For these additives to work effectively, it is critical cattle consume the targeted amount of these products regularly. Average intake should be monitored to determine whether any adjustments should be made.
An easy way to calculate consumption of loose mineral supplements is to wait until mineral feeders are empty or almost empty. If more than a couple of pounds of mineral is in the feeder, pour it into a bucket for later use. Then fill the empty mineral feeder with 50-pound sacks of mineral and record the number of sacks used.
Count the number of days it takes the herd to consume the mineral. Then divide the pounds of mineral put in the feeder by the number of days to get a daily herd average; divide this by the number of cattle in the herd to determine mineral consumption per cow per day. This same approach can also be used with molasses tubs or blocks.
As an example, if there are 40 cows in a herd, and the targeted intake is 4 ounces per cow per day, then the herd would need to consume 10 pounds per day or 70 pounds each week. If intake is less than the target, then additives are being underconsumed, which will reduce their effectiveness.
Location of mineral feeders or molasses tubs can affect consumption; moving these products closer to water sources or bedding areas will generally increase consumption. Additionally, mineral feeders that are more open in their design generally increase intake; however, these feeders may not provide as much protection from the weather.
Mineral formulation also has a significant impact on intake. Both phosphorus and magnesium reduce mineral palatability, and dropping their levels when appropriate will increase consumption. Salt initially encourages intake of loose mineral supplements but, as more is consumed, it will start to limit intake. If mineral consumption is low, check to make sure cattle are not receiving salt from other sources.
Molasses tubs and blocks generally are not affected by formulation as much.
Although underconsumption is generally the biggest challenge with these products, overconsumption can occur and results in increased costs. Monitoring intake is key to the successful use of these products. 
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Jason Banta
- Associate Professor and Extension Beef Cattle Specialist
- Texas A&M University
- Email Jason Banta
