Original scientific paper

IGF-I in grazing dairy ewes during late pregnancy and lactation and its correlation to biochemical markers of bone metabolism.

Zvonimir Tuček ; Centre for Animal Reproduction of Croatia, Zagreb, Croatia
Natalija Filipović ; Department of Physiology and Radiobiology, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
Tomislav Mašek ; Department of Animal Nutrition and Dietetics, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
Zvonko Stojević ; Department of Physiology and Radiobiology, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
Nikica Prvanović ; Clinic for Obstetrics and Reproduction, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
Željko Mikulec ; Department of Animal Nutrition and Dietetics, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia

Abstract

We investigated the influence of late pregnancy and lactation on bone metabolism in grazing dairy sheep, by measuring concentrations of minerals and bone markers in blood serum. The research was performed on ten cross-breed ewes (Istrian × East-Friesian). The concentrations of total Ca, inorganic P, total Mg, the activity of total alkaline phosphatase (AP) and bone alkaline phosphatase (BAP), concentrations of carboxyterminal crosslinked telopeptide of type I collagen (CTx), insulin-like growth factor - I (IGF-I) and 17- β estradiol (E2) were determined in the blood serum. The results showed significantly lower Ca concentrations in blood during lactation and P concentrations in the period of late lactation. Late lactation was characterized by the lowest CTx concentration and higher BAP activity. The obtained results are related to a decrease in the degree of bone resorption and an increase in the deposition of minerals in the bone tissue during late lactation. The increased concentration of CTx, with the simultaneous decrease in BAP activity in the period of late pregnancy and early lactation indicate a high magnitude of bone resorption. The concentration of IGF-I in the blood serum of the ewes is positively correlated with the activities of the total AP and BAP and the total Ca and Mg, which could be related to the activity of IGF-I on the osteoblasts and the release of minerals from the bones. The results of the present study show a relationship between concentrations of IGF-I and bone remodelling markers in the blood serum of dairy ewes, and their mutual correlation with changes in estradiol concentration.

Keywords

IGF-I; bone biochemical markers; dairy ewes; pregnancy; lactation

Hrčak ID:

125062

URI

https://hrcak.srce.hr/125062

Publication date:

16.7.2014.

Article data in other languages: croatian

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