The slides were dried using a hot-plate (40 °C) overnight. Then, the slides were immersed into a series of xylenes, dehydrated in a series of ethanol, stained in a haematoxylin solution, decolorized in 1% acid alcohol, re-stained in 0.5% aqueous eosin and lastly, mounted with DPX to prepare a microscope slide. During observations, oocyte diameter was measured and number of oocytes were estimated (Leica Microsystem, Wetzlar GmbH,DMLB 2,Germany).