Systemic bone growth factors in light breed mares and their foals

There is a high incidence of bony pathology in race horses. Thus, plasma GH, IGF-1, osteocalcin (OC), calcium (Ca) and inorganic phosphorus (P) concentrations were measured in 12 healthy Selle Français foals and their dams during the first five months after birth. Plasma IGF-1 and OC concentrations were higher in foals than in mares (336 +/- 25 vs 230 +/- 18 ng/ml, P < 0.05; 52.5 +/- 3.2 vs 4.9 +/- 0.1 ng/mg, P < 0.01, respectively). A significant positive linear relationship could be established between these two parameters in foals (IGF-1 = 19 + 0.619 OC; P < 0.05). Another striking evidence was the increase in plasma IGF-1, OC and P concentrations observed during the first week of postnatal life. IGF-1, OC, P and Ca concentrations remained elevated during the experimental period, indicating an intense skeletal growth (confirmed by growth curve) in these animals.