Publications by authors named "Helder M Souza"

l-Carnitine (LC) plays a key role in sperm metabolism, easily providing energy through β-oxidation, which positively affects motility. The objective of this study was to investigate the association between blood plasma and seminal plasma LC levels, as well as the effect of LC as an additive in a skimmed milk-based extender during sperm storage at 5°C. In the first experiment, semen and blood samples from 14 Quarter Horse stallions were used.

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The objective of this study was to investigate the need of seminal plasma removal for short-term cooling of buck semen in soybean lecithin (SL) based extender. Each pool was divided equally, and one half was subjected to centrifugation to remove seminal plasma (SP-), while the other half remained with seminal plasma (SP+). Then, both SP+ and SP- samples were diluted in two SL extenders (extender A = 1% SL; extender B = 2% SL), cooled to 5ºC and stored for 48 hours.

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The addition of antioxidants to semen cryopreservation extenders has been employed for combating oxidative damage. This work aimed to evaluate the addition of carotenoid canthaxanthin to a cryopreservation extender of ram semen. Three breeder rams were used and, after semen collection, with 48-hour intervals between collection, the samples were included in the pool formation (n = 6).

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