Cattle Nutrition Simple Matter
Of Getting Complex Mix Right

By Colleen Schreiber

UVALDE — Producers attending the recent Cattleman’s Gathering In The Southwest here heard from a variety of speakers relating to nutrition and health.

Amarillo-based Extension livestock specialist Dr. Ted McCollum focused on supplementation needs of cattle on native pasture.

McCollum cautioned that both energy and protein must be considered when supplementing cattle, and he stressed the importance of the rumen in properly utilizing those nutrients.

"About 70 percent of the energy utilized by cattle is generated by volatile fatty acids that come off the fermentation process in the rumen," McCollum said, "while the majority of the protein that is digested in the small intestines is generated from microbial protein in the rumen.

"Therefore, if things aren’t functioning adequately in the rumen, these animals will automatically be shorted on energy and protein."

With grazing cattle, McCollum noted, energy intake is going to be the primary limiting factor in overall performance. That said, he added, for many cattle on forage, the protein content of the diet actually limits the amount of energy they consume in the form of forage, as well as the amount of energy that is yielded from digestion of that forage.

"So even though energy is limiting performance, the primary nutrient that you should be concerned with is protein," he explained.

As a rough rule of thumb, McCollum told listeners, forage intake will be suppressed when forage contains less than seven to eight percent crude protein. Feeding supplemental protein in these situations, he noted, will thus improve intake and digestion, in turn addressing the ultimate goal of increasing energy intake.

What feed is best, then, and in what situation does it work best? McCollum told listeners they can expect anywhere from a 30 to 60 percent increase in forage intake when using 35 to 41 percent protein supplements. He noted, however, that protein supplements aren’t likely to be as effective if there is a grass deficiency.

Animal nutritionists talk about two different kinds of protein in their discussions of supplements. Bypass protein is a form that bypasses the rumen more or less intact and is instead broken down in the small intestines.

All proteins with the exception of urea contain both bypass and rumen-degradable components, McCollum told the group. Soybean meal, for instance, has 70 percent rumen and 30 percent bypass protein, while corn gluten meal is about 60 percent bypass and 40 percent rumen-degradable.

"If our objective is to supply protein into the rumen so that microbes can digest the forage more thoroughly, we need protein broken down in the rumen," McCollum stressed. "The types of feed put in these supplements will make a difference, and in most range and pasture situations we need rumen-degradable protein," he reiterated.

Ideally, stockmen should select as dense a protein supplement as possible, and feed it at appropriate levels.

"If a cow has a two-tenths to four-tenths of a pound per day protein deficiency, you’re not going to take care of her problems with a supplement that’s only consumed at a half to three-quarters of a pound a day, unless it’s got a lot of protein in it," McCollum noted.

He classified feeds with less than 20 percent protein as energy supplements. Those kinds of supplements, he told listeners, if fed at the "threshold" level of three pounds per head per day for a 1000 pound cow, actually decrease a cow’s forage intake by a half-pound to a pound for every pound of supplement fed above the threshold.

Finally, when pricing supplements, McCollum advised his listeners to price them according to the nutrients that are needed.

"That cow isn’t deficient three sacks of feed," he stressed, "she’s deficient two-tenths of a pound of protein, so we need to price the supplements based on the nutrients we need, and not how much the sack or ton costs."

Participants attending the seminar also heard from Andy Cole, with USDA’s Agricultural Research Station at Bushland. His topic dealt with proper care of stressed feeder calves.

"Working with stressed feeder calves," he told the crowd, "involves a little bit of science, a certain bit of art, and a lot of luck. There’s no one perfect system that will work for everyone."

The primary problem when receiving feeder calves in a stocker or finishing program is bovine respiratory disease, shipping fever in layman’s terms. The condition, Cole said, is caused by a combination of stress, viral infections and bacterial infections. It is estimated to cost the beef industry from $600 million to $1 billion a year.

Auction barns, because of the consolidation of cattle in one area and often poor care, are prime breeding places for the disease. Many auction barn cattle, particularly those in the Southeast, Cole said, receive no feed or water during their stay. Then, when the order buyer gets the animal, he feeds him the cheapest hay he can find. "Oftentimes, these animals have essentially no nutrition for a period of three to six days," Cole said. "Research has shown that when cattle are taken care of at auction facilities, there is a $23 per head advantage as to how they perform at the feedlot compared to calves that had little to no care while at auction or an order buyer’s facilities.

"You can feed a ration for about 25 cents a head a day," he pointed out, "so for about 75 cents for three days, you get a return of $23 per head. This is something we can encourage or demand that will help us greatly with health concerns."

He encouraged producers to make sure their calves are at least provided with clean water when they arrive at the barn and to limit sorting and resorting as much as possible.

For those buying "put-together" cattle, Cole pointed out the difference in value between steers and bulls in terms of sickness.

"If an animal walks off the truck intact, his chances of getting sick or dying are two times greater than if that animal walks off the truck as a steer," Cole said. "So when you buy bulls, be sure to discount them, because they’re worth a lot less in terms of health compared to a steer."

Upon arrival at any destination, whether an auction, feedyard, or stocker facility, Cole noted the importance of keeping stress at a minimum when unloading and sorting calves.

"The major stress is not the truck ride," Cole told listeners, "It’s getting them on and off the truck."

Cole recommended doing a stress management checklist when calves first arrive at their final destination.

"First, know where those cattle came from," he said. "It makes a difference if they came straight off a ranch or if they came from an auction facility. Find out how long they were in transit, and have a plan for when they arrive. Have in mind the kind of nutrition program and processing program that will be used, as well as an action plan for sickness."

Cole said he believes it’s a good practice to let the calves rest for at least 12 hours before processing them.

The major problem when the calves walk off the trucks is that they won’t eat. Research shows that for the first seven days their intake is about .5 to 1.5 percent of their body weight.

"What we’re looking for is something in the 2.5 to three percent range," Cole told listeners. "By the second week we might get it up to 2.5 percent, but normally it’s three or four weeks before the animal is eating at the appropriate levels."

Therefore, the first nutrient deficiency in stressed feeder calves is energy.

"You have to increase the energy levels as much as possible, but realizing that he’s not going to eat, make sure the animal gets the other nutrient requirements for protein, minerals and vitamins, and remember that you have to do it with less feed than normal," Cole told listeners.

In the feedlot, as energy intake levels increase, the number of sick calves generally increases as well.

"We think it’s because of acidosis, but we can’t distinguish between acidosis and respiratory disease in these calves."

Cole recommended feeding a 16 percent concentrate diet and free choice hay for the first three days after calves arrive at the feedlot.

For a stocker program, he recommended feeding good quality hay running in the seven to eight percent protein range and two pounds of 40 percent protein cubes each day. "For some reason, cattle tend to prefer soybean meal rather than cottonseed meal, though cottonseed is a lot cheaper," Cole said. "For calves that weigh 400 to 500 pounds, you’re looking at a diet requirement of 13 to 14 percent protein, or one to one and a half pounds of protein every day."

He also recommended a receiving diet that contains about one to 1.2 percent potassium levels, but added that feeding hay and protein cubes in proper amounts generally provides for sufficient amounts of potassium as well. Trace minerals, also important, need to be provided in proper amounts.

If expecting a morbidity rate higher than 40 percent, Cole suggested putting a coccidiostat in the ration. If less than 20 percent, he recommended using antibiotics. His reasoning for the distinction is that for antibiotics to work, the animal has to eat them, and if he is sick the chance of him eating properly is limited.

He also recommended mass medicating feedlot arrivals if the stress management checklist suggests the likelihood of pulling more than 35 percent of the cattle. In a stocker program, where it might be more difficult to work animals later, he suggested mass medicating if morbidity rates in the 20 percent range are anticipated.

Finally, he recommended following proper vaccination instructions to avoid residue and blemish problems. He encouraged producers to use subcutaneous injections whenever possible, and certainly when prescribed.