What is milk urea nitrogen? Milk urea nitrogen (MUN), the concentration of urea in milk, is a tool to monitor the efficiency of crude protein utilization in dairy cows. In the rumen, microbes degrade dietary protein to ammonia. When ammonia is coupled with fermentable carbohydrates, rumen microbes are able to capture the nitrogen and synthesize amino acids and microbial protein. However, excess ammonia in the rumen is absorbed across the rumen wall and taken to the liver to be converted to urea. Blood urea is freely diffusible to milk, and therefore, MUN reflects the urea concentration in blood.

I have been home from Iraq now for two months. Taking some leave time – what we call decompression – and getting started in my new position at the Civilian Response Corps fills the days. And, of course, I am enjoying flying my Mooney airplane. As of this writing, it is sitting in a hanger in Willmar, Minnesota. During an annual inspection (which is required), an engine casing fracture was found, so the aircraft is grounded for six weeks while repairs are done. In this article, I comment on the Middle East region that has been my life the last four years. The news is mixed.

I was sitting on the beach reading the Malibu newspaper to acquaint myself with their local concerns. There were the usual stories; real estate, recession, anti-motorcycle rants, the Interior Secretary’s visit to the park, and the anti-rodenticide brigade. The second page had a story complete with photos of a very sick bobcat. One of the Valley Wildlife Care group diagnosed him as having “active rodenticide poisoning.” I called their number. The answering machine said they were too busy to handle “information calls” since they were deluged with people bringing in injured birds, mostly baby birds that had fallen from their nests. They require so much care. They reported that in order to save the anemic bobcat, a healthy bobcat donor had arrived from almost 200 miles away to administer a blood transfusion. The prognosis was “poor.”

There will be a financial incentive to increase milk sales available to each farm. Assuming milk sales increase over the previous year, an additional incentive will be paid for high-quality milk as measured by somatic cell count (SCC) for the herd. The SCC is the number of cells, primarily leukocytes, per milliliter in milk. Leukocytes, or white blood cells, are produced by the cow’s immune system to fight an inflammation in the mammary gland or mastitis – either clinical or sub-clinical. The SCC also increases during a myriad of stress conditions. Monitoring SCC is especially critical in diagnosing cows with subclinical mastitis, because no visible signs of an inflammation are observed by the dairy producer. That was the original intent of the California Mastitis Test that estimates SCC of individual cows by stripping milk into a four-part plastic paddle, adding the test solution and then swirling the contents to visually measure the gel formation.

The first 10 days following calving are critical to lactation success. Producers must help cows transition smoothly from the dry period and into early lactation high production. Cows in good body condition with adequate access to a properly balanced ration, and plenty of housing and cooling, will have the necessary foundation for a successful transition period. In addition to meeting critical transition needs, producers should develop protocols to manage fresh cows and identify signs of post-fresh challenges. “The transition period sets the stage for the entire lactation. Cows that successfully come through this challenging time will achieve higher production and better lactation performance,” explains Todd Birkle, DVM, fresh cow reproduction manager, Pfizer Animal Health. “It’s important for producers to put systems in place that prepare all cows for success while catching those that experience post-calving challenges.”

Producers have a variety of informational tools available to monitor both the mastitis in their herds and the quality of milk being shipped to processors. Somatic cell counts (SCC) are a measure of mastitis in a dairy herd. The SCC will increase in a quarter as a result of an infection. The increase represents white blood cells entering the quarter to fight the infection. The bulk tank somatic cell count (BTSCC) reflects the total number of infected mammary quarters in the herd that are actually being milked into the tank. The bacterial count is another primary measure of milk quality. Bacteria are present in milk as a result of milking infected mammary quarters, contamination from the environment during milking, dirty milking equipment and growth during milk storage.

The LPC test is doing a standard plate count on pasteurized milk. The mastitis pathogens are killed and what remains are organisms that keep on growing in the milk and reduce shelf life. These organisms are not from cows’ udders. They are usually spore–formers, like bacillus or pseudomonas, which live in rubber hoses and some water supplies. If a high LPC count is present (250 to 300 cfu/ml is the usual cut-off point), use the following procedures to ensure you stay below these levels. 1. Milk clean, dry, pre-dipped teats and udders. Sand bedding and muddy lots are big suppliers of non-cow bacteria. Milking wet and/or dirty teats will load up the tank with them.

Mastitis continues to be the most costly disease on dairy farms. It decreases profit as a result of decreased milk yields, treatment costs, discarded milk, premature culling and death, decreased genetic potential and decreased reproductive performance. High somatic cell count (SCC) milk also decreases cheese yield and reduces fluid milk shelf life. The best way to reduce SCC is by focusing on prevention. If your SCC is higher than desired, one way to tackle the problem is to consider forming a milk quality team. Include key employees, veterinarian, dairy plant field representative, dairy equipment personnel, extension personnel, etc. Work with them to develop a systematic game plan for reducing your SCC based on your farm’s information. Mastitis is a disease that is well understood and often an aggressive plan of attack will get it under control.

Muddy conditions resulting from wet weather constrain best management practices; animals, feed and the environment can all be negatively affected. Under these conditions, two major ailments can affect dairy cows: mastitis due to environmental bacteria and lameness. Cows with mastitis decrease production, have greater treatment costs and can eventually be culled or die. Lame cows incur higher production losses, lower fertility and greater culling rates.