Image: Brian Bulin
The BeefWatch webinar series recently addressed research and tips about cattle nutrition. Image by Brian Bulin

Weekly webinar series discusses research and tips for cattle

Farmers and ranchers who allow their cattle to feed on corn residue, the leftover corn after harvesting, need to know how long those cattle can stay in a particular field before moving the cattle to a new one and when to add supplements to their diet.

That was the topic of discussion on Tuesday night’s BeefWatch webinar series with speaker Mary Drewnoski, associate professor of animal science at the University of Nebraska. 

Beef Watch, a weekly webinar on Tuesday evenings by the University of Nebraska Beef, focuses on providing management strategies, nutrition, production and profitability for cattle. Each webinar focuses on one specific topic by different professors and researchers with time at the end for questions and answers from participants.

Even though the webinars are free and open to the public, they are focused on research in the beef and agriculture industry which may pique the curiosity of a particular audience of farmers, researchers and those in the industry.

During this webinar, Drewnoski spoke about the questions

Mary Drewnoski 582 150x150 - BeefWatch webinar helps farmers, ranchers ensure cattle growth
Mary Drewnoski presented during Tuesday nights Beef Watch webinar series. Photo:

she gets asked the most by farmers and ranchers, mainly, how does one determine the stocking rate? How does one know when to move cattle from the field? And, when should supplementation be provided to cattle?

Spring calving cows are the most common cows out on grazing corn residue with low requirements of around 11.5/lbs total digestible nutrients (TDN) and about 1.6/lbs crude protein, which means they do not need to have a highly nutritionally dense diet. In fact, corn residue is better than the requirements for mid-gestation for grazing. 

“Understanding what is available to the cattle is extremely important,” Drewnoski said. “The grain that is actually left in the field is, of course, going to be the best energy that is available.”

During late gestation, more requirements are needed in the months of December and January time period for spring calving. The important thing to remember, Drewnoski said, is that cows need to be weaned on to grain little by little otherwise complications could arise with the cattle.

One of the biggest problems farmers face when grazing their cattle in the field is that most farmers want all of the corn to end up in the combine and not in the field. 

Weather is the biggest element for farmers to watch when grazing their cattle in the field.

A lot of residue can be lost to the cattle trampling the corn residue, especially if the weather is particularly wet. 

Drewnoski said that grazing should remove about 13-15% of the residue before moving the gestating cattle. If farmers walk their field and really look hard and cannot find husks, it is time to move the cattle. Farmers should not pay attention to how much leaf or stem is in the field because the cattle should not be eating corn stock stems.

There is a way to determine how long cattle can be left on the field. Drewnoski has her own rule of thumb to determine this. For every 100 bushels of corn taken out of the field, a cow can graze for about a month.

“This is a pretty crude measure,” Drewnoski said, “but gets you in the ballpark.”

In her webinar, Drewnoski goes into much more detail about how to accurately determine grazing cattle in the field through simple equations and a farmer’s particular yield. Her webinar can be viewed on the Beef Watch webinar page.

BeefWatch will conduct additional webinars through the end of November. To join the discussion, view previous webinars or view the upcoming calendar and register, visit BeefWatch webinar series page.

Senior Journalism, Broadcasting and Advertising Student.