[Serum insulin and glucose concentrations in sheep during late pregnancy in relation to the number and sex of the fetuses].

OBJECTIVE

The objective of this study was to investigate whether the serum concentration of glucose and insulin in the blood of pregnant sheep depends on the number and the sex of the fetuses.

MATERIAL AND METHODS

The presented research was carried out on Pomeranian (n = 42) and Suffolk sheep (n = 42) towards the end of the pregnancy. The following groups were established amongst the Pomeranian sheep: single pregnancies with a female fetuses (n = 19) and male fetuses (n = 10), twin pregnancies with female fetuses (n = 8), male fetuses (n = 8) and fetuses of different sex (n = 7). Similarly, in the Suffolk sheep, the following groups were formed: single pregnancies with female fetuses (n = 9) and male fetuses (n = 12), twin pregnancies with male fetuses (n = 12) and fetuses of different sex (n = 9).

RESULTS

In Suffolk sheep, serum insulin concentration was significantly higher than in Pomeranian sheep (p < 0.05). The average insulin concentration in Pomeranian sheep with a single pregnancy was higher than in sheep of the same breed with a twin pregnancy (p < 0.05). In the Pomeranian breed, the highest insulin concentration was recorded in sheep with male fetuses (p < 0.01). Similarly, in Suffolk sheep, the insulin concentration was higher in sheep with male fetuses than female ones (p < 0.05). On the other hand, the concentration of glucose in Pomeranian sheep, with both single and twin pregnancies and with female fetuses, was higher than in sheep with male fetuses or different sex fetuses (p < 0.05 and p < 0.01, respectively). In the Suffolk breed, the glucose concentration was also higher in sheep with female fetuses (p < 0.05). In Suffolk sheep a positive correlation was found between the birth weight of lambs and their mother's glucose concentration (r = 0.56; p < 0.01).

CONCLUSION

The differences in the concentration of insulin and glucose in the blood of pregnant sheep demonstrated in this study suggest that sex and the number of fetuses may be further factors affecting the energy metabolism in the late stages of pregnancy. Based in the presented findings these differences may depend on the breed and may be related to the birth weight of lambs.