(C) Week 5: How is early disease detection optimized in your population?

The health of dairy calves early in life (their first 8 weeks) directly impacts future milk production and longevity in the dairy herd. Protecting the future health and survivability of calves starts with timely feeding of adequate amounts of high-quality colostrum (see section below for key points) and disinfecting the navel with 7% tincture of iodine or a chlorhexidine solution. In addition, dairy calf managers must be able to identify sick calves and provide supportive therapy early for the best survival rates and to minimize effects on long-term productivity

In the 2007 National Animal Health Monitoring Survey, dairy producers and their veterinarians indicated that scours (diarrhea) occurred in 24% of dairy calves prior to weaning and that 12% of calves had respiratory issues (pneumonia). The highest risk for scours occurs within the first month of life. Young dairy calves with scours can become severely dehydrated quickly. If they are not treated in a timely manner, their chances of survival can decrease tremendously. Respiratory issues more often are seen when calves are stressed particularly around weaning time. However, the first episode may be traced to the pre-weaning period.

Excellent dairy calf managers can spot diseases early and treat these calves so they have the best chances of recovering quickly. To help train employees and family members to detect illnesses in dairy calves, we provide a check sheet with common symptoms to evaluate. Once sick calves have been identified and more closely examined, protocols developed with your local veterinarian should be implemented to treat these calves. In addition, reviewing management practices and instituting changes can help prevent illnesses in young dairy calves.

* **Feed colostrum** **within 6 hours of birth**. Absorption of antibodies decreases with age and is essentially non-existent by 24 hours of age.
* **Hand-feed an adequate amount of colostrum** –- 4 quarts to Holsteins; 3 quarts for Jerseys. Studies have shown that first lactation milk yields are higher in calves fed 4 quarts versus 2 quarts of colostrum at birth.
* **Feed high-quality colostrum**where quality has been measured (i.e., with a colostrometer) and feed to provide a total of 100-150 g IgG.
* **Make sure bacteria counts are low in colostrum.** Milk colostrum into a clean bucket from cows prepped for milking. Feed colostrum within 1 hour of collection, or refrigerate or freeze it immediately upon collection. Use clean plastic bottles filled with frozen water to lower the temperature of colostrum at harvest before/while being refrigerated or frozen.
* **Remove calves from dams at birth**to avoid suckling around legs and brisket, which can result in the consumption of manure.

How can you identify potentially sick calves?

During feeding time:

1. Does the calf get up and actively position itself at it's milk feeding station?
2. Does the calf want to drink it's milk?
3. Does the calf drink it's milk at a normal expected rate?
4. Are the calf's ears erect? Is the calf alert?

If any of these questions are answered with "no" the calf should be examined more closely using these questions:

1. What is the calf's manure consistency?
2. What are the calf's vital signs?
3. Is the calf dehydrated? (skin tent test)
4. Are the calf's gum dry or white?
5. Is it's heart rate elevated?
6. Is the calf breathing rapidly?

How to prevent illness in young dairy calves:

* Make sure sick calves are fed last
* Wash your hands and boots before and after feeding/handling calves
* Ensure calf buckets and bottles are washed properly
* Are calves provided a shaded environment when in hutches? (trees or shade cloth to block the sun on days over 75\*F
* Ensure calves are housed in an environment that is dry and draft free, but still provide adequate ventilation
* Ensure clean & dry bedding is provided for each calf especially as the weather gets colder
* Ensure calf hutches are moved and sanitized in between different calves
* Discuss different vaccination, & handling protocols to prevent disease outbreaks in your operation

References:

* "Early Identification of Sick Dairy Calves Important to Their Survival and Future Milk Production." *EXtension*. N.p., n.d. Web. 26 Feb. 2017. http://articles.extension.org/pages/65519/early-identification-of-sick-dairy-calves-important-to-their-survival-and-future-milk-production