Diarrhea in newborn dairy calves causes 62% of annual calf mortality and represents a large economic loss to the dairy industry, says Jud Heinrichs of Penn State University. Heinrichs spoke Monday at Alltech's 24th International Animal Health and Nutrition Symposium in Lexington, Ky.
"Viral pathogens destroy villus architecture and decrease the absorptive surface area of the small intestine," Heinrichs told the audience. "Loss of epithelial function results in poor absorption of water and other nutrients. Continued diarrhea increases the risk of dehydration and hypoglycemia and, if not treated, can lead to death."
According to Heinrichs, 8% of all live dairy heifer calves born in the U.S. die each year.
"Dairy heifer calves cost $700 each," he notes, "So, an 8% death loss is a huge loss for a dairy."
In their first 10 days of life, newborn calves rely on passive transfer of antibodies through colostrum from vaccinated cows.
Heinrichs says dairymen need to boost calf survival rates by decreasing the incidence of scours. To accomplish this, they should:
* Separate calves from their mothers quickly
* Feed them 1 gallon of high-quality colostrum within the first four hours of birth
* Raise the calf in a clean environment.
In addition to immunities to several bacteria that cause scours, colostrom is a good source of nucleotides.
"Nucleotides are NPN compounds found in many foods such as seafood, legumes, yeast cell contents and organ meats," Heinrichs says. "Nucleotides are often called "semi-essential" nutrients for young animals. Although the body is able to synthesize nucleotides, intestinal tissue that is developing or diseased requires supplemental nucleotides beyond what the body can normally produce."
In a study conducted at Penn State University, newborn calves received milk replacer supplemented with nucleotides. Results of the study showed calves on this diet had enhanced intestinal integrity, increased small intestinal absorptive capacity, an increased number of good bacteria in their intestines, decreased incidence of diarrhea and improved calf health without antibiotics, compared to calves not supplemented with nucleotides.
"Calves supplemented with nucleotides had longer intestinal villi and a more beneficial intestinal environment due to higher concentrations of L. acidophilus and Bifidobacteria," Heinrichs concluded. "Further evaluation of diet supplementation with yeast cell contents may lead to better calf health by improving intestinal morphology and function."