The objectives of this study were to determine and evaluate the eff ect of bull, diluter and addition of LDL in diff erent concentration on the percentage rate of spermatozoa survival a er cold shock. In total, four bulls were collected during a period of eight weeks. A total of 8 samples of fresh semen with required quality were processed. Three extenders were used for dilution of each sample; AndroMed®, Bioxcell® and Triladyl®, each in standard and LDL enriched variants. In the case of AndroMed® and Bioxcell®, 4, 6 and 8% of LDL were simply added. In Triladyl®, 6, 8 and 10% of LDL replaced the standard egg yolk component. Resistance of spermatozoa against cold shock (0 °C, 10 minutes) was evaluated by the percentage rate of live sperm using Eosin-Nigrosine staining immediately and 2 hours a er heat incubation (37 °C). The results showed the infl uence of bull individuality as an important factor. Among diluters used it is possible to recommend AndroMed® and Bioxcell® due to signifi cantly (P < 0.01) lower decline of live sperm proportion during the cold shock test than Triladyl® (−9.19, respectively −4.95%). The optimal LDL concentration increasing resistance of spermatozoa against cold shock was not determined, therefore subsequent research is necessary. bull semen, sperm survival, cold shock, extender, LDL cholesterol

The aim of work was to determine the effect of LDL cholesterol addition into selected diluters on the resistance of spermatozoa against cold shock and on their short-term survivability during cold test. The hypothesis was that the addition of LDL cholesterol will positively affects sperm resistance to cold shock and ensures a higher survivability of spermatozoa during short-term cold survival test. Four bulls of different breeds and ages, from the same sire insemination center were used. A total of eight semen collections were processed. Each ejaculate was divided into 6 portions (3 controls and 3 samples). Three commercially produced diluters, AndroMed®, Bioxcell®, and Triladyl® were used, each in standard and LDL enriched variants. In the case of AndroMed® or Bioxcell®, 6% of LDL was simply added. In Triladyl®, 10% of LDL replaced the standard egg yolk component. Spermatozoa resistance to cold shock was evaluated by the percentage of live sperm using Eosin-Nigrosine staining. The results showed the influence of bull individuality as an important factor. It is possible to recommend Bioxcell® with addition of LDL cholesterol in 6% concentration, which survivability was 69.17% at the beginning of the test, and 52.94% after 2 hours of incubation.

Krejcárková A., Folková P., Šimoník O., Šašková M., Krejčířová R., Drábek O., Rajmon R. (2017): Effects of zearalenone, α-zearalenol, and genistein on boar sperm motility in vitro. Czech J. Anim. Sci., 62, 435-445.Genistein (GEN) and zearalenone (ZEA), environmental oestrogens commonly present in feedstuff for pigs, are known for their effects on reproductive functions. The aim was to verify the in vitro effects of 0.5-20 µM concentrations of GEN, ZEA and its metabolite α-zearalenol (α-ZOL) on pig sperm motility. A dose-dependent increase of the immotile sperm amount against fast and medium-fast sperm clusters was observed with all three oestrogens from the lowest concentrations tested. Individual CASA (computer-assisted sperm analysis) parameters of motile sperms seemed to be less sensitive indicators. This should be considered especially in toxicological research on a sperm model. Background of inconsistencies in to date-published papers is discussed. The results shift the effective concentrations of ZEA, α-ZOL, and GEN to values achievable in vivo and raises the questions of risk assessment of these compounds in pig reproduction.

The present review summarizes the findings about the mechanism and the effects of soy phytoestrogens and zearalenone acting. These substances commonly occur in plant feeds for animals. Owing to their estrogenic effects, they can disturb physiological functions in organism, mainly in the area of reproduction. Consequently, the negative impact of these substances is reflected in the overall economy of the livestock breeding.