Managing newborn calf health – Part 1 - Assessment (Proceedings)
In the overwhelming majority of cases (except when a veterinarian delivers a calf in dystocia), the owner/herd manager will be the person best positioned to combat newborn calf health problems. Veterinary intervention will generally involve helping to establish and guide a system of newborn calf assessment and monitoring. This system should include specific guidelines on what parameters to evaluate and how to respond when abnormalities are seen.
A description of the normal newborn calf provides the measure against which problems can be compared. Normal calves should be born from an uncomplicated vaginal delivery, should breathe spontaneously, and should show strong activity almost immediately after birth. Any calf born in dystocia should be considered abnormal. Normal newborn calves may reasonably be expected to stand within one hour of birth. The calf's body temperature should not decrease below 101° F. An active suckling reflex should be present, even before the calf has stood, and the calf should have sought after feeding within two hours of birth. The calf should remain attentive, responsive, and strongly active throughout the first two hours of life.
A simple but effective monitoring program would include assessment of the dam's health, the type of delivery, the maturity of the newborn, and the physical and behavioral characteristics of the newborn. Specific monitoring points on all (but especially dystocia) calves should include: Calf vigor, Time to stand, Body temperature maintenance within the first hour, Active suckling. 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. Hypoglycemia can be easily monitored and managed with intravenous supplementation.Calves that encounter adaptive problems without apparent predisposing risk factors can be detected by observation of their behavioral and physical characteristics. Calves that do not follow the normal pattern described above should be carefully monitored for changes in body temperature, physical strength, suckling ability, activity level, and blood glucose concentration. Such observations can be easily made by dairy personnel if they are instructed properly. Prompt attention to the frequently encountered problems of the newborn can dramatically enhance the newborn's chances of survival. Although compromised newborns will occasionally be found without apparent predisposing causes, the repeated appearance of such cases should prompt a thorough investigation of prepartum health and nutrition of the dams. Deficiencies and imbalances of protein, energy, and certain micronutrients may manifest with neonatal weakness and physiological derangement without readily apparent compromise of the dam.
Inactivity or lethargy: A dam with good mothering instincts can frequently stimulate the calf and thus is responsible for increased survival of her calves. Decreased activity is usually characterized by delayed standing and suckling behavior. These two critical activities generate heat and allow the calf to obtain nutrition and immunological support against disease. One of the most basic supportive care procedures for beef calves is to encourage good mothering behavior on the part of the dam. In the dairy industry, management systems mandate that calves be orphaned, so the calf manager must replace the role the dam would play in a more natural setting, so this person must directly intervene and provide that same mothering activity. These are the typical duties of any good calf manager and include rubbing the calf, lifting it to stand, encouraging it to walk about, providing colostrum via nipple feeder, or, if no suckle is elicited after a couple of hours, providing colostrum via esophageal intubation.
Hypothermia: The calf's body temperature is usually 1 to 2° F above the rectal temperature of the dam immediately after birth. The calf's temperature will usually drop to about 102° F within 15 to 30 minutes after delivery. A typical sign of neonatal adaptive problems is a body temperature that continues to drop below this level. As discussed above, there are numerous likely causes of hypothermia that can occur even in very warm surroundings, including hypoxemia, poor circulation, acid base disturbances, and calf lethargy and inactivity. Prompt drying with towels or warm hair dryers, application of heat lamps and heating blankets, as well as shelter from the elements are warranted from any calf suffering from dystocia or that fails to show normal efforts to rise within the first half to one hour after birth.