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January 19, 2001

Cattle-working basics
bear repeating

Proper storage, techniques ensure vaccine efficacy, reduce risk of infection...

By Lana Robinson
Field Editor

Proper methods of vaccination, branding, and castration are frequently among the basics covered during cattle working demonstrations at the Texas A&M University Agricultural Extension and Research Center in Overton. Dr. Todd R. Thrift, Extension livestock specialist, presents a variety of commonly-used products and practices and offers comments on his preferences.

First, Thrift advises producers to purchase products from a reputable dealer, noting that the refrigeration of the vaccine from the point of manufacturing must be maintained to ensure 100 percent efficacy.

"Transfer vaccines in coolers from the dealer until the product can be refrigerated at home, and/or until it is mixed and administered into the calf," says Thrift. "You can use cool packs to transport vaccines."

Avoid liquid sterilants

Thrift cautions against the use of liquid sterilants for disinfecting syringes, advising instead that components be placed in boiling water before use.

"No alcohol, bleach, soap, betadine, etc. All of these will inactivate modified live virus (MLV) vaccines upon contact and cause damage to killed (K) products," he says.

The livestock specialist also warns against lubricating syringes with petroleum jelly, which he says can also inactivate MLV products. He also urges protection of the vaccine and syringes from sunlight and heat, which can also weaken the vaccine.

"Mix only enough vaccine to last 30 minutes or less at a time," says Thrift. "You've got to use MLV products when they're mixed. You can't refrigerate them for later use. Killed products should not be kept after they have been drawn from either, unless a sterile needle was used each time the vaccine was removed from the bottle, which you ought to be doing."

Thrift recommends keeping the "working bottle" of vaccine in a cooler with the syringes along with cool packs. Any unused product should be kept in another cooler away from the working area, he says.

Label syringes

"If you're using more than one product, label syringes so mistakes are not made in drawing vaccines, he adds.

Inspecting the working parts of the syringe and calibrating before, during, and after use is also recommended. Some syringes can easily be changed to avoid under- or over-dosing of the product.

"Make sure the proper dosage is administered," he says, noting that many products are now administered in 2cc doses instead of the old standard of 5cc. "Calibration of syringes is critical to properly administer these low dose products."

Thrift emphasizes the importance of injecting animals at the proper site to avoid lesions in choice cuts of meat.

"When possible, vaccinate in front of the shoulder. Intramuscular injections should be given 2-3 inches below the top of the neck and 4-6 inches in front of the shoulder blade. Subcutaneous injections should be given in the neck region or behind the foreleg, in the elbow pocket," he says.

Finally, he says to booster all vaccines and bacterins per label instructions, adding that a booster is normally required two to four weeks after vaccination.

Branding techniques

Due to the unreliability of eartags, Thrift recommends a permanent brand, notching ears, or a mark of some kind on cattle (which should be registered) to show ownership.

"If you firebrand, place it up close to the tail. You don't want a hole in a cowhide that otherwise could be used for leather seats in a Cadillac," he says. "And never brand wet cattle."

Thrift notes that care must be given to avoid damage with other forms of branding, including freeze-branding. When super-cold or chilled branding irons are applied to the hide of the animal, the pigment-producing cells are destroyed or altered. When the hair grows back, it is white. The method is not foolproof, and those using it should be aware that the results may be variable.

The major advantages claimed by freeze-brand proponents are 1) the brand is more legible throughout most of the year than a hot-iron brand; and 2) freeze branding causes less damage to the hide than a hot brand.

When to castrate?

Bull calves are generally discounted at local auction barns, and the discount that bulls receive is directly related to weight. A number of studies suggest that calves purchased as steers gain faster and require fewer treatments the first 30 days following arrival at a feedlot than calves purchased as bulls and castrated upon arrival. Moreover, the steers continue to gain at a faster rate than their newly-cut counterparts.

"You may as well castrate your bull calves early on because sooner or later, someone is going to cut him," Thrift tells producers.

He says the best time to castrate is between birth and four weeks of age, when there is less stress on the bull calf. Also, in a spring calving herd, the fly population is from small to nonexistent at the time of calving. This results in a reduced chance of wound infestations by parasites and reduces excessive bleeding.

Thrift favors knife cutting bulls.

"You don't want your knife dull, but you don't want it razor sharp either, or you'll have a lot of bleeding," he explains.

The Extension livestock specialist recommends twisting the scrotum and cutting about halfway down, then removing both testicles with a pulling motion, severing the cord.

"You can use the castrating bands on young calves (a band which is stretched and slid over the scrotal sack with a tool), but make sure you get both testicles, otherwise, he's still a bull," Thrift advises. "But it's been my experience that you can cut two or three with a knife by the time you can band one."

If bands are used, the ring must be tightened enough to cut off the blood supply to the scrotum. If the procedure is completed properly, the scrotum, with the Ring and Clip intact, will drop off within 20 to 40 days. At this stage of the process the scrotum should be healed and the possibility of infection minimal.

As with any procedure that violates the animal's protective hide, there is a possibility of infection. Many ranchers use pine tar as a disinfectant, and it can be applied at the same time the castrating tool is used.

"If you go this route, I'd recommend giving them a Tetanus shot," Thrift adds.

Castrating prior to weaning would be the next best option, but the younger the bull, the less traumatic the event and usually less bleeding, he said. Another reason to castrate early is that an eight-month-old nursing bull calf may have the ability to breed young females.

Another option, according to Thrift also, is a castrating tool which utilizes a twisting action, effectively closing the severed cord. He says it may be used on any age bull, but is an especially effective method to use on older heavier bulls (500 to 900 lbs.) where it is important to minimize the risk of blood loss, swelling and infection.