Heart rate is one way to tell if the calf is in respiratory distress, since it drops as the body is deprived of oxygen. Normal heart rate in a newborn calf is 100 to 120 beats per minute. Place your hand over the lower left side of the ribcage, just behind and above the elbow of his front leg. If heart rate has dropped as low as 40, the calf ’s condition is critical; he needs to start breathing immediately.