Akademik Veri Yönetim Sistemi
Revista Cientifica de la Facultad de Veterinaria, cilt.36, sa.2, ss.1-6, 2026 (SCI-Expanded, Scopus)
This study compared the performance of the Brix refractometer and radial immunodiffusion for assessing passive transfer immunity in Holstein calves and examined the relationship between passive transfer immunity and early body weight gain during the first 72 hours of life. A total of 136 Holstein calves that received ≥ 3 L of high-quality colostrum (Brix ≥ 22 %) within 30 minutes after birth were included. Blood samples for immunoglobulin G and Brix readings were collected 36–48 hours post-birth, and body weight was recorded at 0, 24, 48, and 72 hours. Two immunoglobulin G thresholds were applied: 24 g/L (‘excellent’ passive transfer immunity; Group 24) and 18 g/L (‘adequate’ passive transfer immunity; Group 18). Correlation analyses were performed between radial immunodiffusion and Brix values, as well as between immunoglobulin G and body weight gain indices across intervals (0–24, 0–48, 0–72, 24–48, 24–72, 48–72 hours). Significant correlations were found between Brix and radial immunodiffusion (r = 0.804; P < 0.001), confirming the reliability of the refractometer for field use. Mean immunoglobulin G concentrations differed significantly between low and high groups for both thresholds (P < 0.001). No significant immunoglobulin G differences were observed by gender (29.54 ± 1.26 vs. 28.04 ± 1.17 g/L; P = 0.432) or birth weight (≤ 38.7 vs. > 38.7 kg; P = 0.466). Correlations between immunoglobulin G and body weight gain were weak and nonsignificant (P > 0.05). body weight gain did not differ by passive transfer immunity category, although males showed slightly greater weight loss at 24–48 hours (P = 0.026) and higher gain at 48–72 hours (P = 0.048). Overall, the Brix refractometer strongly correlated with radial immunodiffusion, validating its practical use, but early body weight gain was not a reliable indicator of passive transfer immunity status.