The dairy industry has made significant progress since 2007 in the implementation and improvement of dairy-calf respiratory-management practices, according to a new survey released by Merck Animal Health. The study reveals advances in diagnostic testing, colostrum management and calf nutrition.
The survey represents the management of more than 775,000 dairy calves and heifers across 23 states. The last survey to include dairy-calf care and management was conducted in 2007 by the National Animal Health Monitoring System (NAHMS). Of the 174 dairy producers surveyed by Merck Animal Health, 83 raise fewer than 1,000 calves, 70 raise 1,000-9,999 calves and 21 raise more than 10,000 calves each year.
“Respiratory disease is costly in both the short- and long-term of the life of dairy animals,” said Tom Shelton, D.V.M., senior technical services manager for Merck Animal Health. “By measuring current respiratory health practices, we can identify ways to improve the health of dairy calves, which plays a big role in overall herd productivity and profitability.”
One of the most notable findings of the survey is the increased use of diagnostic testing on calves both before and after weaning. Twenty-two percent of operations surveyed use tissue sample testing on at least one calf that died of respiratory disease each year, and 72 percent have at least one necropsy performed. The 2007 NAHMS study, by comparison, reports that eight percent of herds have had necropsies performed on calves before weaning and
7.1 percent on calves after weaning, for all causes of death, including respiratory disease.
“Producers are recognizing the value of diagnostic testing of calves,” said
Donald Sockett, D.V.M., Ph.D., epidemiologist/microbiologist at the Wisconsin Veterinary Diagnostic Laboratory. “This is crucial, because the two percent death loss due to respiratory disease currently reported by producers is probably 1.5-2 times larger in reality.”
Colostrum management and calf nutrition
Producers now do a much better job monitoring their calves for failure of passive transfer (FPT) of immunoglobulins than they did four years ago. According to the survey, the number of calf raisers who routinely check for FPT grew to 45 percent from just two percent in 2007.
The survey also shows that producers have responded to the message that calves need to be fed at a higher plane of nutrition and more frequently. Nutrition programs where calves are fed at least 1.5 pounds of milk replacer or five quarts of non-saleable milk or a combination of non-saleable milk and milk replacer are used in two-thirds of small- and medium-sized herds and one-fourth in large herds.
The percentage of producers who pasteurize non-saleable milk fed to calves has grown from 8.4 percent to 72 percent since 2007. Additionally, eight percent of calves are being fed at least three times per day year round, and 14 percent are fed three times per day in the winter.
“These numbers are a significant improvement from the 2007 study,” said Dr. Sockett. “Producers have come a long way in colostrum management and calf nutrition.”
The wide variation in calf age at weaning has not changed since the 2007 NAHMS survey. Age at weaning varies across all herd sizes, ranging from 30 to 120 days. The most common criterion currently used by survey respondents to determine weaning age is calf starter intake. The other major factor is calf size.
Vaccination and treatment protocols
The study calls attention to the need for standardization of vaccination and treatment protocols. Although 80 percent of producers surveyed have been trained by their veterinarians to identify and treat respiratory disease, less than half have veterinary assistance in designing treatment protocols. Additionally, while 96 percent of producers surveyed vaccinate their calves for respiratory disease, there is no consistency in vaccination protocols.
Almost half of the producers surveyed report respiratory disease in their calves before 30 days of age. Sixty-six percent cull calves prematurely because of respiratory disease. The survey also shows that 9.9 percent of preweaned and weaned calves are treated for respiratory disease. In the NAHMS survey, 12.4 percent of preweaned and 5.9 percent of weaned calves were treated for respiratory disease.
“This study points out several opportunities to continue to improve the respiratory health of our dairy calves. Getting them off to a healthy start is critical to their long-term health and productivity. Taking even small steps to improve respiratory health can make a big difference during the life of an animal,” said Dr. Shelton.
Dr. Shelton shares the following tips to improve respiratory health management:
- Feed one gallon of colostrum within two hours of birth and another gallon
12-15 hours later. Monitor colostrum quality and FPT using a hand-held refractometer.
- Have a back-up plan for shortages of high-quality colostrum.
- Maintain average daily gain of 2.0-2.2 pounds for the first six months.
- Provide clean, warm drinking water and a small amount of calf starter beginning at three to five days of age. Do not allow the calf starter to become stale or contaminated with debris.
- Wean calves when they eat two pounds of starter for three consecutive days and have reached growth targets for the liquid feeding stage of the calf’s life.
- House calves with clean, dry bedding and provide adequate shelter with good air quality and protection from heat and cold stress.
- Practice good husbandry skills. Understanding calves and what causes stress will enable a smoother transition to mixing pens.
- Work with your veterinarian to develop vaccination protocols and benchmarks for optimal calf health. Test for respiratory viruses and bacteria if benchmarks are not being met.
- Regularly train new and seasoned employees to effectively identify and treat respiratory disease.
Measurement recommendations apply to Holsteins and can be reduced for colored breeds. Check with your veterinarian for more details.