cows in field

Recent Odairy Discussion, July 2019

A number of producers were recently puzzled by the unusually low MUN (milk urea nitrogen) levels in their milk. Farmers often have the testing done to give them information to help decide when to adjust the protein in dairy rations. Even the experts disagree what level is the healthiest for dairy cows, but it is usually accepted that 8 to 14 mg/dl is a healthy range. Typically, MUNs can run quite high in the early pasture season, so when a grazier saw levels of 2 to 4, he wondered why.

Other farmers shared that they were seeing similar numbers in their milk this spring. Most producers blamed the unusual wet and cool weather for the change in the pasture forages. According to some soil experts on the list, the excessively wet conditions set the stage for denitrification, where the roots are unable to take up enough nitrogen to supply the plants needs to make proteins. “ Excessively wet soil combine with warm spring temperatures leads to a much higher rate of denitrification than in a drier spring. Also the higher the pH the faster the rate of denitrification. N losses can commonly be 20-40% or even higher if all of the conditions for optimum denitrification occur.” One specialist suggested the addition of a nitrogen source such as Chilean nitrate in early spring would help, but another cautioned that too much applied could lead to nitrate poisoning.

After recently renting some new pasture land, the farmer realized it has a lot of burdock in it. He asked the list if it was safe to graze. Several producers replied that cattle like to graze burdock when it is young, but tend to avoid it when it gets mature. One producer recommended that when grazing any “weed”, it is important that you not force animals to eat them, so arrange paddocks in a way that animals are also offered other quality forages. A wise producer also reminded us that it is critical to mow the burdock before it goes to seed and sets up those pesky burs. “We tend to get burdock in "sacrifice" areas where we've put cows during winter or extremely muddy pasture conditions. Common Burdock has a deep tap root, so is good for cycling minerals from the subsoil and busting through hard pan. According to Agri-Dynamics, the relative feed value of burdock is higher than alfalfa.” Another farmer reminded us that burdock tincture is a common remedy for fatty liver/ketosis.

A farmer asked the group their experiences using washable cloths instead of disposable paper towels. None of the respondents indicated that there was an increase in mastitis or SCC when they gave up the paper towels. Most farmers said they preferred microfiber towels since they cleaned the cows so much better, especially when conditions were muddy. Farmers recommended a few sources of the microfiber towels: Maxim Mart Textile Products (online), Menards (in the Midwest), and IBA.