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Kevin Spurlin Extension Agent, Grayson County, spurlink@vt.edu

I am blessed to have the perspective of both nutritionist and dairyman when it comes to feeding dairy cows. I have formulated rations for other farms, and been up in the wee hours of the morning mixing and feeding the TMR on the home farm. Watching cow behavior is one skill I have developed that has made me a more effective nutritionist and dairyman. Have you ever watched cows eat? It may be about as entertaining as watching grass grow, but what you may learn could be invaluable.

Dr. Trevor DeVries of the University of Guelph has researched cow feeding behavior extensively. He states that cows on pasture will spend about 8 to 9 hours grazing during the day. During these grazing events, cows are highly selective in what they consume, yet also highly consistent in what they consume. A cow’s ability to be consistent results in more stable digestion throughout the day.

In comparison, TMR-fed cows often in confinement housing such as pack or freestall barns spend about half as much time eating (3 to 5 hours/day) as compared to grazing herds. They also eat about 1.5 to 2 times as much total dry matter per day. In essence, cows in confinement eat larger meals faster, and less frequently. The tendency of TMR-fed cows  toward “slug feeding” necessitates a close look at feed bunk management and diet formulation to avoid problems caused by this type of feeding behavior. To do this, watch cows eat!

First, pay attention to when cows eat. Dr. DeVries notes that the delivery of new feed is the primary driver of when cows eat. Milking is often a secondary driver. Combining milking and feeding events at the same time is very stimulating to cow feeding behavior. By staggering feeding times and milking times, a farmer can spread out the feeding pattern leading to more stable intake and a more stable rumen environment. If this is done, ensure that the feed available at milking is high quality and plentiful or the benefit of a staggered feeding is negated. Pushing up feed, while important, is less of a stimulating factor than we may have previously thought. If some cows are not eating at these important times such as milking or feed delivery, ask “why not?” Is feed bunk space limiting access to some cows? If a few cows are not eating at those critical times, are they sick or in heat?

Second, are cows sorting excessively? Cows have a tendency to be selective. Cows that push their noses into a large pile of feed and start making a circle are pushing fibrous feeds to the edge to gain access to delectable morsels at the bottom. Smaller portion sizes at each feeding will limit this activity somewhat. Excessive sorting impairs digestion of the cow doing it, but that behavior also changes the diet consumed by the next cows into that spot. In pens of cows with severe cases of sorting behavior, two cow-side symptoms include variable manure consistency and variable body condition at the same stage of lactation indicating that all cows in the pen are not consuming the same diet.

Dr. DeVries advises that proper nutritional management allows cows to eat a ration balanced to meet their requirements, and do so in a manner that is good for the cow. Two critical steps to achieve those goals is 1) provide access to the formulated diet throughout the day by taking advantage of cow feeding triggers, and 2) minimize competition at the feed bunk through proper bunk design and stocking density. Observe and manage cow feeding behavior to ensure the diet properly formulated, mixed and delivered is actually the same one consumed by the cow.


Virginia Cooperative Extension materials are available for public use, reprint, or citation without further permission, provided the use includes credit to the author and to Virginia Cooperative Extension, Virginia Tech, and Virginia State University.

Issued in furtherance of Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State University, and the U.S. Department of Agriculture cooperating. Edwin J. Jones, Director, Virginia Cooperative Extension, Virginia Tech, Blacksburg; M. Ray McKinnie, Administrator, 1890 Extension Program, Virginia State University, Petersburg.

Publication Date

May 2, 2017