It’s only been five years since the Dairy 2002 Study was conducted by USDA’s National Animal Health Monitoring System (NAHMS), but the recently released Dairy 2007 Study shows that even during this relatively short period some significant changes and trends have occurred in the industry. Dairy veterinarians should pay close attention to this study because it may help reveal opportunities for their dairy clients.

The Dairy 2007 Study collected data on dairy health and management practices from 17 of the nation’s major dairy states (see sidebar). Numerous changes related to increased productivity and the continued consolidation of the industry have occurred during the last five years.

“The steady increase in herd size and productivity has brought several changes to the dairy industry,” says Jason Lombard, DVM, MS, dairy specialist and veterinary epidemiologist with NAHMS. “Some of these changes have been evident for quite a while, such as the increases in feeding total mixed rations, performing forage analysis and milk production. The impact and extent of other changes in the industry, such as vaccine use and bio-security practices, were not evident until data from the NAHMS Dairy 2007 study were analyzed.” Part I of the Dairy 2007 study was released in October 2007, and Lombard says that more reports from the study are forthcoming

Lombard notes some significant changes and trends from the 2002 and earlier NAHMS dairy studies to the Dairy 2007 Study:

1. The percentage of heifers born on operations and raised off the operation increased 50% since 2002 (7.2% versus 11.5%).  

2. The recommended practice of removing calves from their dams immediately after birth increased dramatically from the 1992 study
to the 2007 study (28.0% and 55.9 percent of operations, respectively).

3. Almost three times as many operations evaluated the quality of colostrum in 2007 compared to just five years ago (13.0% versus 5.2%) and fewer operations pooled colostrum (27.0% in 2002 compared with 21.0% in 2007).

4. There was a significant decrease in the percentage of operations that vaccinated for brucellosis (66.8% in 1992 compared to 41.6% in 2007).

5. There was an increased adoption of modified-live BVDV vaccines for heifers (40.7% in 1996 compared with 62.2% in 2007). Lombard says BVDV vaccine use has increased from 58.4% in 1991 to 73.7% in 2007, while leptospirosis vaccination has increased from 56.1% to 67.7% during the same period.

6. There is an opportunity to increase BVDV testing. In 2007 only 4.0% of all operations routinely tested heifer replacements for persistent infection with BVDV. “I think that many producers do not suspect they have the disease and so may not be familiar with the testing,” Lombard suggests. “With the excellent tests available today and our knowledge of the disease, veterinarians can assist producers in eliminating BVDV from their operation.”

7. The percentage of calves born alive as a percentage of cow inventory decreased from 93.4 % in 1996 to 86.0 % in 2007. Lombard believes this reduction can be partially explained by increases in the calving interval and the percentage of stillborn calves. Lombard says that although the increase in stillbirths is receiving attention, efforts in this area may need to be expanded.

8. Although the percentage of unweaned calves that died decreased from 8.7% in 2002 to 7.8% in 2007, the overall percentage of calves that were born but died prior to weaning was almost 15% in 2007 (6.5% stillbirths and 7.8% deaths). “Because of the large percentage of stillbirths and unweaned calf deaths, I think veterinarians could be more involved in calving and calf management,” Lombard says. “Not unlike our own retirement portfolios, heifer calves are the operations’ investment in the future and should be properly monitored and managed.”

9. There is a need to educate producers about reporting adverse drug reactions, as 52.4% of producers in 2007 who observed an adverse reaction to an injection did not report the reaction to anyone, including their veterinarian.

10. Less than five percent of deaths in unweaned heifers, weaned heifers, and cows were necropsied to determine the cause of death.  “This is a huge missed opportunity for the dairy industry. We could learn something from our feedlot counterparts,”  Lombard says. “This information could potentially impact disease incidence on operations. I am not sure that veterinarians or producers are interested or have the time to perform necropsies on a routine basis, but necropsies can be performed by veterinary technicians or properly trained dairy employees, thereby providing valuable information to producers and veterinarians. Veterinarians could take an active role in promoting the use of necropsies and making sure they are performed by skilled personnel in order to improve cow health.”

11. The reported percentage of cow deaths due to lameness or injury increased from 12.7% in 1996 to 20.0% in 2007. “The slaughter ban on downer cows has likely impacted this estimate, but it still highlights the need to re-evaluate the best environment for cows,” Lombard notes. “This combined with the increase in percentage of cows removed for lameness or injury is worthy of further investigation and evaluation by producers and veterinarians.”

12. The percentage of operations that required individual animal testing for new additions decreased from 33.7% in 1996 23.3% in 2007. The percentage of operations that quarantined animals was less than ideal as reported in the 2007 study. “It appears that producers are more likely to quarantine animals that are easy to quarantine such as unweaned calves.”

More reports to come

Although Part I of the 2007 Dairy Study is the most basic of the study’s reports and provides a good overview, future reports will provide more in-depth information about management practices that dairy veterinarians regularly consult with producers on (i.e. reproduction, calf management, milking procedures, etc). “Future reports will also provide prevalence estimates for contagious mastitis pathogens, Mycobacterium avium subspecies paratuberculosis, and Salmonella; and information on passive transfer, calf growth, cow comfort and housing, etc.,” Lombard adds.

Much more information will be released this year and will be available on the NAHMS Web site. Veterinarians and producers can also request hardcopies of Dairy 2007 reports, or reports from other livestock studies. 


What is the 2007 Dairy Study?

In 2007, the National Animal Health Monitoring System (NAHMS) conducted a study of U.S. Dairy Operations. The Dairy 2007 study collected data on dairy health and management practices from 17 of the nation’s major dairy states. These states represented 79.5% of U.S. dairy operations and 82.5% of U.S. dairy cows. Part 1: Reference of Dairy Cattle Health and Management Practices in the United States, 2007 is the first in a series of reports containing national information from the NAHMS Dairy 2007 study and contains information collected from 2,194 dairy operations. Released October 2007, the report provides participants, industry, and animal-health officials with information on the nation’s dairy population that will serve as a basis for education, service, and research. 

View the complete study