Measurements were made of the rigor stiffness of impaled bull sperm flagella. Vanadate-free ATP was found to have a stronger plasticizing action than vanadate-contaminated ATP. Trace amounts of Mg2+ were found to be necessary to relieve the rigor condition by ATP. During the injection of negative electric current into the sperm head, the flagella stiffened, presumably by depletion of Mg2+ from ...

In the present study, bull sperm in the first and second ejaculates were divided into subpopulations based on their motility characteristics using a cluster analysis of data from computer-assisted sperm motility analysis (CASA). Semen samples were collected from 4 Japanese black bulls. Data from 9,228 motile sperm were classified into 4 clusters; 1) very rapid and progressively motile sperm, 2)...

Background Cryopreservation of semen requires optimized conditions to minimize the harmful effects of various stresses. The main approach for protection of sperm against stress is based on the use of antioxidants and cryoprotectants, which are described as defensive methods. Recently, the application of controlled mild stressors has been described for activation of a temporary response in oocyt...

The present study was conducted to determine the correlation of hypo-osmotic swelling test with conventional semen evaluation parameters of fresh semen collected from two Nili-Ravi buffalo and two Sahiwal cow bulls. A total of 10 pooled samples (each comprising two consecutive ejaculates) from each bull were collected. Each semen sample was divided into two parts. One part was used for the eval...

The aim of current study was to investigate the changes in the quality parameters of Holstein bull semen during the heat stress and the effect of feeding a source of omega-3 fatty acids in this period. Samples were obtained from 19 Holstein bulls during the expected time of heat stress in Iran (June to September 2009). Control group (n=10) were fed a standard concentrate feed while treatment gr...

Selection of high-quality sperm is crucial to assisted reproduction. However, conventional clinical methods for selection are manual and prone operator errors. This article presents ‘sperm syringe', a scalable technology that mimics the highly parallelized 3D process in vivo via network 560 microchannels select sperm. Sperm syringe retrieves more than 41% healthy from initial sample under 15 mi...

Dispersion of nuclear fibers of the spermatozoa of dogfish, man, and bull is made possible after treatment with a reducing and alkylating reagent coupled with an anionic detergent; the same detergent used at a low ionic strength dissociates the nuclear content of the rainbow trout sperm. Electron microscopy of such dispersed nuclear fibers has shown a beads-on-a-string configuration for these f...

The Geometric Clutch hypothesis is based on the premise that transverse forces (t-forces) acting on the outer doublets of the eukaryotic axoneme coordinate the action of the dynein motors to produce flagellar and ciliary beating. T-forces result from tension and compression on the outer doublets when a bend is present on the flagellum or cilium. The t-force acts to pry the doublets apart in an ...

Abstract Background The use of sex-sorted sperm in cattle assisted reproduction is constantly increasing. However, fertility can substantially differ between unsorted (conventional) and semen batches the same sire. Sperm microRNAs (miRNA) have been suggested as promising biomarkers bull last years. In this study, we hypothesized that miRNA profile cryopreserved conventional related to after art...

Heparin-binding proteins (HBP) recognized by a monoclonal antibody (M1) are produced by male accessory sex glands and bind to distinct regions of ejaculated bull sperm. Immunoblots of sperm proteins probed with M1 identified HBP variants of approximately 31-, 24-, and 21.5-kDa that were associated with increased fertility of bulls. The purpose of this study was to identify the 31-kDa HBP known ...