Validation of body condition scores with ultrasound measurements of subcutaneous fat of dairy cows.

This research validated body condition scores with ultrasound measurements of subcutaneous fat. Fifty Holstein cows were evaluated during three sessions in 1993. Cows scored during each session were divided into three groups of 15 or 20 cows. Body condition scores were assigned by one trained individual, utilizing a five-point (1 = thin to 5 = fat) visual scoring technique. Cows were scored to the nearest quarter point. Ultrasound measurements of subcutaneous fat were obtained by another individual at the lumbar, thurl, and tailhead areas of both sides of the cow. Body condition scores and ultrasound measurements were collected on the same day, but obtained independently. Correlations between ultrasound measurements ranged from .36 to .86. Regression models were developed to validate the body condition scoring technique across the three cow groups. Group number and different combinations of ultrasound measurements were independent variables, and body condition score was the dependent variable. Ultrasound measurements were significantly associated with body condition scores. The coefficients of determination for the models ranged from .36 to .65, depending on which ultrasound measurements were included in the model. These results suggest that the body condition scoring technique used in this study was as valid as ultrasound techniques for measurement of subcutaneous fat.