Učit se znamená objevovat to, co už víš.
Konat znamená demonstrovat, že to to víš.
Učit druhé znamená připomínat jim, že to vědí stejně dobře jako ty.
Všichni jste zároveň žáci, praktikanti a učitelé.
Richard Bach
The quality of ejaculate varies significantly during the season. The highest fluctuations are observed in all species of male livestock in the summer months at higher temperatures (Pinart et al. 2013). Also stress itself may influence the body temperature (Jancikova et al. 2012b, Vinkers et al. 2013).
Quality of ejaculate of boars decreases at increased heat load. A reduction of motility and concentration of sperms as well as an increase of percentage of abnormal sperm have been recorded (Martin-Hidalgo et al. 2013). Reduced sperm motility is caused by a lower level of ATP (Nevrkla et al. 2012, Gogol 2013, Nevrkla et al. 2013). In the boars, the quality of ejaculate is largely influenced by season. The best quality of ejaculate is observed in spring and autumn. Conversely, in the summer, when the animals are exposed to high temperatures, significantly worse qualitative and quantitative indicators of the ejaculate are recorded. An influence of breed has also been recorded (Tretipskul et al. 2012, Horky 2014). High temperature may also cause an excessive loading the organism with oxygen radicals and decrease in activity of antioxidant enzymes (dos Santos et al. 2013). In some cases, overproduction of free radicals causes a damage of biomolecules and cancer (Vyslouzilova et al. 2013) (Pohanka et al. 2013). Reactive oxygen species (Belakova et al. 2014) negatively affect the quality of sperms. Negative impact of these reactive oxygen species causes peroxidation of lipids that create the outer shell of sperms (Ashrafi et al. 2013). Reactive oxygen species may affect the metabolism of proteins in the ejaculate (Hadaš et al. 2012, Sharma et al. 2013). High temperature also affects the reproductive performance of breeding pigs (Prunier et al. 1997, Horky et al. 2012b).
The aim of this experiment was to evaluate an effect of heat stress on biochemical parameters of ejaculate of breeding boars in terms of changes in antioxidant status. The operational objective was to evaluate the effect of the thermal stress on the qualitative parameters of produced ejaculate.
32— 2014
31— 2014
30— 2014
29— 2014
28— 2014
27— 2014
26— 2014
25— 2014
24— 2014
23— 2014
22— 2014
21— 2014
20— 2014
19— 2014
18— 2014
17— 2014
16— 2014
15— 2014
14— 2014
13— 2014
12— 2014
11— 2014
10— 2014
9— 2014
8— 2014
7— 2014
6— 2014
5— 2014
4— 2014
3— 2014
2— 2014
1— 2014
42— 2013
41— 2013
40— 2013
39— 2013
38— 2013
37— 2013
36— 2013
35— 2013
34— 2013
33— 2013
32— 2013
31— 2013
30— 2013
29— 2013
28— 2013
27— 2013
26— 2013
25— 2013
24— 2013
23— 2013
22— 2013
21— 2013
20— 2013
19— 2013
18— 2013
17— 2013
16— 2013
15— 2013
14— 2013
![]() | Zemědělská 1/1665 613 00 Brno Budova D | Tel.: +420 545 133 350 Fax.: +420 545 212 044 | ![]() |
![]() |