Effect of collection technique and stage of estrous cycle on oocyte retrieval in goat (Capra hircus)

The present study was undertaken to assess the relative efficiency of three different collection techniques on average oocyte recovery per ovary, oocyte quality and per cent of different quality oocytes retrieved in local goats. The mean oocyte recovery from right and left ovary was 1.9 ± 0.28 and 0.8 ± 0.18 in aspiration technique, 2.15 ± 0.31 and 2.9 ± 0.46 in dissection technique and 6.55 ± 0.57 and 4.51 ± 0.46 in slicing technique.

The mean oocyte recovery rate was 1.5 ± 0.22 and 1.0 ± 0.33 under aspiration technique, 2.58 ± 0.47 and 2.43 ± 0.36 under dissection technique and 5.26 ± 0.46 and 6.3 ± 0.71 under slicing technique from the ovaries in follicular and luteal phases of estrous cycle in nondescriptive does, respectively significantly (P<0.05) higher number of oocytes compared to luteal phase. The correlation of oocyte recovery in aspiration with length, width, thickness and weight was 0.16, 0.10, 0.19 and 0.11, respectively. Slicing techniques showed a correlation with length (0.25), width (0.43), thickness (0.26), and weight (0.09). The values of correlation coefficient of oocyte recovery in dissection techniques with ovarian biometrics were length (0.01), width (−0.04) thickness (−0.03), weight (−0.003). The mean numbers of oocytes of different grades recovered were 0.34 ± 0.03, 0.62 ± 0.07 and 1.37 ± 0.09 in aspiration, dissection and slicing techniques, respectively. Among the different grades of oocytes, significantly higher per cent of ‘A’ (27.78) and ‘B’ (38.89) grade oocytes were retrieved by aspiration and dissection technique when compared to slicing technique. With respect to ‘C’ and ‘D’ grade oocytes, significantly higher numbers of oocytes were retrieved by slicing technique than the aspiration and dissection techniques. Out of 437 oocytes retrieved in the present study, significantly higher per cent (50.57) yield was by slicing technique, followed by dissection technique (37.07) and aspiration (12.53).