Serum IgG threshold values associated with increased risk of diseases in preweaned lambs

Serum IgG cut-off points associated with increased risk of septicemia, fatigue anorexi syndrome (FAS), diar- rhea and pneumonia in preweaned lambs was investigated in this study. The study involved 347 Akkaraman crossbred lambs born on two farms in Kars, Turkey. Blood samples were collected 24±1 h after birth and serum IgG concentrati- on was measured by ELISA assay and cut-off values for each disease were determined. Neonatal lambs with diarrhea, FAS and septicaemia had statistically significantly lower IgG concentrations compared to healthy lambs (P<0.05). Cri- tical SIgGC-24 cut-off values for increased risk of diarrhea, FAS and septicaemia in neonatal lambs were <800, <1000 and <200 mg/dl. In post-neonatal period, SIgGC-24 (mg/dL) was lower in only lambs with pneumonia compared to he- althy lambs (P<0.05). The risk of developing septicaemia (IgG<200 mg/dL vs IgG>200 mg/dL), diarrhoe (IgG<800 mg/ dL vs IgG>800 mg/dL), FAS (IgG<1000 mg/dL vs IgG>1000 mg/dL) and pneumonia ((IgG<1000 mg/dL vs IgG>1000 mg/dL) was 203, 6, 18 and 12 times higher, respectively. A threshold vaule of IgG<998 mg/dL and IgG<193 mg/ dL were determined for neonatal morbidity and mortality, respectively. An appropriate colostrum management may help to maintain the health of pre-weaning lambs, thereby improving the productivity and profitability of sheep farms..