By Sharla Ishmael

Considering that nutrition is perhaps the backbone of any profitable cattle enterprise, what would it be worth to you to know (on a monthly basis if you desire), whether your broodcows are getting the right balance of protein and energy to reach peak lactation and breed back quickly?

Or to know you could squeeze more money out of those stocker calves if you sell them now because the forage they are grazing no longer supports cost-effective gain?

Or to know one of your pastures would be better suited to grow out your replacement heifers than another?

What about simply knowing when – or if – you need to start winter feeding and when you can stop putting out those round bales and range cubes?

These are some of the questions that can be answered, or at least better understood, through a nutritional monitoring program developed by Dr. Jerry Stuth, Kelleher Professor at Texas A&M University’s rangeland ecology and management department, and run by the Grazingland Animal Nutrition (GAN) Lab in College Station, Texas.

The program – which a survey of participating producers indicates generated an extra $25 to $38 per cow – has two elements.

First, producers collect manure samples on a group of cattle they want to monitor. The composite sample is sent to the GAN Lab and analyzed using near infrared reflectance spectroscopy (NIRS), which determines the diet quality of the animals represented in the fecal sample.

Second, the numbers generated from the NIRS Lab work can then be plugged into NutBal, a software program that does all the complicated equations to determine if the animals’ needs are being met; to project daily gain/loss; and to determine most cost-effective feeding option.

If you’re feeding a 4-H calf out of a bucket, you know what and how much that animal is eating. But, dealing with cows dependant on grazing for all of their groceries makes nutrition a different game.

Before this program was developed (jointly by A&M’s Ranching Systems Group and the Natural Resources Conservation Service (NRCS)), "About the only way to really determine what a grazing animal was getting," explains Doug Tolleson, GAN Lab director, "was to take an animal that had surgery to put a plug into their esophagus so you could turn the animal out, collect what he grazed in a bag and then do an analysis to tell what the animal was eating."

The analytical portion of the program, NIRS, provides a snapshot of the chemical makeup of the manure sample.

How? Tolleson explains, "It works a lot like our eye works with visible light in that chemical bonds vibrate at certain frequencies, which correspond to frequencies in the near infrared band.

"So, a bond vibrating at a frequency of near infrared light will absorb that frequency and reflect the others – like we see blue because certain light is absorbed and the blue light is reflected."

Once the chemistry of the manure is identified, then the GAN Lab can back-calculate the quality of the animals’ diet relative to the amount of protein and digestible energy in their diet.

The GAN Lab can also calculate the amount of fecal nitrogen and phosphorous being returned to the ground. This analysis can be used as a monitoring method for operations under confined animal feeding regulations.

Tolleson says some producers leave it at that. All they want to know is how much protein their forage base is providing and they don’t follow up with a NutBal analysis.

However, the software program can take the NIRS data and turn it into information which can be used to make all kinds of better management decisions – a real decision support system.

"The backbone of this NutBal program is the NRC (National Research Council) nutritional requirements," Tolleson explains. "There are manuals from committees of experts who look at all the research and say, ‘Here’s how to determine how much protein an animal needs and here’s how much energy, vitamins, minerals, etc.’

"You can look (in the manuals) and find equations that tell you if you’ve got an animal this size or this breed in these conditions, this is how to figure their nutritional needs," he says. "It also has tables telling you corn has this much protein, wheat has this much, all the different feedstuffs available to formulate a ration."

All of these equations and tables have been programmed into NutBal, so a computer can do the analysis.

But, the rancher must provide information on the cows when a fecal sample is submitted. One of the basic pieces of information is the breed of cattle being monitored. Breed types differ in metabolism and energy requirements due to higher proportions of soft tissues, such as the liver and the digestive tract, which increase net metabolism.

For example, dual-purpose breeds, like Simmental, are adjusted up for energy while Bos indicus breeds are adjusted down.

Other key animal factors influencing nutritional needs are hair length; hide thickness; peak milk yield; age; lactation; sex; body condition score; and parasite load.

Environmental conditions must also be described to get a true assessment of the herd’s needs. Report vegetation type; slope of the pasture; water distribution; current temperatures; high and low temperatures for the past 30 days; average humidity; three- to five-day average windspeed; sunlight exposure; and an estimate of available forage standing crop.

Of course, if you are feeding any kind of supplemental feed, relay that information to the GAN Lab as well, with feed tags if possible.

So, you gather the fecal sample, send in the form that describes your animals and their environment … then what?

One of the unique aspects of the GAN Lab, says Tolleson, is their quick turnaround. If a producer sends in a sample on Monday, he or she can have their full report by Friday. "That’s about as close to real-time nutritional monitoring as you can get," he says.

The GAN Lab report is like the balance sheet used by accountants. But instead of comparing a ratio of assets to liabilities, NutBal compares protein and energy intake (as predicted by NIRS) to the requirements needed by the class of animals and environmental conditions which were described.

If the requirements are greater than the intake, it will calculate how to fix the imbalance. You’ll also receive a brief summary explanation of the various numbers. (See a sample report online at http://cnrit.tamu.edu/ganlab.)

Tolleson gives an example of the information a rancher might submit. "We put in (the herd consists of) lactating cows of the Angus breed, that weigh 1,100 pounds in a Body Condition Score 5. Temperature is 40 degrees for the high and 25 degrees for low." These are the factors used to calculate that animal’s nutritional needs.

"The software will generate a report that says this animal should be gaining a pound a day, milking to potential or maybe it’s losing half a pound a day and it’s deficient in protein. We could feed a pound of cottonseed cake to get the animal back over into a positive nutritional state."

The program also allows the participant to run what-if scenarios. The user can plug in multiple animal classes, or available feedstuff combinations or project gain based on certain criteria. The more you know about nutrition, the more you can fine-tune the analysis – assuming you’ve attended a training seminar to learn the software.

If your nutrition knowledge is limited or you don’t have the time or interest to learn the software, then there are several ways to access these services.

"The majority of the people we work with come through the NRCS," explains Tolleson. "Their personnel will go out to ranchers in their area that they work with on grazing management. If they feel that taking a fecal sample and getting the diet quality of their animals will help them do a better job of managing their grazing resources, they can participate.

"A producer who wants to work with us directly can go on our web page or give us a call. They can work with us just like they might work with the vet diagnostic lab or the way they send in hay samples to the agronomy department. They can also work through Extension agents, livestock specialists and there are some veterinarians who are working as a client representative helping them design nutritional programs."

It costs $25 to have a fecal sample analyzed and another $25 if you want the results run through NutBal. Tolleson says it also costs about $3 to mail the sample by two-day priority mail. So, that’s a one-time expense of about $53. However, a one-time snapshot probably is a waste of money.

"It depends on your goals," Tolleson explains. "In general, you should sample a particular group of animals once a month if you really want to establish some baseline information. You should really do that over two or three years. After that, you can probably identify three to five key times of the year when you need to sample.

"If you’re doing intensive rotational grazing, once a month is probably not enough. It all depends on your management and your goals."

The GAN Lab will run fecal samples and the NutBal analysis one at a time or through their package deals which include training in NutBal software and/or volume pricing on samples.

A two-day NutBal training seminar costs $250, and the participant takes the software home free. It cannot be purchased any other way.

They are also developing a web-based option. Participants go to a password-protected site, log in their own sample, fill out the NutBal information and receive an email notice when the sample is reported and the automated case has been run. The automated sample and NutBal cost $35.

The GAN Lab processes up to 10,000 samples a year, of which approximately 80 percent are cattle. They also have developed equations for nutritional monitoring of sheep, goats and wildlife species such as white-tailed deer, elk and bison.

"We’re hoping to get more into the wildlife side because we’re doing some other studies where we can tell differences in fecal samples that come from male animals versus females, young versus old. It could become a census technique," says Tolleson.

"We have an East African student who’s working on developing equations for donkeys. The donkey is the SUV of a lot of the world; they are the truck and the tractor and the schoolbus. But there’s not a lot of nutritional information out there about donkeys," he adds.

"A lot of what we do is everyday ranching type stuff, some of it is more off the wall. But we might find some method with these exotics, that we would never have thought of, that works for livestock as well."

For example, some of their research indicates it may be possible to use fecal sampling to determine pregnancy and internal and external parasite loads.

There seems to be no limit on the application of this technology, even among everyday cattle producers. NutBal can be a real educational tool for producers who don’t know much about nutrition. It can be a good support tool for folks who do know a lot about nutrition, but haven’t been able to quantify some of the things they do with grazing animals.

Producers are using NutBal for everything from deciding when, or if, to start winter feeding to using diet quality information to make decisions on what variety of grass seed to plant.

"On large landscape areas, because of the species composition, soil type, water runoff, all the things that go into it, you may have a pasture that has a better forage base in it than another and can provide higher quality grass at key time periods," Tolleson adds. "So, you might determine you’re going to grow your heifers out in the better pasture or put your lactating cows out during that time when you know the grass is the highest quality to meet their lactation needs and get those cows bred back.

"Another (way to use it) would be in a rotational grazing system," he says. "I can go out and measure how much grass is out there when I turn cattle in and then graze it to a certain stubble height and move out.

"But you can add to the quantity measurement a quality measurement. You may get to a point where there is some grass left to graze, but it may not be the quality needed to meet the goal for the type of animals you have."

"Exactly what we do is unique," Tolleson says. "There have been independent labs developed in Australia. Then we have set up, in cooperation with other countries, labs in Argentina and four or five East African countries.

"As far as the producer in Texas who wants to go out and get similar type of information … they can go out into their pasture, and if they feel like they can simulate what their animals are eating pretty well, can clip a forage sample and send it to any reputable forage analysis lab and get similar type of information. Those are good, workable systems, also.

"The drawback is having enough knowledge and time to know that you’re simulating what that grazing animal is choosing," he explains. "That’s probably not that big of a deal on a Bermuda grass or rye grass pasture, where you can look at the height that’s being grazed and probably get pretty close.

"But if you think about trying to do that in the Edwards Plateau or South Texas where they have a multitude of plants coming and going at different times of the year, and how much leaf versus stem, brush versus grass versus weeds, that gets pretty difficult to do."

Or you can have the NIRS/NutBal analysis done and know for sure.

For more information on NIRS/NutBal and the nutritional monitoring of grazing animals, contact the Grazingland Animal Nutrition Lab at 979-845-5838 or check their website at http://cnrit.tamu.edu/ganlab.