Volume 59 (2009) Issue: 2009 No#1

Comparision of IGF-1 (insulin-like growth factor-1) levels in bovine serum sampled three times during the day using validated equine IGF-1 ELISA .

Author(s): Mrkun J, Kosec M, Zrimšek Petra

Keywords:IGF-1, dairy cows, ELISA, method agreement

Cows in negative energy balance exhibit reduced fertility, mediated by metabolic signals that influence the reproductive system. Measurement of IGF-1 contributes to the diagnosis of negative energy balance. The aim of this study was to investigate possible variations in IGF-1 levels in samples taken at different times of the day. Equine IGF-1 ELISA was used for measuring IGF-1 in bovine samples. Statistical analysis was applied to the results. Using scatter diagrams fitted with Deming regression lines, we established that paired measurements on samples obtained at different times were close to the line of equality. 90% of the absolute differences were less than the reproducibility coefficient, confirming that the level of agreement between the IGF-1 levels at different times of the day was satisfactory. IGF-1 levels in bovine samples were independent of the time of day at which samples were taken.