Missed Diagnosis

And that doesn't count the cattle that were sick and never pulled. Several research trials from the 1990s indicate clinical signs of disease can go undetected in the feedyard.

In a trial at the Meat Animal Research Center in Clay Center, NE, 68% of steers never treated for sickness showed lung lesions, indicating they had a respiratory infection sometime in their life. Meanwhile, an Oklahoma State University (OSU) trial found 37% of cattle never diagnosed as sick had lung lesions. While some of the scarring may have been from a viral infection, from a respiratory disease incident before the cattle arrived at the feedyard or from a subclinical infection, a portion of it likely is due to being missed by the pen riders.

Radar for the Feedyard

What if you had an early warning system to tell you if a calf might get sick? One could be on the way that could cost-effectively serve as an electronic pen rider, constantly on the lookout for early signs of sickness.

It's a temperature-sensing bolus that stays in the rumen throughout an animal's life.

“There have been rumen-based temperature boluses since the mid '90s,” says Steve Trost, founder of Strategic Solutions International of Stillwater, OK, and inventor of the TrueTag health monitoring system. “The problem with previous approaches was their relatively high cost, which relegated them primarily to use in research.”

Trost's system aims to correct that problem by being a cost-effective way to monitor an animal's internal temperature. When the bolus senses an animal has exceeded a temperature threshold, it sends a signal. Depending on the system, that signal is detected by an ear tag that flashes a light, alerting pen riders to a potential health problem in the making. More advanced systems relay the data to a computer in the office, where cattle health can be monitored constantly.

Trost says early detection of a rise in body temperature can be important, since cattle will start running a temperature a day or two before clinical signs of a respiratory infection begin to show.

While the system isn't yet available commercially, Trost is working with an advisory panel of ranchers, cattle feeders and veterinarians to develop the system.

“Some of the initial feedback we got from the industry strongly validated the importance of temperature monitoring without having to put the animals through a chute,” Trost says. The stress of handling the animal can increase its temperature, and the ability of the person taking an animal's temperature manually can affect the reading, as well.

Trost's goal is to hit a $10/animal entry point for the basic technology — the bolus and ear tag. However, because the system is completely scaleable, it can be made to fit any production system, from cow-calf to stocker, and through the feedyard.

Will it pay? Perhaps. The Noble Foundation of Ardmore, OK, reported that the importance of having healthy calves and early treatment of calves with bovine respiratory disease is amply demonstrated. Its experience with stocker calves showed that healthy calves gained 0.98 lbs. more/day than untreated sick calves. In addition, treated calves gained 0.52 lbs. more/day than untreated sick calves.

At 50¢/lb. cost of gain, the healthy calves produced $13.72 more/head during a 28-day period than untreated sick calves; treated calves produced $7.28/head more than untreated calves. That difference would increase as the calves remained on pasture longer.

It's even more evident in the feedyard. A six-year summary of Texas Ranch to Rail data showed healthy steers had a total cost of gain of $55.89 and returned $69.98/head on average. Sick steers, on the other hand, had a $65.73 total cost of gain and lost an average of $28.45/head.

In addition, Trost says cattle feeders on his advisory panel indicate the system has value not only in telling pen riders which calves to pull, but also in checking and training pen riders on pulling cattle correctly. That's important, he says, because the OSU research showed that 52% of the cattle pulled and treated didn't show any lung lesions. Some of that may be because the cattle fully recovered with treatment; some is likely due to pen riders misdiagnosing and over-pulling cattle.

Bottom line is this: Once they get sick, they never catch up. And, adding injury to financial insult, the cost of that sickness extends far beyond the medicine room.

Table 1. Feedlot performance and income for steers that remained healthy vs. steers that were treated for sickness, New Mexico Ranch to Rail program

	Healthy	Treated	Difference
Number of steers	636	177	—
Initial weight, lbs.	608	602	6
ADG, lbs./day	3.2	2.9	0.3
Carcass weight, lbs.	778	766	12
Medicine cost, $/head	$0	$36	$36
Carcass price, $/cwt.	$114	$110	$4
Gross income, $/head	$856	$797	$59
Source: Waggoner et al; 2007