Role of non-genetic factors on semen production performance in Murrah buffalo bulls

The present study aims to determine the effect of non-genetic factors on semen production traits of Murrah buffalo bulls maintained in an organized semen station. The data collected from 75 Murrah bulls maintained during the period 1997 to 2016 were used to analyse the non-genetic effects using least-squares analysis of variance under General Linear Model (GLM). The overall least-squares means for age at first semen collection (AFSC), age at first semen freezing (AFSF), age at last semen collection (ALSC), age at last semen freezing (ALSF), semen production period (SPP), frozen semen production period (FSPP), age at disposal (AD), number of ejaculates per bull per year, lifetime ejaculates per bull, frozen semen doses per bull per year and lifetime production of frozen semen doses per bull were 1149.71 days, 1160.67 days, 2745.32 days, 2728.73 days, 1313.97 days, 1292.23 days, 2819.09 days, 63.57, 637.88, 5738.60 doses and 69778.32 doses, respectively. Poor semen quality, old age, and poor libido were the predominant causes of disposal of bulls with 42.11%, 22.81%, and 12.28%, respectively. The period of birth of the bulls had a highly significant (p<0.01) effect on AFSC and AFSF and a significant (p<0.05) impact on AD. While the season of birth was not significant for any of the parameters studied. Period I (1997-99) recorded the highest values for AFSC, AFSF, and AD, whereas bulls born in period V (2009-10) exhibited lower AFSC and AFSF. These findings suggest that early selection and training of bulls under preferable managemental conditions will increase the semen production period and frozen semen doses.