Buscar
Mostrando ítems 1-10 de 1189
Chemotactic selection of frozen-thawed stallion sperm improves sperm quality and heterologous binding to oocytes
(Elsevier Science, 2020-10)
The successful use of assisted reproduction techniques (ART) depends in part on the sperm physiological status. Several sperm selection procedures have been applied to improve quality of sperm population when using the ...
Current sperm competition determines sperm allocation in a Tephritid Fruit Fly
(Wiley Blackwell Publishing, Inc, 2015-05)
Sperm competition (SC) occurs when the sperm of two or more males compete for the same set of ova. Theoretical models and experimental observations indicate that the presence of rival males causes focal males to adjust ...
Evaluation of different doses of mashua (Tropaeolum tuberosum) on the reduction of sperm production, motility and morphology in adult male rats.
(Wiley, 2012)
Mashua is an edible-tuber crop that grows in the Andean region. Folk medicine describes the use of mashua to reduce reproductive function in men. The present study aimed: (i) to determine whether different doses of mashua ...
Intra-male sperm variability: Is there heteromorphism in scorpions (Arachnida, Scorpiones)?
(Elsevier Gmbh, 2016-03)
There is a natural range of variation in sperm morphology inside males. This variation may be adaptive or a result of poor quality control of sperm production. Sperm aggregates can also show different morphologies inside ...
The oviductal sperm reservoir in domestic mammals
(Facultad de Ciencias Veterinarias, Universidad Austral de Chile, 2005)
From storage to delivery: Sperm volume and number of spermatozoa inside storage organs and ejaculates in males of Timogenes elegans (Scorpiones: Bothriuridae)
(American Arachnological Society, 2018-08)
Sperm competition influences the evolution of many reproductive traits such as gonads, sperm or genitalia. Many sperm competition analyses concentrate in testes and ejaculates. Among arachnids, scorpions constitute an ...
Sperm motility in ocellate river stingrays: evidence for post-testicular sperm maturation and capacitation in Chondrichthyes
(Wiley-Blackwell, 2019-01-01)
Sperm maturation, as a process through which spermatozoa acquire the ability for motility activation and fertilization, is well-known for many groups of animals. This process takes place in a taxon-specific manner in ...
Angus sire field fertility and in vitro sperm characteristics following use of different sperm insemination doses in Brazilian beef cattle
(2020-04-15)
The primary objective was to determine if Angus bull fertility varied by number of sperm inseminated. A secondary objective was to characterize the potential impact of random variation on fertility using two identical sperm ...
Organic selenium increases PHGPx, but does not affect quality sperm in raw boar semen
(ElsevierAmsterdã, 2014-06)
This study assessed the effects of feeding organic selenium (Se) on sperm morphology, motility, membrane integrity and lipidic peroxidation, also on sperm ATP and phospholipid hydroperoxide glutathione peroxidase (PHGPx) ...
Decrease in sperm number after treatment of rats with Austroplenckia populnea
(Elsevier B.V., 2000-07-01)
The purpose of this study was to evaluate the effects of a hexanic extract (HE) made from leaves of A. populnea collected in Botucatu, State of São Paulo, and Nova Lima, State of Minas Gerais, Brazil, at a range of doses ...