Fat Matters

7 Nov 2016

By Victoria G. Myers
Progressive Farmer Senior Editor

Keeping cows on a 365-day calving schedule takes more than a good bull. It requires good body condition.

Standards for scoring body condition go back years and are well-defined. "This is an easy tool to pick up, and there are detailed descriptions available," says Lisa Kriese-Anderson, Extension beef specialist at Auburn University.

Anderson says while her body condition score (BCS) of 5 may look slightly different from someone else's 5, the idea is to get in the ballpark. And it's important because the correlation between body condition and conception rate in a herd has been proven over the years. By meeting a BCS of 5 for a cow and 6 for a first-calf heifer, 90% conception rates are achievable.

A study from Purdue University notes the relationship between body condition and the average interval from calving to first heat, showing a BCS of 3 correlates to an average postpartum interval of 89 days; whereas a score of 5 averages 59 days.

SORT BY BODY CONDITION

Anderson says it's important producers remember to differentiate cows from heifers when it comes to body scoring because of different life stages.

"The cow does not need as much nutrition as a growing heifer," she explains. "At a 5, the cow will have enough reserve to have the energy to calve, start lactation and be rebred. The heifer needs to be a 6 because not only does she have to do all the same things the cow does, but she is still growing."

The beef specialist adds a heifer should be at 85% of her mature body weight when she calves, meaning she still has 15% more growth ahead of her.

A good time to check and record body conditions is at weaning, Anderson suggests. Most producers wean calves at 9 to 10 months of age. Assuming the cow or heifer was rebred, she would have about three months to get ready to have the next calf. This allows any necessary gain in body condition to be slow and planned out.

"Let's say you have three months, and you need to go from a 4 body condition to a 5. You would provide enough nutrition to increase body condition by about one-third each month," she advises.

Anderson says trying to boost body condition too quickly can upset the rumen, causing a cow to go off her feed and setting the whole process back.

The most economical approach to improving body condition requires sorting out thin cows and heifers so they can be fed separately. In some cases, the heifers and thin cows can be grouped, but Anderson cautions this may not work if older cows are pushing heifers out of the bunks. She advises watching the group at feeding a few times to be sure the system will work.

FEED VALUES COUNT

When working to improve body condition, it's important to choose the most economical supplements by year and region. Anderson says some years that may be corn, other times soy hulls or dried distillers. On protein, she prefers a natural source as opposed to urea. Crucial to this process is an analysis of hay or standing forages to be sure all nutritional requirements are met.

"Unless you test your hay, you don't know the value," Anderson stresses. "When you are trying to improve body condition, you are taking the values of all your feedstuffs and developing a ration that is about 10% above their requirement. You can't do that if you don't know what you're feeding. Hay has to be tested. On most other feedstuffs you can go on book values, but not hay, because it's such a variable commodity."

AVOID FLESHY COWS

It's possible to have too much of a good thing. Anderson says fat cows or heifers are just as bad as those that are too thin. In a heifer, too much fat can even affect lifelong milk production.

"For me, I would not want a cow to be much more than a BCS of 7, and I'd apply that to heifers, as well," she says. "The fatter heifers get the more fat goes into the udder, and it reduces productive space for milk production permanently. They can get so fat it's hard to rebreed them, so you want to keep the herd at those optimum 5 or 6 body condition levels."

For More Information:

-- University of Nebraska's guide "Body Condition Scoring Beef Cows" is available at extensionpublications.unl.edu/assets/pdf/ec281.pdf.

-- A body condition score mobile app can be downloaded from Google Play or the Apple store. Search for "NUBeef-BCS".

(VM/AG)