Cattle are generally in good body condition and good health across Louisiana, but producers need to stay alert for potential problems, according to LSU AgCenter veterinarian Steven S. Nicholson.
Anaplasmosis and pneumonia are not uncommon causes of illness and death in adult cattle in the fall. Dead animals should be necropsied by a veterinarian to determine cause of death. Cattle may exhibit unusual behavior because of oxygen depletion accompanying the severe anemia produced by anaplasmosis.
Nicholson says it is not unusual for some herds to experience baby calf losses at the beginning of fall calving. Losses include stillborn calves with no apparent cause and calves that experienced infection in early pregnancy. Viruses such as BVD and bluetongue are sometimes implicated as the cause of nervous system or skeletal defects.
“Fall is a time of increased risk of poisoning caused by toxic plants,” Nicholson says. Sicklepod and coffee senna produce marked muscle damage, coffee-colored urine and affected animals are down, unable to stand. Coffee senna is often browsed the morning after the first killing frost.
The LSU AgCenter veterinary also notes that in southeast Louisiana, some cattle herds and horses may have access to showy crotalaria, which contains a potent liver toxin. This plant stands upright on a single stalk, is 2 to 4 feet tall, has yellow flowers and produces large seed pods. Liver failure may not become apparent until weeks or months after the plant is eaten.
The fruit of the tung tree is on the ground in southeast Louisiana and may be eaten by hungry yearling age cattle. It produces severe inflammation of the digestive tract and is often fatal.
In some areas an abundant crop of acorns may be dropping from oak trees. Cattle may develop an appetite for green acorns and eat as much as one-half of their diet for a week or two if that many are available. Oak poisoning results in kidney failure, digestive system damage and death within one to two weeks.
Toxins in ergot-infected seeds of dallisgrass cause muscle tremors and marked incoordination. In heavily infected pastures, seed heads can be removed by clipping with a rotary mower before grazing or cutting hay. A rare condition in bermudagrass produces tremors and incoordination as well.
Nicholson says care should be taken when introducing supplemental feed such as grain or other carbohydrate source. Cattle need several days to adjust to a gradual increase in feed.
Nicholson urges cattle owners to obtain a veterinarian's diagnosis when health problems occur in their animals. AgCenter Extension agents can assist with identification of suspected toxic plants. Local offices can be found on the LSU AgCenter Web site at www.lsuagcenter.com.