Relationship of Lactate Dehydrogenase Activity with Body Measurements of Beef Cows and Calves1

Angus × Charolais cows (n = 87) and calves (n = 86) were utilized to examine relationships among lactate dehydrogenase (LDH) activity and age, sire breed, and body measurements of beef cows, and the relationship between maternal LDH activity in late gestation and subsequent calf birth weight (BRW), hip height at weaning (CALFHH), and adjusted weaning weight (205WW). At 62 d prepartum, cow BW, BCS, and hip height (COWHH) were recorded, and cow LM area (LMA), intramuscular fat percentage, and rib fat were measured via ultrasonography. Serum was collected from each cow and forward LDH (LDHf) and reverse LDH (LDHr) activities were determined. Correlation coefficients showed an inverse relationship between cow LDHr activity with CALFHH (r = −0.28; P = 0.01) and 205WW (r = −0.21; P = 0.05) of calves. First canonical correlation of cow LDHr and LDHf activities, BW and COWHH with 205WW and CALFHH was significant (r = 0.57; P = 0.001). The cow traits including LMA, rib fat, and intramuscular fat percentage were correlated (r = 0.36; P = 0.02) with 205WW and CALFHH. A combination of cow LMA, LDHr activity, BW, and COWHH was correlated (r = 0.58; P < 0.001) to a combination of 205WW and CALFHH. Decreased LDHr activity in prepartum cows was associated with taller and heavier calves at weaning. Ultrasonography of LMA, and LDHr activity along with BW and COWHH of cows during the last trimester of pregnancy could be useful in identifying calves with subsequent increased weaning weight.