Abstract
Four hundred fifty-one oocytes were recovered from 115 Holstein cows with ovarian cyst(s) and 159 oocytes were recovered from 36 noncystic normal Holstein cows, respectively. The oocytes recovered from cystic cows were classified as healthy or degenerative by cumulus investment and by nucleus configuration, as well. The relative growth relating follicle diameter to the oocyte diameter in each classification was examined by using regression models. The best fitting models in each group were the hyperbolic regressions with R2 values of 0.994 to 0.999. The growth rates of the oocyte calculated from the differentiated equations of the hyperbolic equations were found to be an asymptotic depression into zero less than 0.5 μm since the follicle grew more than 6.0 mm in diameter. The linear regressions for the growth of the follicle more than 6.01 mm in diameter in relation to that of the oocyte in each abovementioned group all indicated that the true slopes (β)=0 lay somewhere in the 95% confidence intervals of these regressions by the statistical analyses. These results corroborated that the oocytes did not grow but the follicles grew more than 6.0 mm in diameter in both normal and cystic cows. There was no difference between the growth patterns in cystic cows from which healthy and degenerative oocytes were recovered. This was regardless of the judgment by either cumulus investment or nucleus configuration.
