine mg/kg 0.50 0.50 50.00 Iron mg/kg 50.00 50.00 1,000.00 Magnesium % 0.12 0.20 0.40 Manganese mg/kg 40.00 40.00 1,000.00 Molybdenum mg/kg — — 5.00 Nickel mg/kg — — 50.00 Phosphorus % 0.15 0.19 — Potassium % 0.60 0.70 3.00 Selenium mg/kg 0.10 0.10 2.00 Sodium % 0.06-0.08 0.10 — Sulfur % 0.15 0.15 0.40 Zinc mg/kg 30.00 30.00 500.00 Although type of animal and reproductive status of an animal can influence mineral requirements, the previous table illustrates a general recommendation of mineral levels for beef cows. If mineral levels in the ration or forage fall below the suggested levels, deficiency symptoms will become evident. Specific symptoms for each mineral are possible, but many symptoms may be similar for several minerals. These may include loss of or an abnormal appetite, poor growth rate, poor reproductive performance, skeletal problems, dull and rough hair coat and an overall unthrifty condition. Levels of minerals above the maximum tolerable levels can result in toxic situations, generally resulting in eventual death. The most satisfactory way of providing supplemental minerals to animals is to use a “complete” mineral mixture (contains macro and trace-minerals) offered free choice in a single compartment feeder. The calcium to phosphorus ratio should be about 1.5-2:1 under most conditions in Louisiana. Alternatively, producers can choose to mix their own mineral mixtures or have special mixtures formulated based on the individual requirements of the beef herd. Regardless of the method of supplementation, it should meet the dietary requirements and be the most cost-effective method. Provide clean, fresh minerals continuously, and monitor consumption. Mineral intake should remain in the range of two to four ounces per head per day. Intake will vary because of the type and quality of forage and feed available. Place mineral feeders in areas readily accessible to cattle. Such areas include water tanks, shaded loafing areas and areas of best grazing. The number of feeders should be adequate to accommodate the maximum stocking rate of the pasture. Check feeders at least weekly to monitor intake and assure a clean, fresh supply of minerals. Overall productivity of a beef herd can be significantly affected by a deficient mineral supplementation program. Supplying beef cattle with adequate levels of both major and minor minerals is required to attain maximum productivity from your herd. An analysis of your mineral program may go a long way in solving several problems continuously encountered. — Source: LSU AgCenter publication 2239 “Louisiana Beef Cattle Production”.