IGF1 and hydrops fetalis: This is in agreement with the results of Mirzaei et al. [52] who confirmed that the highest serum concentration of IGF-I in Polish HF cows was found in CC followed by CT and then TT genotypes, which also, was in agreement with the reports of Mehmannavaz et al. [34], Bonakdar et al. [53] and Mirzaei et al. [52] on the Iranian Holstein cattle.