Early Identification of Sick Dairy Calves Important to Their Survival and Future Milk Production
Introduction
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.
Critical Control Points for Colostrum Management
- 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.
Identifying Potentially Sick Calves
Step 1: Identify calves needing more careful evaluation at and just before feeding times.
| If you answer "no" to a question below, examine these calves more closely using the questions listed under Step 2: Closer Inspection. | ||
| Yes | No | |
| Does the calf get up and actively position itself at its milk feeding station? | ||
| Does the calf want to drink its milk? | ||
| Does the calf drink its milk at its normal expected rate? | ||
| With automatic feeding stations, does the calf drink its normal allocation of milk within the allocated time frame? | ||
| Are the calf’s ears erect, and is the calf alert? Droopy ears are a sign of illness (See Fig. 1). | ||
Figure 1. An alert calf with erect ears.
| If any problems are detected, calves should be examined more closely using the questions listed under Step 2: Closer Inspection. | ||
What is the calf's manure consistency? Check the description that is the closest. Calves that are scouring need additional fluids and need to be examined more closely and should be fed last to prevent spread of diseases to healthy calves. | ||
Pudding consistency – normal fecal consistency | ||
| Yogurt consistency – fecal consistency does not warrant feeding electrolytes | ||
| Maple syrup consistency and/or strong odor – too thin. Calf needs closer examination, and electrolytes should be fed in addition to and separately from milk. | ||
| Apple juice consistency – too thin. Calf needs closer examination, and electrolytes should be fed in addition to and separately from milk. | ||
| Yes | No | |
| Is the calf coughing and/or has a discharge from its nose or eyes? If so, closer examination of the calf is needed for potential respiratory illnesses. Your veterinarian can help you diagnose the source of the problem and prescribe the best course of action. Antibiotics should be used as directed by your local veterinarian. | ||
Figure 2. Everting a calf's lower eyelid
Step 2: Closer Inspection (for calves with potential illness detected through questions answered in Step 1)
| If a calf’s vital signs are outside the normal range (that is, you have answered "yes" to any question), implement treatment protocols that have been developed with the help of your local veterinarian. | |||
| Yes | No | Normal or expected calf vitals | |
| Is the calf’s temperature elevated? | 101° to 103°F is normal | ||
| Is the calf breathing rapidly? | 24 to 26 breaths per minute is normal in calves less than 1 month of age and 15 to 30 breaths per minute in older calves | ||
| Is the calf’s heart rate elevated? | 100 to 140 beats per minute is normal in calves (twice as fast as a cow). An irregular heart beat is one sign of illness. | ||
| Are the calf’s eyes sunken into the eye socket? (Gently evert the calf's lower eyelid and observe the amount of space between the eyeball and the lower eyelid.) | Healthy calves have a minimal amount of space between the lower eyelid and eyeball (less than 2 mm or a little more than 1/16th of an inch). As the calf becomes dehydrated, the amount of space between the eyeball and lower lid increases. (See Fig. 2) | ||
| When the skin of the neck is pinched and gently rotated 90°, a tent of the skin forms. Does this skin tent return to normal within 2 seconds? (See Fig. 3) | Normally, expect the tenting of skin to return to normal within 2 seconds. | ||
| Are the calf’s gums dry and white? | Normally, a calf’s gums are moist and pink. Dry, white gums are a symptom of severe dehydration (8-10% dehydration). | ||
| If the calf is lying down, does it fail to get up when given a small amount of persuasion? | For calves that are unable to rise, contact and/or follow your veterinarian’s recommendations immediately. These calves may need IV fluids (fluids administered directly into the blood) to help treat the dehydration and possible acidosis. If not treated appropriately and quickly, this calf may die. | ||
Figure 3. Performing a "skin tent" test. On a healthy calf, the skin should return to normal within 2 seconds.
Electrolytes Important for Scouring Calves
Calves can lose 5% to 10% of their body weight daily in fluids due to scours. To replace these lost fluids, electrolytes should be fed in addition and separately to the calf’s allocation of milk. Electrolytes alone do not provide an adequate amount of energy for the calf to fight off the disease and maintain body weight. To determine if additional treatments (i.e., antibiotics) are needed to help the calf recover from scours or pneumonia, farmers should work with their local veterinarian to develop treatment protocols that reflect the needs and diseases seen on their dairy operation (known as standard operating procedures, or SOP).
Calf Symptoms1 | % dehydration | Daily amount of electrolytes needed for 100-lb calf** | Total daily amount of fluids (milk plus electrolytes) |
| 5-6 % | 3 quarts of electrolytes plus 4-6 quarts of milk | 7-9 quarts |
| 6-8% (moderately dehydrated) | 4 quarts of electrolytes plus 4-6 quarts of milk | 8-10 quarts |
| 8-10% (severely dehydrated) | IV fluids needed to provide adequate fluids and to correct blood pH caused by imbalance of acids and bases in the blood (known as metabolic acidosis) | Contact veterinarian and follow his or her advice |
| Over 14% |
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* Overfeeding electrolytes causes little detriment to calves. However, underfeeding electrolytes can prolong scours and not correct the dehydration and loss of electrolytes. | |||
| Instituting key management practices can help prevent illnesses in young calves and minimize their spread. Below is a check sheet identifying some of the areas to review on a regular basis to help prevent illnesses in calves. | |||
| Management practices | Why this practice is important | ||
| Yes | No | ||
| Are sick calves fed last? | When sick calves are not fed last, diseases can be transmitted to healthy calves. | ||
| Do you wash your hands and boots before and after feeding and/or examining/handling calves? | Several calf diseases are transmissible to humans in addition to other calves. In addition, fecal contamination is the most likely cause in the spread of infectious agents causing scours. | ||
Are calf buckets and bottles for feeding milk washed according to the following procedures after each feeding?
| To prevent bacteria growth in feeding equipment and the spread of disease, follow the same washing procedures for cleaning milking equipment used to harvest milk for human consumption. | ||
| If an esophageal feeder is used, is it washed after each use according to the procedure listed above? A small brush should be used to clean the tubing. Store clean and keep dry. | |||
| Are sick calves given their allotment of milk in addition to electrolyte solutions? | Scouring calves need nutrition provided by milk. Calves that are not provided with milk often get weaker, may not respond to treatment, and do not grow as well as those provided with their daily allocation of milk. | ||
| Are electrolytes given when calves have scours and/or are dehydrated? | Scouring calves can lose 5% to 10% of their body weight in water from scouring in one day. Electrolyte solutions are needed in addition to milk to provide fluids and maintain blood pH. Overfeeding electrolytes causes little detriment to calves. However, underfeeding electrolytes can prolong scours and not correct the dehydration and loss of electrolytes. | ||
| If calves are housed in calf hutches, are they provided shade (shaded by trees or shade cloth that blocks greater than 80% radiation) when daytime temperatures are over 75°F? | Calves that are heat stressed have a lower growth rate and immune response when challenged by disease-causing agents. | ||
| Are calves housed in an environment that is dry and draft-free, but provides adequate ventilation at the calf pen level? | To prevent the spread of disease in a calf housing facility, pens need draft-free ventilation and dry bedding. | ||
| Is clean, dry bedding provided for each calf, especially as the weather gets colder? | Within the first 3 weeks of life, the thermal neutral zone for calves is between 60° and 77°F because they are born with little body fat to keep them warm. After 3 weeks of age, the lower critical comfort temperature drops to 50°F. When temperatures drop below these levels, deeply bedding calves with straw can help keep them warm. | ||
| Are calf hutches moved and washed and sanitized between calves? If calves are group housed with an automatic feeder, are facilities and feeder cleaned and sanitized after each group of calves? | Cleaning and sanitizing calf housing between calves prevents the spread of disease. The most common method for transmission of agents that cause scours is through ingestion of fecal matter. | ||
| Do you have protocols established for handling calves that become sick? | Establishing a sound working relationship with your local veterinarian is critical. Utilizing his or her help in establishing standard operating procedures for sick calves can help speed the recovery of calves and result in prudently using antibiotics and other treatment protocols on your dairy operation. In addition, vaccination protocols need to reflect diseases and conditions on your operation. Your local veterinarian’s advice is critical when developing these protocols. | ||
| Have you reviewed these protocols with your local veterinarian? | |||
| Have you discussed with your local veterinarian vaccination protocols needed to prevent problems in your operation? | |||
Author: Donna M. Amaral-Phillips
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