It's now possible to immunize cattle against maleness, researchers at the University of California-Davis (UC-Davis) say. They use hormone-blocking injections as an alternative to castration.

"The process should be less stressful for cattle and producers," says Chris Huxsoll, one of the researchers on the project. "For the producer, the process is quicker and easier. For the animal, the process is less painful and doesn't produce an open wound," he says.

Huxsoll explains that a series of hormones are produced by cattle, each triggering the next, that lead to growth of the testicles and production of testosterone. Testosterone production triggers the aggression, sexual activity and tough meat that are common in bulls.

Huxsoll and UC-Davis animal scientist Tom Adams developed an immunization that prompts cattle to produce antibodies to one of the hormones, interrupting the entire process.

Studies of the carcasses from immunized steers showed no difference in meat quantity and quality to that from physically castrated steers. UC-Davis animal behavior expert Ed Price studied aggressive behavior among the test cattle and compared the behavior of vaccinated males to bulls and steers. Aggressive behavior of vaccinated bulls was equal to that of steers and significantly lower than that of normal bulls.

Researchers have been looking at this method since the early 1980s. "We were able to do the job with two shots; one at weaning and another at entry into the feedlot," Huxsoll says. He believes the key to their success is a carrier protein in their vaccine that's more effective than those used earlier. Now, the researcher adds, "we need to keep the cost of the immunization low so that it's not only easier but also cost effective."

For more information contact Chris Huxsoll, University of California-Davis, at 916/752-2554.

Ponderosa pine needle ingestion can increase blood amino acid levels in beef cattle, and this may help explain why cattle eat pine needles, even though they can cause abortions in late gestation. That's according to Scott Kronberg, animal scientist at South Dakota State University.

Kronberg says pine needles contain high levels of tannins, which can increase amino acid absorption in ruminants. The cattle may eat the pine needles because they obtain positive feedback from the effect the tannins have on increasing ruminal escape protein. The improved amino acid levels also show the potential to improve the status of nitrogen and protein in the animal's blood.

Kronberg fed four yearling steers an identical diet of soybean meal and grass hay, with two of them receiving pine needles, as well. The data indicates that certain essential amino acid levels were increased by ingestion of pine needles.

Kronberg adds that a number of things may contribute to the motive behind the consumption of pine needles by cattle. For example, if an animal ingests high levels of crude protein (including urea), they may eat the tannins to reduce excessive and toxic levels of the ammonia in the blood. "They may eat them when they are hungry and there is little else to eat, and perhaps they eat them for something different to ingest," he says.

For more information contact Scott Kronberg, South Dakota State University, at 605/688-5412.

Sometimes, producers can afford to spend a lot to improve herd health. Sometimes not. A University of Missouri-Columbia study analyzed five years' records on a well-managed beef operation and found big differences in economic benefits of health care from year to year.

"From the best to the worst health year, mortality ranged from 4.7 to 12 percent and the morbidity (sickness) ranged from 15 to 85 percent," says Extension veterinarian Bob Larson.

"When we took those data into consideration and figured the going price for cattle and calves, there were some years and some levels of calf disease when the producer could only return investments of $4 to $8 per head. But, there were other situations when he could have spent $11 to $23 per animal and still have been ahead," Larson reports. On average, producers could afford to increase expenditures by $7 to $14 per cow if rates of calf illness and death could be lowered.

"By identifying the potential payback from a neonatal health plan and figuring its costs, veterinarians and their clients can develop a strategy that has the greatest chance for payoff," Larson says.

For more information contact Bob Larson, University of Missouri, at 573/882-7848.

One way to a cow's stomachs is through her nose, researchers suspect. That's why scientists at the University of Illinois (U of I) have developed a way to measure the impact of odor on feed intake.

"When we're trying to boost feed intake, either in early lactation or when we're offering less palatable feeds, we may be able to manipulate odor to get cattle to eat more," says Robert Corley, III, a doctoral student working on the project. He explains that odor, flavor, texture and other factors all have an impact on how well a cow likes a feed and how much she eats. "There just hasn't been a lot of work done on odor," he says.

Corley and other U of I students modified a machine, first researched in 1919, which blows various odors across identical feed options available to cattle. They developed carriers for the odors and a statistical procedure for ranking cows preferences for various odors.

"The test is similar to the taste trials used to test humans' preference for food products," Corley explains. Although preliminary results are inconclusive, they do suggest that odor does have an impact on feed intake.

For more information contact Robert Corley, III, University of Illinois, at 217/333-0093. l