Mineral balance important to cow performance
Feeding of corn co-products like distillers grains and corn gluten has changed the mineral balance in winter cattle diets, said Dennis Bauer, Brown County Extension Educator.
Those products are really high in phosphorus, Bauer said. When ranchers begin feeding two to three pounds of these co-products, they might be able to discontinue phosphorus supplementation completely and just feed salt with a little bit of copper and zinc.
To thrive, cattle need several minerals in their diets, especially during winter when feed sources aren't quite as nutritious, Bauer said.
Deficiencies of phosphorus, copper and zinc are of primary concern, he said, as is the ratio between phosphorus and calcium. Without these minerals and several others, cattle don't perform as well as producers might expect.
More severe shortages or imbalances of these minerals can disrupt reproductive health resulting in a few more open cows, Bauer said.
During a three-year study conducted between 2001 and 2003, UNL researchers tested about 1,000 samples of winter forages, including a lot of meadow hay. For the most part, meadow hay proved to be a good source of calcium, although it was a bit deficient in phosphorus, copper and zinc.
Alfalfa is the best source of all the minerals, except it's a little short of copper and zinc. But, Bauer said, most producers don't provide a full feed of alfalfa, so the cow's requirements still may not be met. He did not recommend a full feeding of alfalfa because that would mean overfeeding protein.
Instead, he encouraged ranchers to test their forage. Find out what minerals are in the forages during the winter. They can give credit for the minerals those forages contribute and balance the ration with a mineral package.
Mineral balance in a cow's winter ration can make the difference between good and substandard performance.