Correlations among oocyte quality, hepatic triacylglycerols, and some blood metabolites in Carora breed cows during early postpartum

The aim of this study was to assess the relationships of hepatic triacylglycerol (TAG), plasma glucose, plasma cholesterol, and plasma urea nitrogen (PUN) concentrations with the morphological quality of oocytes obtained from 20 Carora breed lactating cows at days 20 and 35 postpartum in a commercial farm. Oocytes were obtained through the technique of transvaginal ultrasound-guided follicle aspiration. Change in body condition score (0.35 vs. 0.44, P = 0.02) and mean plasma cholesterol (3.59 vs. 4.35 mmol/L, P = 0.01) significantly differed between the 2 periods, whereas mean TAG tended to be higher at day 35 after calving (2.29 vs. 2.54%, fresh basis, P = 0.06) and indicated moderately fatty liver. At day 35 postpartum, both plasma cholesterol and TAG tended to have a positive correlation with oocyte quality (%), at r = 0.44 (P = 0.08) and 0.40 (P = 0.05), respectively, but no associations between glucose or PUN and oocyte recovery traits were found at any time. The percentage of oocytes with high quality was found higher (86.7 vs. 52%, P = 0.04) in those cows with more than 4 oocytes recovered. In conclusion, there was a positive relationship among hepatic TAG, plasma cholesterol, and quality of oocytes in Carora breed lactating cows.