Estimation of endogenous levels of osteopontin, total antioxidant capacity and malondialdehyde in seminal plasma: Application for fertility assessment in buffalo (Bubalus bubalis) bulls

Content This study was attempted to identify subfertile bulls by quantifying the endogenous levels of osteopontin (OPN), total antioxidant capacity (TAC) and malondialdehyde (MDA) in seminal plasma of buffalo bulls. On the basis of conception rate, buffalo bulls were classified into two groups: high-fertile (conception rate >50%) and subfertile bulls (conception rate <40%). A total of 100 ejaculates (10 ejaculates from each bull) were collected through artificial vagina method. The concentration of OPN, TAC and catalase (CAT) of high-fertile bulls was found to be higher (p<.05) than that of subfertile bulls. Further, MDA level in seminal plasma was found to be lower (p<.05) in high-fertile bulls compared with subfertile bulls. The fertility status had no effect on the superoxide dismutase (SOD) concentration in seminal plasma of both the groups. The levels of OPN (r=.678, p=0.013) and TAC (r=.648, p=.042) were found to be positively correlated with bull fertility and the level of MDA (r=-.718, p=.019) was found to be negatively correlated with bull fertility. However, the fertility of bulls was not found to be significantly correlated with SOD, CAT and sperm motility. In conclusion, seminal OPN, TAC and MDA tended to be more realistic in identification of subfertile bulls from breeding herds.