author(s)
Palanisammi A, V Rajaram, S Rangasamy, SN Sivaselvam and K Kumanan

abstract
The present study involves exploring the utility of osteopontin as a fertility biomarker and also to study its influence on in vitro fertilization. In this study, semen from six Jersey crossbred bulls were collected and sperm parameters like motility, viability, abnormality, plasma membrane integrity, acrosomal integrity, sperm chromatin structure assay and oxidative stress were studied by flow cytometry. There was a significant difference (P<0.01) between the bulls in expression of osteopontin. These results were seen in in vitro fertilization competency determined by the cleavage rate. Pearson coefficient of correlation for the osteopontin expression with the cleavage rate was found to be 0.97 indicating a very high correlation. A bull performance score (BPS) was calculated for the results obtained with the various parameters such as sperm abnormality, viability, HOST, acrosomal integrity, inverse of DFI, inverse of ROS and osteopontin expression. Coefficient of correlation for the BPS with the cleavage rate was high(r=0.969). These results indicated that osteopontin can be used as a fertility biomarker and can also serve as a potential tool for screening the semen quality by flow cytometry before insemination.