Association of light intensity with semen parameters in Duroc boars/Vliv intensity svetla na parametry spermatu kancu plemene duroc

This study aimed to investigate whether the intensity of lighting may affect Duroc boars' semen parameters in different seasons and in different periods from the beginning of the use of boars for semen collection. A total of 6879 ejaculates were collected from 21 boars and kept under natural low light intensity and daylight length conditions, and 3141 ejaculates from 10 boars were kept under high light intensity (190-2101x) and natural daylight length conditions. Experimental groups were divided according to the intensity of lighting (low, high), season (winter, spring, summer, fall), and the period from the beginning of the use of boars for semen collection (0-1 year, 1.1-2 years, 2.1-3 years). Selected parameters were analyzed: semen volume, sperm concentration, total number of sperms, sperm motility, percentage of sperms with an abnormal morphology and number of insemination doses from one ejaculate. Semen volume, sperm concentration, and rate of sperms with an abnormal morphology were associated with the two-way interaction between light intensity and season (P < 0.0001), and between light intensity and period from the first semen collection (P < 0.0001). The total number of sperms and number of insemination doses from one ejaculate were associated with the two-way interaction between light intensity and season (P < 0.0001). Sperm motility was associated with the twoway interaction between light intensity and season (P < 0.0001), and between light intensity and period from the first semen collection (P < 0.01). In conclusion, the intensity of lighting can affect Duroc boars' semen parameters in different seasons and different periods from the beginning of the use of boars for semen collection. Keywords: boar, light, season, semen volume, sperm concentration, total number of sperms, sperm motility, abnormal sperm Cílem práce bylo zjistit, zda intenzita osvetlení, rocní období a doba od zarazení kancu do skupiny pro odber spermatu muze ovlivnit parametry spermatu kancu plemene duroc. Celkem bylo odebráno 6879 ejakulátu od 21 kancu, kterí byli chováni v podmínkách prirozené nízké intenzity osvetlení a délky denního svetla a 3141 ejakulátu od 10 kancu, kterí byli chováni v podmínkách vysoké intenzity svetla (190-210 lx) a prirozené délky denního svetla. Experimentální skupiny byly rozdeleny podle: intenzity osvetlení (nízká, vysoká), rocního období (zima, jaro, léto, podzim) a období, od zacátku pouzívání kancu k odberu spermatu (0-1 rok, 1,1-2 roky, 2,1-3