Browsing by Subject "β-karoteeni"

β-carotene is a precursor of vitamin A which regulates the functions of the reproductive system and it is also one of the antioxidants that protect fatty acids in cell membrane from the oxidizing effects of free radicals. Based on previous reports the intake of β-carotene may have a positive effect on sperm quality. The purpose of this study was to research the effect of β-carotene in carrot on the quality parameters of semen of young bulls and to find out, if beta-carotene can improve sperm quality so that the sperm doses which meet quality requirements can be collected earlier. In the experimental setup 38 bulls were divided into pairs. The bulls in the experimental group were given 2 kg of carrots per day since the age of 34 weeks. The vitamin A and the energy intake during the experiment followed feeding recommendations for bulls. The energy content of carrots did not have a significant effect on the energy intake of the bulls in the experimental group. Sperm viability, motility, and sperm density of bull's semen were determined both before and after freezing. Semen below the quality limits were not frozen (sperm density ≤ 500 million sperm cells / ml, viability and motility ≤ 70%). The results were examined from bulls aged 37-52 weeks. Statistical testing was performed by analysis of variance (Mixed procedure in SAS software). The quality of the sperm improved in all the measured quality parameters as the bull grew. There were no differences between feeding groups in sperm density, viability, motility, ejaculate volume, sperm count and proportion of rejected samples before freezing. The first approved sample tended to be earlier in the control group than in the experimental group (307 vs. 324 days, P = 0.07). After freezing the sperm, density in the experimental group was tended to be higher (61.4 vs. 64.1 million sperm / ml, P = 0.07). Sperm viability was higher in the control group (64.4 vs. 57.7%, P = 0.002). There was no difference in sperm motility or daily growth of bulls between the feeding groups. Blood β-carotene concentration was higher (P = 0.002) in the experimental group in the end of the experiment. The testicular circumference was tended to be larger in the control group (p = 0.099). β-carotene increased sperm density, but sperm viability was higher in the control group. β-carotene had no effect on sperm motility. β-carotene did not improve sperm quality in a way that would allow to collect high-quality sperm doses from younger bulls. The age difference of the bulls at the time of first approved sample most likely did not result from β-carotene but from the differences in the onset of puberty.