Broiler chicks fed a diet of ground wheat can succumb to an intestinal bacterium that causes disease. But a tiny amount of pine shavings can reduce that risk, ARS and university studies suggest. This could be especially welcome news to southeastern poultry producers. As a feed source, locally grown wheat helps cut the cost of shipping in corn from the Midwest. For the young birds, ground wheat is as nutritious as corn. Scientists found wood shavings supply fiber to help the wheat pass through the chick's intestinal tract. Otherwise, the grain collects there and stagnates. This promotes rampant growth of a natural bacterium called Clostridium perfinges. This organism causes necrotic enteritis--intestinal lesions that can impede the chicks'digestion or even kill them. In studies, the scientists started 14- and 21-day old chicks on diets of corn, ground wheat by itself, and wheat with pine shavings. They infected one group of birds on each diet with the bacteria. Chicks fed only wheat had many lesions. Those fed only corn had few or none, and the chicks fed wheat with a four percent concentration of pine shavings fared almost as well. The scientists plan further research before passing on their findings to poultry producers.
Poultry Research Unit, Mississippi State, MS
Scott L. Branton, (601) 323-2230

ARS scientists have found new clues for coping with two problems in the egg industry. The problems are egg contamination with Salmonella and low egg production by older hens. In one study, scientists found that a chicken's natural resistance to Salmonella infection plummets after it is put on a fast for a week or so. Fasting, a common industry practice, causes hens to molt. This triggers hormonal and other changes, restoring up to 90 percent of the hen's egg-laying capacity. In tests, fasted chickens became infected with Salmonella after ingesting as few as 10 bacterial cells. Typically, a chicken becomes infected after ingesting ten thousand or more Salmonella cells in fecal matter shed by an infected bird. But, the increased susceptibility of fasted hens also leaves them more vulnerable to contracting an infection by a less common route--through the air. Plus, the increased susceptibility raises the odds of egg contamination. On average, the odds are low--less than three eggs in ten thousand. But that could be lowered further with an effective alternative to fasting. One method with potential is an experimental low-calcium diet developed at the University of Georgia. Joint studies by the university and ARS found that birds molted with this diet were 100-foldless susceptible to infection.
Southeast Poultry Research Laboratory, Athens, GA
Peter Holt, (706) 546-3442

A new gene-based test can more quickly and accurately determine if U.S. cattle and sheep carry the virus that causes bluetongue. The new tool could help open an estimated $125 million annual export market now closed to U.S. cattle producers. Countries that do not have bluetongue disease bar importation of U.S. cattle, embryos and sperm. The new test can spot the virus in 10 hours. Older tests take two weeks and may require use of hazardous chemicals. The new test would reduce the cost of testing animals destined for export. It first extracts any of the virus' telltale genetic material--called ribonucleic acid (RNA)--that may be in animal blood samples. For easy detection by standard analytical tools, the test reproduces hundreds of copies of the viral RNA fragments.
Arthropod-borne Animal Diseases Research Laboratory, Laramie, WY
William C. Wilson, (307) 766-3600

Raising armies of larkspur myrid bugs may help discourage cattle from munching on poisonous tall larkspurs. In western mountain ranges, more cattle die from eating tall larkspurs than from any other plant or disease. The deaths, control costs and related expenses cost ranchers about $20 million a year. No antidote exists for the plant's toxic alkaloids. In a preliminary test, four cows preferred tall larkspurs undamaged by the myrid, a native species (Hopplomachus affiguratus). Adult myrids, about one-eighth-inch long, use beak-like mouthparts to pierce larkspur leaves and flowerheads, then suck the juices. Injured leaves mottle and wilt; flowerheads won't mature to form seed. Tall larkspurs are the myrid's only known target. The blooms sport a distinctive spur, like their ornamental cousins--garden delphiniums. Researchers want to explore the potential of releasing myrids that would either augment existing colonies or establish new ones. With more myrids around to damage more of the tall larkspurs on a range, cattle may seek different, healthier plants to eat.
Poisonous Plant Research Laboratory, Logan, UT
Michael H. Ralphs, (801) 752-2941

Ticks that transmit Lyme disease to humans may find it deadly to get a free ride on white-tailed deer. That's because of a new deer feeder dubbed "the four-poster." The feeder gets its name from four pesticide-loaded rollers that rub tick-killing chemicals on a deer's head and neck as it sticks its head inside the device to feast on corn. Treated deer help eliminate ticks from wooded areas rather than leaving the pests behind to find another host. Because the deer don't eat the pesticide, this method is safe for use during the October-December hunting season when the majority of black-legged ticks feed on deer. Pesticides used in the rollers are experimental, but researchers say the "four-poster" is more effective than fencing deer out of tick-infested areas. Lyme disease is most prevalent in the Northeast, the upper Midwest and in California. (Patent 5,367,983)
U.S. Knipling-Bushland Livestock Insects Research Laboratory, Kerrville,TX
J. Mathews Pound, (210) 792-0321

Dairy producers should watch for high potassium levels in dry feed rations because ARS researchers have proven that high potassium--not calcium--cause milk fever in cows. This new finding will reduce the incidence of milkfever, which costs up to $20 million in medications to treat affected cows each year. Based on a three-year study of the diets of 60 Jersey cows, the researchers concluded that calcium levels did not play a role in the developmentof milk fever, thus disproving a generally accepted belief in the milk industry.
Metabolic Diseases and Immunology, Ames, IA
Jesse P. Goff, (515) 239-8343