Endocrine Abstracts

Transport of farm animals is considered as a key stress factor including multiple stressors as handling or fasting. In humans, compounds for the IGF-system are affected by acute or critical illness or stress. We have asked, if compounds from the IGF-system also may have biomarker potential in farm animals. A total of 80 pigs were transported for 2 h from a commercial finishing farm to the slaughterhouse. Blood samples from 40 pigs were taken before (basal levels) and after shipment and after lairage and slaughter. A control group of 40 pigs without blood collection before slaughtering was investigated to determine potential effects of blood sampling on parameters in slaughter blood. In plasma, IGF-1 and IGF-binding proteins (IGFBPs) were analyzed using ELISA and quantitative Western Ligand Blotting. The ratio of IGF-1 to the total amount IGFBPs was calculated to examine the IGF-1 bioavailability. Shipment severely reduced plasma IGF-1 (P<0.01) in pigs if compared to pre-shipment conditions. IGFBP-3 and -2 concentrations decreased with prolonged time leading to reduced (P<0.01) concentrations in slaughter blood compared to basal levels. In contrast, IGFBP-5 was increased (P<0.001) after shipment but normalized after lairage and slaughter. The ratio of IGF-1/IGFBPs, and thus IGF-1 bioavailability was reduced (P<0.01) after shipment but not after lairage or slaughter. Repeated blood sampling increased concentrations of IGFBP-3 and IGF-1 compared to controls. The results indicate that acute stress factors during shipment or repeated blood sampling induces changes in somatotropic axis. Our findings indicate that the somatotropic axis may have biomarker potential for defined conditions of stress, which may be useful in order to improve animal health and welfare in pigs.