For centuries, sanchi has been used in traditional medicine in East Asian countries to promote health and fitness. To identify and distinguish sanchi from adulterants, this study was conducted to determine the sequence of four DNA barcodes. The PCR products of the four barcodes were 330 bp (rbcL), 822 bp (matK), 484 bp (trnH-psbA), and 438 bp (ITS1). Genetic relationship analysis showed that the four DNA barcode regions had high similarity with other Panax species. Three barcodes, matK, trnH-psbA, and ITS1, confirmed that the studied samples belonged to Panax notoginseng, distinguished from Panax pseudoginseng, and can be used to identify Panax notoginseng.

This study aimed to determine subclinical mastitis (SCM) caused by bacterial species, using chromogenic culture media and to assess the antimicrobial resistance rate in the isolated bacteria. From March to December 2023, 143 milk samples were collected from 71 Holstein Friesian cows with SCM across seven dairy farms in Ho Chi Minh City and Binh Duong province. Milk samples were incubated in triplicate chromogenic culture media to identify SCM caused by microorganisms. Our study revealed that 39.2% (56/143) of the samples had the growth of a single morphology, 26.6% (38/143) exhibited growth of two distinct morphologies, 9.0% (13/143) were found to be contaminated, and 25.2% (36/143) showed no growth. The isolated Streptococcus species were Strep. agalactiae 34.3% (49/143), Strep. uberis 22.4% (32/143), and Enterococcus spp. 1.4% (2/143). Besides, S. epidermidis 20.3% (29/143), S. saprophyticus 14.7% (21/143), and S. aureus 4.2% (6/143) were frequently isolated among Staphylococcus species. For gram-negative bacteria causing SCM, E. coli 2.8% (4/143), Klebsiella spp. 1.4% (2/143), and Pseudomonas spp. 4.2% (6/143) were the most isolated. Regarding antimicrobial susceptibility testing, the resistance rate of each bacterial species to each antibiotic tested differed for Staphylococcus, Streptococcus, and gram-negative bacteria. Staphylococcus aureus was not resistant to gentamycin, florfenicol, and marbofloxacin. The resistance rate of S. epidermidis to gentamycin, florfenicol, trimethoprim sulfadiazine, and amoxicillin-clavulanic acid varied from 10.3% to 17.2%. Marbofloxacin and trimethoprim-sulfadiazine were excellent choices in treating SCM caused by S. saprophyticus because of their low resistance rate (10.3 - 13.3%). Streptococcus uberis was sensitive to the combined antibiotic amoxicillin-clavulanic acid. The resistance rate of Strep. agalactiae to this combined antibiotic (amoxicillin-clavuclanic acid) was the lowest (10%). Pseudomonas spp. was resistant to the tested antibiotics. Our study suggests that identifying bacterial species and conducting antimicrobial susceptibility tests play a crucial role in improving the treatment effectiveness for bovine SCM.

The research on snail composition and their cercariae by morphological analysis method in Xuan Thoi Thuong rice field of Hoc Mon district, Ho Chi Minh City, Vietnam was carried out in the wet season of August 2022 and the dry season of February 2023. A total of 993 snails were collected and 11 snail species belonging to 9 genera and 5 families were classified. There were 9 snail species collected in the wet season and 7 snail species found in the dry season. Lymnaea viridis and Bithynia siamensis were infected with trematode (cercariae stage) with the combined prevalence of 14.3% and 4.1%, respectively. The other nine snail species had cercariae free. Two cercariae morphotypes were discovered from snails including Xiphidio cercariae and Echinostome cercariae. More research on snails and their cercariae in other waterbodies should be done in Hoc Mon district and other places to identify the snail diversity and sources of trematodes affecting fish culture and human health.

The study was conducted to evaluate the growth performance, survival rate and yield of all male sex reversed and mixed sex Nile tilapia (Oreochromis niloticus) cultured in earthen ponds for 180 days. The reversed sex and mixed sex fingerlings (mean weight 7.43 ± 0.35 g) was randomly stocked in six earthen ponds (1,000 m2/pond). The stocking density maintained was 5 fish/m2. The stocked fish were fed a commercial pellet feed containing 35% crude protein. The feeding rate was adjusted according the size of fish, 5% at the beginning to 3% at harvest. Water environment parameters including dissolved oxygen (DO) (4.3 ± 0.8 mg/L), temperature (30 ± 0.7°C), NH3 (0.18 ± 0.2 mg/L), and pH (6.9 ± 0.5) were always within the appropriate range for the normal growth and development of tilapia. The growth rate of sex reversed tilapia was significantly higher (P < 0.05) than that of mixed tilapia throughout the experiment. The harvest weight and length of reversed sex tilapia were 410.5 ± 5.15 g and 25.48 ± 0.48 cm, respectively, and were significantly higher than that of mixed sex tilapia (P < 0.05). The survival rates and feed conversion ratio (FCR) of mono and mixed sex were 90.1% and 89.9%, respectively, but no significant differences were observed (P > 0.05). The relationship of fish lengths and weights expressed by power function revealed that the slope of the length weight regression lines was normal for reversed sex (2.72) and mixed sex Tilapia (2.93) with the high correlation coefficient (> 0.9). The findings of this study demonstrate that reversed sex tilapia has better growth performance compared to mixed sex tilapia. Therefore, reversed sex fingerlings should be used in commercial farming to increase tilapia production.

Tire track eel (Mastacembelus favus) is an economically important freshwater fish in the Mekong Delta. However, there is a lack of academic information about the current farming status, feed, and feeding related to this species in the region. Therefore, a field survey of small scale farming of tire track eel was conducted in An Giang, Dong Thap, Hau Giang and Kien Giang provinces of Vietnam. The objective of the survey was to determine the current farming practices information on households, especially the feed and feeding status of tire track eel in order to improve and develop a suitable feed for this fish in the future. The results showed that most of the small-scale farmers cultured fish in earthen ponds with or without plastic liners. Tire track eels were fed with feeds of other species and typically fed 3 - 5 times/d during the fingerling stage, and twice per day during the grow-out period. In terms of feed ingredients, crude protein contents in the feeds were 39.5 - 45.5% while crude lipid contents were 7.7 - 12.7%. Feed conversion ratios of tire track eels were 2 - 5. The farming periods of fish were 11.8 - 14 months when the fish reached the harvesting sizes of 318.2 - 421.4 g/fish, with the survival rates of 40 - 80%. It took 2.5 months to cultivate the fingerling stage (around 3 g/fish) from the fry with the survival rate of 55.7%. It was reported that this species was raised with a simple technique and got less illness compared to other fish species. However, the main reason of fish deaths during farming period related to management factors such as poor water quality due to decomposition of uneaten feed in water or lacks of dissolved oxygen due to high stocking density or power supply failures.