نتایج جستجو برای: bull sperm
تعداد نتایج: 43630 فیلتر نتایج به سال:
Apoptosis is common during spermatogenesis. Here, it was tested whether apoptosis could be induced in sperm after ejaculation. There were several lines of evidence to indicate that sperm are resistant to induction of apoptosis. First, incubation of bull sperm at temperatures characteristic of normothermia (38.5 degrees C) or heat shock (40 and 41 degrees C) for 4h did not increase the proportio...
Computer-assisted sperm analyzers (CASA) have become the standard tool for evaluating sperm motility because they provide objective results for thousands of mammalian spermatozoa. Mammalian spermatozoa experience osmotic stress when the glycerol is added to the cells prior to freezing and removal from the cells after thawing. In order to minimize osmotic damage, cryoprotectants having lower mol...
Background Although artificial insemination (AI) technique is an established biotechnology for bovine reproduction, the results of AI (conception rates) have a tendency to decline gradually. To our annoyance, moreover, AI-subfertile bulls have been occasionally found in the AI centers. To resolve these serious problems, it is necessary to control the sperm quality more strictly by the examinati...
To preserve Jeju black cattle (JBC; endangered native Korean cattle), a pair of cattle, namely a post-death cloned JBC bull and cow, were produced by somatic cell nuclear transfer (SCNT) in a previous study. In the present study, we examined the in vitro fertilization and reproductive potentials of these post-death cloned animals. Sperm motility, in vitro fertilization and developmental capacit...
As an attempt to find an inexpensive and simple laboratory method for artificial insemination (AI) bull semen quality assessment, the osmotic resistance of spermatozoa was measured using the hypoosmotic swelling (HOS) test, developed by Jeyendran et al. (1984) (labelled HOS-1), and its modifications (HOS-2, HOS-3), with decreased osmotic pressure aimed at challenging sperm survival ability. The...
Aim: Present investigation was carried out to study the physical characteristics of Kankrej bulls semen by evaluation of various semen parameters from neat semen and at various stages of semen preservation. Materials and Methods: A total of 60 ejaculates, 10 each from 6 mature Kankrej bulls, once in a week for 10 weeks, were collected and analyzed for various semen attributes. Result: The mean ...
The aim of the present study was to evaluate the effects of different seasons on the morphometric testicular parameters and the respective epididymal sperm parameters. Total numbers of 104 scrota of pubertal buffalo bull (24-48 months) include their contents were provided from the local slaughterhouse. Scrotal circumference was measured on its place before dissection. Morphological parameters o...
The aim of this study was to compare the sperm nuclear and acrosomal morphometry of three species of domestic artiodactyls; cattle (Bos taurus), sheep (Ovis aries), and pigs (Sus scrofa). Semen smears of twenty ejaculates from each species were fixed and labeled with a propidium iodide-Pisum sativum agglutinin (PI/PSA) combination. Digital images of the sperm nucleus, acrosome, and whole sperm ...
background: control of the medium osmolarity and temperature during long or short time sperm manipulation is essential. objective: the objectives of the present study were to find the effects of different osmolarities of modified tyrode's solution and milk on the bull sperm during incubation at above zero temperatures. materials and methods: semen samples were collected twice from five najdi bu...
Damage occurring to spermatozoa during cryopreservation results in a loss of motile cells and cells that are functionally normal, compared with fresh sperm samples. Treating bull sperm with cholesterol-loaded cyclodextrins (CLC) before cryopreservation results in increased sperm cryosurvival. However, in previous studies, CLC were always added to sperm samples that had been highly diluted. The ...
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