Evaluation of Four Different Methods of Calf Birth Weight Data Collection1

Reporting accurate calf birth weight is important for accurate calculation of birth weight and calving ease expected progeny differences. Calf birth weight information is used by many cow-calf producers as an indicator trait for calving ease in animal selection and culling decisions to minimize the risk of dystocia in their herds. The objectives of this study were to 1) evaluate the accuracy of the following birth weight collection methods: estimation via visual appraisal, estimation using hoof circumference tapes, measurement with handheld hanging spring scales, and measurement using digital scales; and 2) determine if visual birth weight estimations change in accuracy with increasing operator experience as the calving season progresses. Within the first 24 h of life, birth weight estimates and measurements were collected on each calf (n = 587) born at the Mississippi Agricultural and Forestry Experiment Station, Leveck Animal Research Center (Mississippi State, MS) and the Prairie Research Unit (Prairie, MS) during routine calf tagging and processing over a spring and autumn period at each location. Results indicate that birth weight records can vary because of the birth weight collection method used. When birth weight levels were examined, visual estimates and hoof tape measurements tended to underestimate high birth weights, whereas hoof tape measurements tended to overestimate low birth weights. Birth weight data collection via either spring or digital scales resulted in more accurate measurements.