Showing papers by "University of Veterinary Science published in 2005"

A review of the genera Myotis, Ia, Pipistrellus, Hypsugo, and Arielulus (Chiroptera: Vespertilionidae) from Myanmar (Burma), including three species new to the country

Abstract: Since 1999, the University of Yangon and the Harrison Institute have conducted a series of bat surveys in Myanmar. During this time, six species of vespertilionid bat have been collected that have not been recorded previously from the country. Two, Myotis horsfieldi and Myotis chinensis were published in 2001 and one, Kerivoula kachinensis, which is a new species to science, in 2004. The remaining three, Myotis mystacinus, Ia io and Pipistrellus pulveratus are included here for the first time. The record of M. mystacinus is the first authenticated one for South-East Asia. Since small vespertilionid bats are difficult to identify and are generally poorly understood, the paper includes a brief review of all 24 species of Myotis, Ia, Pipistrellus, Hypsugo, and Arielulus currently listed for Myanmar. Three of these, Myotis annectans, Pipistrellus pipistrellus and Hypsugo savii are removed from the faunal list for lack of supporting data or because of previous misidentifications. The taxon Pipistrellu...

Antibiotic Resistance and Plasmid Carriage among Escherichia Coli Isolates From Chicken Meat in Malaysia

Abstract: Escherichia coli isolates from 131 raw chicken meat samples were tested for susceptibility to 12 antibiotics. Plasmids were isolated from many samples and their DNA molecular weight calculated. An 81.7% plasmid occurrence rate was observed among the isolates, ranging from 0 to 8 in number and with sizes from 1.2 to 118.6 MDa. Plasmids were detected in 93.8% of E. coli isolates resistant to all 12 antibiotics, and in 90.5% of E. coli isolates resistant to 11. Three (2.8%) isolates harboured 8 plasmids and were resistant to all 12 antibiotics. Antibiotic resistant genes in bacteria are usually carried in extrachromosomal DNA and it is postulated that E. coli with a high number of plasmids possesses wider resistance to antibiotics.

Effect of clenbuterol on the clearance of particles of charcoal (4 to 90 μm) from the uteri of mares

Abstract: The failure of clearance mechanisms in the mare’s uterus results in persistent inflammation and is considered a major cause of subfertility. Eighteen mares, of which three were susceptible to endometritis and four had been ovariectomised, underwent charcoal clearance testing to evaluate their clearance mechanisms. This consisted of installing 500 mg of charcoal (particle size 4 to 90 μm) added to 50 ml of phosphate-buffered saline (PBS) into the uterus. Forty-eight hours later the uterus was flushed out with 0·0012 per cent methylene blue in 50 ml of PBS for determination of the diluting factor by photospectrometry. Flush volume, pH, specific gravity and pellet size were all analysed. To investigate the effect of a β2-adrenergic agonist on the ability of genitally healthy oestrous mares to eliminate a suspension of charcoal from the uterus, four genitally healthy mares with appropriate charcoal clearance were also subjected to clearance testing following intravenous administration of 0·8 μg/kg of clenbuterol every 12 hours and 1 μg/kg of clenbuterol every eight hours. All parameters were within their normal range following clenbuterol treatment. However, minimal but significant differences in pre- and post-treatment values regarding fluid volume and extinction rate were recorded.

98 the effect of high hydrostatic pressure on the motility of fresh and frozen-thawed bull semen

Abstract: Previously, we reported that a sublethal shock, high hydrostatic pressure (HHP), significantly improves the post-thaw survival of frozen mouse blastocysts, presumably from the induction of shock proteins (Pribenszky et al. 2004 Reprod. Fert. Dev. 16, 181). Others reported that HSP90 in spermatozoa decreased substantially after freezing (Huang et al. Theriogenology 51, 1007–1016; Cao Wen-Lei et al. 2003 Asian J. Androl. 5, 43–46). We now report the effect of HHP on motility of the fresh bull semen to determine whether sperm survives in an altered pressure environment, and to compare post-thaw motility of HHP-treated frozen bull semen with controls. The survival rates were compared by chi-square test. Expt 1: Semen of one bull was diluted to a sperm concentration of 8 × 107/mL with AndroMed extender (MiniTub, Tiefenbach, Germany). Diluted sperm was loaded into 0.25-mL straws at 25°C. Each straw was cut in half. One demi-straw was heat-sealed and exposed to HHP, and sperm in the companion demi-straw served as a control. Experiments were replicated eight times for each pressure/time treatment. Progressive motility was assessed independently by light microscopic investigation by two individuals. The treatment groups were: 10 MPa for 30, 60, 90, or 120 min; 30 MPa for 30, 60, 90, 120, or 510 min; 50 MPa for 30, 60, or 90 min; 70 MPa for 30, 60, or 90 min; and 90 MPa for 30, 60, 90, 120, or 510 min. The average motility of the control samples ranged from 75 to 90%, while the average motility of the pressurized samples ranged between 55 (90 MPa/120 min) to 84% (10 MPa/30 min). The groups of 30 MPa/510 min and 90 MPa/510 min exhibited significantly lower motility compared to the other pressurized groups (27% and 33%, respectively; P < 0.05). Expt 2: Semen was collected from two bulls with poor sperm freezability. Semen was diluted as described for the first experiment, loaded into straws, and assigned to one of 4 treatment groups. Half the straws from each bull were exposed to 90 MPa/30 min, 90 MPa/90 min, 30 MPa/30 min, or 30 MPa/90 min, and then cryopreserved. Controls consisted of straws that were cryopreserved without pressure treatment. Cryopreservation steps were 60 min equilibration at 5°C, followed by 10 min at −110°C, and then plunging into liquid nitrogen. Straws were thawed in a 35°C water-bath for 30 s. Each treatment and control group was replicated 8 times (8 samples per bull). The average post-thaw motility was significantly superior with pressure pre-treatment in each of the pressurized groups compared to the samples frozen without previous pressurization (P < 0.001) (Bull I: 2–3% without pressurization vs. 17–33% with pressurization; Bull II: 0% without pressurization vs. 21–35% with pressure pre-treatment). Among the pressure/time parameters used, 30 MPa/90 min proved significantly superior (33 and 35%; P < 0.05) for each of the bulls. Expt. 2 clearly demonstrates the beneficial effect of a previous pressure treatment on post-thaw motility of bull semen cryopreserved in our experiment. Further investigations are needed, including samples from different bulls, different freezing protocols, and the biological background of the process. This work was supported partly by NKFP 4/040/2001.