Investigation of the positions of corpus luteum and fetus and their relationship with blood metabolites in pregnant and non-pregnant Lori-Bakhtiari ewes

Different metabolites such as glucose, cholesterol and urea nitrogen of serum are important indices for protein and energy status in sheep. It was shown that, the concentration of serum metabolites change at the different times of reproductive activities and also in the pregnant ewes with one or two fetuses. Therefore, the aim of this study was to investigate the effect of different corpus luteum and fetus positions on serum metabolites in Lori-Bakhtiari ewes.
This study was conducted on the pregnant and non-pregnant ewes. At the beginning of the experiment Lori-Bakhtiari ewes (3 to 4 years of age) were chosen at abattoir. Then, the blood samples were collected before slaughtering and transported to the laboratory for evaluating glucose, cholesterol and urea nitrogen concentrations of serum. The first part of the study was conducted in out-breeding season and 48 non-pregnant ewes reproductive tracts were collected and divided into 3 treatment groups as follow: group 1 with one corpus luteum; group 2 with two corpora lutea (unilateral) and group 3 with two corpora lutea (bilateral). The second part of this experiment was conducted in the breeding season and 144 reproductive tracts were collected and divided into 9 treatment groups as follow: group 1 with one corpus luteum and non-pregnant; group 2 with two corpora lutea (unilateral) and non-pregnant; group 3 with two corpora lutea (bilateral) and non-pregnant; group 4 with one corpus luteum and one fetus; group 5 with one corpus luteum and two fetuses; group 6 with two corpora lutea (unilateral) and one fetus; group 7 with two corpora lutea (bilateral) one fetus; group 8 with two corpora lutea (unilateral) and two fetuses and group 9 with two corpora lutea (bilateral) and two fetuses.
This study indicated that among the experimental groups the maximum concentration of serum glucose was observed in the ewes with one corpus luteum and one fetus and the minimum concentration of serum glucose was observed in the ewes with two corpora lutea (bilateral) and two fetuses (P 0.05) between the ewes with different positions of corpora lutea (unilateral and bilateral) and the ewes with one corpus luteam and two fetuses.
In conclusion, the results showed that serum glucose concentration in out-breeding season was higher than breeding season. Whiles it was lower than in pregnant ewes compared with non-pregnant ewes and also in ewes with two fetuses compared with on fetus. The concentrations of cholesterol and urea nitrogen of serum were higher than pregnant ewes compared with non-pregnant ewes and also in ewes with fetuses compared with one fetus.