The Developmental Potential of Oocytes is Impaired in Cattle with Liver Abnormalities

Abstract

Here, we investigated the effect of liver abnormality on the developmental potential of bovine oocytes. Good quality oocytes from healthy cows and from animals with a liver abnormality were matured and fertilized in vitro and then cultured to the blastocyst stage. On day 7 after fertilization, embryo cleavage and development were assessed. The concentrations of glucose, nonesterified fatty acid (NEFA), γ-glutamyl transpeptidase (γ-GTP), β-hydroxybutyrate (BHBA) and glutathione were measured in follicular fluids (FF). The proportion of good quality oocytes and the frequency of development to the blastocyst stage were lower in the liver anomaly group than those of the control group (P<0.05). The concentrations of γ-GTP and BHBA in the FF of the liver anomaly group were higher than those of the control group (P<0.05). The concentration of glutathione in the FF of the liver anomaly group was lower than that of the control group (P<0.05). Moreover, there was a negative correlation between these concentrations and the proportions of oocytes that developed to the blastocyst stage (P<0.05). Supplementation of the culture medium with γ-GTP or BHBA did not affect the rate of oocyte maturation but did cause a concentration-dependent reduction in the frequency of fertilized oocytes that developed to the blastocyst stage. Our findings indicate that the quality of oocytes and their potential for development are lower in cattle with liver disorders than those in healthy cattle; one possible cause may be the high concentration of γ-GTP and/or BHBA in their FF.

Influence of hepatic load from far-off dry period to early postpartum period on the first postpartum ovulation and accompanying subsequent fertility in dairy cows

“…Thus, the present study indicates that the high GGT activity observed in anovulatory cows may not have been caused by fatty liver. However, liver disorders, including hepatitis, degeneration, and telangiectasia, are all more common in cows with fatty livers [ 43 ]. Therefore, anovulatory cows with higher GGT activity may be more likely to acquire such disorders.…”

“…In the present study, ovulation by 3 weeks postpartum was associated with high fertility, supporting the results of previous work [ 2 , 3 , 4 ]. Moreover, cows with liver disorders exhibited higher GGT activity in follicular fluid, as well as a negative correlation between the GGT activity of the follicular fluid and the rate of blastocyst formation after in vitro fertilization [ 43 ]. Sarentonglaga et al .…”

“…Sarentonglaga et al . [ 43 ] concluded that higher GGT activity in follicular fluid causes a reduced glutathione concentration in oocytes and embryos, which results in a decrease in the anti-oxidative capability of the resultant embryos. Thus, oocytes from cows with damaged livers exhibit reduced ability to reach the blastocyst stage [ 46 ].…”

Liver condition of Holstein cows affects mitochondrial function and fertilization ability of oocytes

“…Nearly all ATP is generated in the mitochondria in oocytes [ 29 ], and ATP content in oocytes is higher during the MII stage than the GV stage, indicating that high ATP content is a prerequisite for successful oocyte maturation [ 10 , 18 , 30 ]. In the present study, we compared mitochondrial function by measuring ATP content and membrane potential between the two liver conditions.…”

“…Although the relationship between the negative energy condition and infertility has been reported previously [ 2 , 6 ], few studies have examined the relationship between liver damage and the low quality of bovine oocytes [ 7 , 8 , 9 , 10 ]. In these studies, one of the prominent features of oocytes derived from cows with liver damage was the high frequency of abnormal fertilization [ 8 ]; however, the molecular mechanism underlying fertilization abnormalities are unclear.…”