The invention includes a system and method for predicting the performance of production animals by analysis of heart and lung sounds to determine likelihoods the animals will develop BRD or other diseases or ailments. Vital signs of animals are recorded during an adrenergic sympathetic "flight or fight" situation. A cardio-pulmonary rate ratio is determined for each animal by dividing a normalized adjusted heart rate value by a normalized adjusted respiratory value. From the ratios calculated for each animal in a group, a ratio range is established. Ratio values at a lower end of the ratio range indicate higher relative respiration rates and poor lung performance due to disease. Ratio values at an upper end of the range may indicate low cardiac output and an inability to tolerate rapid weight gain. Ratio values at either end of the range may indicate compromised cardio- pulmonary function. Animals can be further classified by weight, and the ratio values within weight classes are used to generate probabilities for BRD or other diseases.
