Ejaculate properties and reproductive efficiency of large White boars during exploitation

Abstract

The main objective of this study was to assess the variability of ejaculate properties: volume of ejaculate (VOL, ml), sperm concentration (CON, spermatozoa/ml), total sperm count (NT) and the number of doses produced (NPD) per ejaculate under the influence of season, boar and the interval between two mounts. Reproductive efficiency of boars was analysed based on the farrowing rate (FR). The study included 341 ejaculates from seven Large White boars. Impact assessment was carried out by applying the GLM procedure of the statistical package SAS 9.1.3. The average values of VOL, CON, NT, NPD and FR were: 244.28 ml, 203.77x106 spermatozoa/ml, 43.48x109 spermatozoa, 17.39 doses and 67.58%. Ejaculate properties varied under the influence of season (P<0.01, P<0.001). The interval between two mounts did not affect only the variability of CON. The difference between the best and worst boars was 91.99x106 spermatozoa/ml of ejaculate (P<0.001). During summer VOL ejaculate was the lowest (191.36 ml). The highest NPD (19.04 doses) was produced during the autumn months, and during the same period the highest concentration of sperm was recorded (242.16x106 spermatozoa/ml). Regardless of the differences in the farrowing rate between boars not being statistically significant (P=0.0882), it is necessary to perform the ranking and promptly identify boars with farrowing rate below average.

Keywords

• boar
• ejaculate
• farrowing rate
• rank
• season