Preovulatory follicular fluid and serum metabolome profiles in lactating beef cows with thin, moderate, and obese body condition.

Extremes in body condition affect fertility and pregnancy outcomes in beef cows. Much research has been done in women and dairy cows to evaluate body condition's effect on oocyte and embryo quality, pregnancy rates, and pregnancy outcomes. However, little work of this type has been done in beef cows and most studies do not focus on the preovulatory time period. The preovulatory time period is an essential time for the oocyte, as final stages of prematuration and the completion of oocyte maturation take place in the peri-ovulatory follicle. The follicular fluid provides the microenvironment for oocyte maturation and exchanges substances with maternal circulation at the blood follicular barrier. Alterations in maternal circulation due to extremes in body condition may pass into the follicular fluid and affect the oocyte during the preovulatory time period. Such conditions may contribute to the reduced fertility seen in beef cows with extreme body condition.