Cryopreservation of local black rabbit spermatozoa in the Mekong delta region of Vietnam: Evaluating cryoprotectant effectiveness.

Rabbit production is well developed in the Mekong Delta and Vietnam, with increased consumption of rabbit meat in both urban and rural areas. Consequently, meat rabbit breeds have become popular in almost all provinces in Vietnam, resulting in a decline in the population of Local Black rabbits over the years. To support breeding programs, there is a crucial need to develop a cryopreservation method. The objective of this study was to develop sperm cryopreservation protocols and determine the optimal cryoprotectant for Local Black rabbit spermatozoa. Rabbit spermatozoa were obtained and diluted with TCG-EggYolk freezing medium containing 5%, 8%, and 10% glycerol or DMSO in a 1:1 ratio. Glycerol and DMSO-free mediums served as the controls. Samples were put into 0.5-mL straws, cooled to 15°C and 5°C, then placed on nitrogen vapour for 15 min and directly immersed in liquid nitrogen at -196°C. Samples were thawed at 37°C for 60 s after being frozen for 72 h Sperm quality measures, such as viability, motility, and membrane integrity, were assessed both before and after freezing. The results showed that the average viability, average motility, and average membrane integrity were 61.9%, 53.9%, and 42.9%, respectively, after thawing with 5% glycerol, which was higher than the two higher concentrations of glycerol (8% and 10%) (p < .05). Similarly, with 8% DMSO, the average viability, average motility, and membrane integrity were 59.2%, 51.0%, and 41.8%, respectively, which were higher than the two concentrations of DMSO (5% and 10%) (p < 0.05). Therefore, the cryopreservation of local black rabbit sperm with 5% glycerol or DMSO 8% resulted in high sperm quality, but considering the practical aspect of minimizing the volume of the preservative, a concentration of 5% glycerol may be the best option.

A Study of the Medicinal Plants of Genus Orthosiphon sp.: Aiming to Expand Valuable Medicinal Resources for Medical Treatment.

<b>Background and Objective:</b> <i>Orthosiphon</i> sp., contains many active ingredients that are beneficial to health. In addition to prevention, they are also used in treatment. This study aims to evaluate the agronomic characteristics of 9 <i>Orthosiphon</i> sp., based on morphology and combine molecular biology methods to determine the genetic relationship based on the "ITS1-4" gene region. <b>Materials and Methods:</b> Nine seed samples/species <i>Orthosiphon</i> sp., grown in 9 provinces in South Vietnam were collected and planted for survey at the Can Tho experimental farm. The method of observing and describing the external morphology and microdissection of the eye cage is carried out. The DNA extraction was performed at the Molecular Biology Laboratory, Institute of Food and Biotechnology, Can Tho University. <b>Results:</b> There are differences in some parameters except leaf width and flower diameter. A simple pedigree chart can classify nine cat breeds into 3 groups: Group I includes An Giang (Râ1), Ca Mau (Râ2) and Can Tho (Râ3) breeds that are genetically close to each other and have only the same quantity, group II includes 2 varieties of Vinh Long (Râ8) and Dong Thap (Râ6), group III includes 4 identical samples in Kien Giang (Râ7), Hau Giang (Râ4), Soc Trang (Râ5) and Tien Giang (Râ9). <b>Conclusion:</b> With molecular biology techniques, 9 cat breeds have been identified, all belonging to the species <i>Orthosiphon aristatus</i>. However, to have more accurate and complete conclusions, it is necessary to study some specific gene sequences related to the morphology and substances contained in the plant.