HZ-A-018

Although, myriads of tests are routinely used, no single test can accurately predict fertilization potential of semen. The hemizona assay (HZA) has advantages in two ways: (a) it determines multitude traits of sperm and (b) it is a controlled sperm function test. In the present study, we developed homologous HZA in buffaloes to predict bull fertility. In this experiment, bulls with fertility rate 53.3% and 48.5% were used as control, whereas bulls with fertility rate 32.6% and 32.2% were used as test semen samples. For HZA, matching buffalo hemizonae were co‐incubated with processed buffalo sperm for 4 h. The number of sperms bound to the outer surface of hemizona was determined. No significant difference was observed in sperm binding for co‐incubation of same bull sperm with matching hemizona (p < .05). Significant difference in sperm binding to matching hemizona was seen, while two halves were incubated with control and test semen, respectively (p < .05). Hemizona assay index (HZAI) of test bull semen has been determined from percentage of test‐sperm bound to the matching hemizona in comparison to control‐sperm. For finding relation, HZAI was correlated with respective fertility rates of semen samples, and it was found that a significant positive correlation was present with r = 0.83, p < .1. A regression equation of Y = 1.39X − 55.8 (where Y = pregnancy rate of test semen sample and X = HZAI of test semen sample) was presented to predict fertility rates of unknown semen samples. Thus, HZA can be used as a potential predictor of buffalo bull fertility.

The limited predictive value of semen analysis in achieving natural conception or in IVF outcome confirms the need for sperm function tests to determine optimal management. We reviewed HZA and SPA predictive power in IVF outcome, with statistical significance of diagnostic power of the assays. HZA was readily efficient in predicting IVF outcome, while evident inconsistency among the studies analysed framed the SPA’s role in male fertility evaluation. Considerable variation was noted in the diagnostic accuracy values of SPA with wide sensitivity (52–100%), specificity (0–100%), and PPV (18–100%) and NPV (0–100%) together with fluctuation and notable differentiation in methodology and cutoff values employed by each group. HZA methodology was overall consistent with minor variation in cutoff values and oocyte source, while data analysis reported strong correlation between HZA results with IVF outcome, high sensitivity (75–100%), good specificity (57–100%), and high PPV (79–100%) and NPV (68–100%). HZA correlated well with IVF outcome and demonstrated better sensitivity/specificity and positive/negative predictive power. Males with normal or slightly abnormal semen profiles could benefit by this intervention and could be evaluated prior to referral to assisted reproduction. HZA should be used in a sequential fashion with semen analysis and potentially other bioassays in an IVF setting.