Managing newborn calf health – Part 2 (Proceedings)

It should be a common philosophy among dairy veterinarians that it is far preferable to get off to a good start and assure/maintain health than to make up for deficiencies later and treat disease. With these principles in mind it is important to recognize that the overwhelming majority of all dairy calves delivered in the U.S. will be attended by dairy personnel rather than veterinarians. What takes place during a delivery, and how calves are observed and treated after delivery will depend mainly upon the knowledge, skills, and focus of dairy personnel.

In cases of dystocia, prolonged birth asphyxia can present a significant challenge to the health of the newborn calf. Because removal of the calf from the birth canal is the primary focus of most assisted deliveries, the process is often considered successful when the calf has been delivered, and careful assessment of the calf is often forgotten. There is a strong tendency to assume calves will survive and perform normally, and no specific treatment or monitoring is initiated. Commonly, problems in calves following dystocia are detected long after the optimal time to address them, and the fact that the problems are associated with dystocia goes unrecognized. Better health can be achieved in dystocia affected calves if a routine monitoring system is followed and supportive care is provided before problems develop. The most important first step in improving survival and health of calves following dystocia, is recognizing that all such calves are compromised by the dystocia event.

In the dairy industry, the problem of dystocia has traditionally been underestimated, resulting in poorly defined dystocia rates that are seldom studied. Actual dystocia rates for dairy cattle are difficult to find and interpret in the literature, reflecting the lack of attention the topic receives. A recent study evaluated 666,341 calving records and reported dystocia rates for primiparous and multiparous dams over a 12-year period. They estimated a primiparous and multiparous dystocia rate (score>1) of 28.6% and 10.7%, respectively. Our recent study of the impacts of dystocia on calf health and survival included dairies with overall dystocia rates above 30%. Since dystocia is a very common occurrence and the negative impacts on calf health are so profound, it is important for personnel to monitor frequently for impending delivery and to know when and how to intervene.

Many veterinarians and producers in the dairy industry have found routine, well defined protocols to be useful tools in dairy management. Delivery management is a prime example of the challenges of protocol implementation. There is great individual variation between cows in the intensity of signs of first stage labor, the duration of first stage labor, and the rate of delivery of the calf during second stage labor. For workers to apply delivery protocols with good judgment requires that they be well educated about the delivery process, what to look for as normal versus abnormal delivery, what time periods are appropriate for waiting versus action, and how to observe cattle without disturbing their delivery. In the event that close physical examination is required, workers need to be well trained in keeping cattle calm and doing vaginal examination with good hygiene.

The ideal way to avoid the negative impacts of dystocia on calves and dams would be to prevent its occurrence. Given the apparent high incidence of dystocia in the dairy industry, efforts to minimize the problem seem well warranted. However, dystocia is a complex problem, without an easy management solution, so whatever efforts are made to promote easy deliveries will certainly not eliminate the problem. When dystocia does occur, prompt and well-directed efforts to assist delivery, as well as postnatal calf care are critical to minimizing the severity of the negative impact on animal health. All personnel involved in calf delivery should be well educated about the process and well trained in appropriate skills and techniques. In our experience, it is uncommon for dairy owners or workers to have been educated and trained about calf delivery methods.

The most critical first step in educating dairy workers about dystocia management is to affirm an appropriate philosophy about goals. Difficult deliveries are commonly seen as problems or accidents or nuisances that need to be dealt with, but that interfere with productive work. It is easy to see how this attitude leads to inappropriate decision-making and behavior, for example: wait and deal with it later; get it over as quickly as possible; the job is done when the calf has been removed from the cow. Looked at from a different perspective, dystocia events are opportunities to provide care to a mother and baby that have a significant challenge. Our goal should be to provide the best, most well directed efforts to assure that both animals meet the challenge and go on to live healthy and productive lives. This philosophy leads to very different decisions and actions than the former attitude.

Learning issues for people delivering calves include a broad range of assessments and activities. Veterinarians have been educated on all of these topics and can share that knowledge with the people who deliver calves on dairies. Important topics include: assessment of the dam; restraint and positioning; hygiene and lubrication; position presentation and posture of the calf; assessment of calf viability; manipulation techniques; guidelines for delivery procedures, including equipment needs, force and direction of pull, timing, and assessment of progress. It is critical for workers to develop the judgment to determine when to proceed, when to wait, and when to call for professional assistance.

A simple but effective monitoring program includes assessment of the dam's health, the type of delivery, the maturity of the newborn, and the physical and behavioral characteristics of the newborn. Calves born from an ill dam or with any degree of dystocia, or that appear premature at birth, will have an increased likelihood of encountering adaptive problems. If these problems are anticipated and treated before they manifest overtly, the likelihood of survival and reasonably good health can be increased dramatically. Such calves can be promptly dried and warmed, provided adequate shelter, stimulated to move about and suckle, and provided colostrum early and for a prolonged duration. Additional treatments to circumvent hypoxemia and acidosis would include nasal insufflation of oxygen and intravenous fluid therapy if the dairy is prepared to provide such care. Hypoglycemia can be easily monitored and managed with intravenous supplementation.

Colostral Management

The importance of colostrum to provide immuno-naïve newborn calves with maternally derived immunoglobulins have been extensively emphasized in the veterinary literature for a considerable time so will not be further explored here. However, the benefits of colostrum to calves go well beyond the provision of antibodies. Dairy workers should be educated that a good colostral management program is critical to newborn calf health for many reasons. Colostrum provides a very concentrated source of critical nutrient elements to the newborn, including numerous micronutrients as well as high levels of energy. Colostrum also provides the first source of fluids, necessary to expand blood volume. Properly warmed it is also an important source of heat for the baby calf. Recent research has focused on some of the immune-protective factors besides antibodies, such as non-immunoglobulin proteins and maternal immune cells.

An additional note is warranted concerning colostrum consumption. Calves born in dystocia or with physiological disturbances from some other cause are more prone than their normal counterparts to poor colostral immunoglobulin protection. This tendency is attributable to numerous factors including delayed or decreased consumption of colostrum, decreased colostrum availability due to problems with the dam, and decreased intestinal absorption due to poor gastrointestinal activity or poor mucosal absorptive capacity. A calf's disease susceptibility is also increased by some of the physiological disturbances mentioned in the paragraphs above. This combination of factors is in part responsible for the increased infectious disease occurrence seen in dystocia-affected calves. Even when the problems discussed above have been properly addressed, special attention should be given to increasing colostral administration to these calves. It has been demonstrated that hypoxemic and acidotic calves display decreased immunoglobulin absorption but also delayed closure of the absorptive process. For this reason, it is worthwhile to supplement colostrum for a prolonged time period.

Worker Training and Education

Calving management and newborn calf care should be seen as critical elements of a dairy health program. The events that occur on the day of delivery have a profound influence on the health and survival of calves. Optimal management of these events requires good judgment and decision-making as well as appropriate skills. As dairies get larger most decisions and activities in the calving management arena are made by paid employees. Higher rates of success require that these employees are well educated about the process so that they can make good decisions, well-trained in techniques so they can perform tasks appropriately, and provided with good protocols and facilities so that procedures are done properly.

In our experience, when these prerequisites are met, calf losses can be reduced by 50% or more. One difficulty for practicing veterinarians who wish to train dairy workers is assembling the appropriate learning objectives and teaching materials for their audience. We have assembled a set of teaching materials for use by veterinarians on the Integrated Livestock Management website at Colorado State University. This information can be accessed at www.cvmbs.colostate.edu/ILM and found under the heading producer information.