LOUISIANA CATTLE appear to be in pretty good shape as winter approaches, but LSU AgCenter veterinarian Steven S. Nicholson said there are a few exceptions.
Nicholson also said it's time for cattle producers to plan ahead to prevent such wintertime problems such as pregnancy toxemia, downer cows and grass tetany.
“Some herds are experiencing outbreaks of diarrhea affecting mature animals,” Nicholson said of some of the exceptions to the general rule that most Louisiana herds are in good health and body condition. “Mortality from such problems can be 5 to 10 percent, depending on the cause.”
Various causes of diarrhea include virus infections, salmonellosis, toxic plants and stomach worms, Nicholson said, adding that successful treatment requires prompt diagnosis.
Sporadic cases of anaplasmosis, a disease which peaks in the fall, also are still occurring and are killing cows and bulls in south Louisiana, according to the LSU AgCenter veterinarian, who said annual vaccination of valuable herd bulls is recommended.
Moving to other problems that occur this time of year, Nicholson said ingestion of toxic plants, including sesbania seeds, crotalaria and the fruit of the tung oil tree, may be the cause of severe diarrhea and dehydration.
And he said acorn poisoning has affected several herds in the region.
“Dry weather and frost in recent weeks led to depletion in quality and volume of summer grass,” Nicholson said. “Fat cows in late pregnancy suddenly forced to eat a diet of low-protein, high-fiber forage may develop pregnancy toxemia. Rapid weight loss, lethargy and death occur in pregnancy toxemia.”
The veterinarian also said lactating cows grazing ryegrass and wheat pasture may need additional dietary magnesium each day to prevent a condition called grass tetany. Affected cows become nervous, easily excited, develop convulsions and die unless treated.