Osobine ejakulata i reproduktivna efikasnost nerasta velikog jorkšira tokom iskorišćavanja

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 lt 0.01, P lt 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 lt 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.Osnovni cilj istraživanja bio je da se oceni varijabilnost osobina ejakulata: volumen ejakulata(VOL, ml), koncentracija sperme (CON, spermatozoida/ml), ukupan broj spermatozoida (NT) i broj proizvedenih doza (NPD) po ejakulatu pod uticajem nerasta, sezone i intervala izmedju dva skoka. Reproduktivna efikasnost nerasta analizirana je na osnovu procenta prašenja (FR). Istraživanjem je bio obuhvaćen 341 ejakulat sedam nerasta velikog jorkšira. Ocena uticaja je izvršena primenom GLM procedure u statističkom paketu SAS 9.1.3. Prosečne vrednosti VOL, CON, NT, NPD i FR bile su: 244,28 ml, 203,77x106 spermatozoida/ml, 43,48x109 spermatozoida, 17,39 doza i 67,58%. Osobine ejakulata varirale su pod uticajem sezone (P lt 0,01; P lt 0,001). Interval između dva skoka nije uticao jedino na varijabilnost CON. Razlika izmedju najboljeg i najlošijeg nerasta bila je 91,99x106 spermatozoida/ml ejakulata (P lt 0,001). Tokom letnjih meseci VOL ejakulata bio je najmanji (191,36 ml). Najveći NPD (19,04 doza) proizveden je tokom jesenjih meseci, a tokom istog perioda bila je i najveća koncentracija sperme (242,16x106 spermatozoida/ml). Bez obzira što razlike u procentu prašenja između nerasta nisu bile statistički značajne (P=0,0882), potrebno je vršiti rangiranje i pravovremeno identifikovati neraste sa procentom prašenja ispod proseka