نتایج جستجو برای: bull sperm
تعداد نتایج: 43630 فیلتر نتایج به سال:
An objective method for measuring bovine sperm nuclear shape was developed. Digital images of bovine sperm stained with propidium iodide were collected and Fourier functions used to describe the perimeters of individual sperm nuclei. Harmonic amplitudes from Fourier functions were first shown to be independent of sperm orientation during digitization. Sperm from 12 different bulls were used, an...
Introduction This study evaluated whether post in vitro capacitation changes sperm could be used to estimate field fertility differences between bulls. Methods Frozen-thawed semen from five bulls (two four ejaculates per bull) previously identified as high (48.1% and 47.7%), intermediary (45.5%) or low (40.7% 43.1%) fertility, based on pregnancy AI (P/AI), were for total progressive motility, p...
Experiments were performed on 75 ejaculates obtained from 19 bulls representing different cattle breeds used at the Masovian Centre for Animal Breeding and Reproduction in Łowicz. Fresh ejaculates were measured in respect to their volume and sperm count in the ejaculates was determined. The ejaculates were classified based on the criterion of sperm concentration and divided into five groups. Sp...
Semen production data from an Austrian AI centre collected between 2000 and 2004 were analysed. In total, 12,746 ejaculates from 301 AI bulls were examined considering different effects on ejaculate volume, sperm concentration, percentage of viable spermatozoa in the ejaculate, total spermatozoa per ejaculate and motility. The model included the fixed effects of age of bull, collection interval...
In experiments designed to determine the thermal stability and bonding strength of a natural nucleoprotein structure, the loss of birefringence as a function of time and temperature was investigated for both mammalian and nonmammalian sperm nuclei. At a constant temperature, this reaction was found to be first order for both types over a range of temperatures. The methods of chemical kinetics a...
The present study was designed to compare fertilization rates following oocyte exposure to spermatozoa from different buffalo bulls, using three sperm preparation methods i.e. percoll density gradient, swim-up (modified Ca free Tyrode’s medium and TALP medium) and sodium citrate washing prior to co-incubation with oocytes. Buffalo oocytes were aspirated from ovarian follicles within 1.5 to 2 ho...
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