HUNTIN' DAYLIGHT -- NEW LIMIT-FED, HIGH-ENERGY STRATEGY FOR CALVES

by: Wes Ishmael

Talk with someone about starting calves on a high-energy ration and they'll likely discount everything you have to say afterward. The reason is simple. High-energy diets fed to calves are often associated with increased morbidity, stemming from acidosis and other metabolic disorders.

That's still true when corn (fermentable carbohydrates, starch primarily) is the main energy source and cattle are fed ad libitum. However, replace much of the ration's energy from fermentable carbohydrates with that from fermentable fiber and there can be lots of benefits and no added health risk, according to several research trials conducted by Kansas State University (KSU) over the past couple of years.

Think here of substituting corn with the fermentable fiber of wet corn gluten feed (WCGF) or the fermentable fiber and fat in wet distillers grains with solubles (WDGS). More specifically, consider a diet providing 60 Mega calories (Mcals) of Net Energy for Gain (NEG) per 100 lbs. of dry matter, fed at 2.0-2.5 percent of body weight.

“Results from these trials indicate high-energy diets based on corn by-products can be fed to newly received stocker cattle without negative effects on overall health,” say Dale Blasi, KSU Extension beef stocker specialist and Tyler Spore, who is now a doctoral student at the University of Nebraska. Spore led four successive, non-sponsored research feeding trials at KSU's Beef Stocker Unit (BSU) in 2016.

“From a ruminal health perspective, minimizing the level of starch in the diet will avoid the potential occurrence of subacute ruminal acidosis that can negatively affect consistent feed intake and potentially jeopardize cattle health,” they say.

The trials included 1,444 head of calves received at the KSU Beef Stocker Unit in Manhattan, Kansas from Montana, Florida, Texas, New Mexico and Tennessee. On the day of arrival, all calves received long stem prairie hay. The limit-fed diet was introduced to the calves on the following day at a feeding rate of 1.0 percent to 1.5 percent Dry Matter (DM) on a body weight basis.

For reference, the 60 Mcals ration used on a dry matter basis was primarily: 40.00 percent WCGF (Sweet Bran®; Cargill Corn Milling), 38.82 percent dry-rolled corn, 8.18 percent low energy supplement (10 percent CP), 6.50 percent alfalfa hay and 6.50 percent prairie hay.

“The desired maximum amount of dry matter intake allowed (2.0-2.2 percent of body weight) was attained within one to two weeks, as dictated by cattle appetite, which can be curbed by limit-feeding,” Blasi explains. “Results from these trials indicate it is important not to over-fill cattle too quickly and to keep them hungry initially.”

When limit-fed, the diets with energy coming from fermentable fiber yielded several obvious benefits, including increased feed efficiency and the opportunity to alter intake in order to select gain, using the same diet.

Depending on producer location and commodity markets, Blasi points out another advantage is being able to use the by-products interchangeably.

Limit-feeding Benefits

Most producers familiar with limit feeding got acquainted via supplemental feeding to navigate drought.

“Limit feeding or program feeding refers to the practice of limiting calves to two-thirds to three-quarters of the dry matter that they can normally consume,” Blasi explains. “This feeding strategy varies greatly from traditional management where calves generally have free-choice access to forage. Traditionally, limit-fed diets have consisted of 80-85 percent whole-shelled corn and the remaining balance as a protein supplement. The total amount of the ration delivered is increased every two weeks or so to account for increased body weight gain based upon the desired level of gain.”

Limit-feeding is not for everyone. It requires tighter management, for one thing, and the ability to feed calves in a pen.

“For example, adequate bunk space and maintaining a regular feeding schedule are necessary,” Blasi and Spore explain. “Cattle need to be fed the same amount at the same time every day in a pen situation where all calves have an equal chance to get to the bunk. Moreover, the producer must recalculate and adjust the ration dry matter allowed every couple of weeks to account for cattle growth. Therefore, it is important to have accurate cattle weights before initiation of the feeding period (and during if possible) to ensure proper amounts of feed are being delivered.”

In return, along with more efficient gain, limit-feeding reduces feed wastage and increases the odds that all of the calves are eating rather than selecting parts of the ration.

“With limit feeding, every bite they get is high calorie and consistent. When you limit feed and have a slick bunk, there's no doubt that what you're feeding is going into the cattle, including minerals and feed additives,” Blasi says. He adds that feeding a single diet minimizes the potential for error that comes with manipulating transition diets.

Increased digestibility and efficiency from intake restriction can also mean less total manure production.

Then, there's the health monitoring aspect.

“Limit-feeding makes for hungry animals that are more than eager to approach the bunk at feeding,” say Blasi and Spore. “This concept is beneficial in regard to monitoring cattle health because when an animal is not at the bunk to meet the feed wagon it is likely due to a health issue and earlier detection is paramount when dealing with newly-weaned, stressed calves.”







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