Ngày xuất bản: 2024-06-21

Identification of sanchi samples based on DNA barcodes

Phạm Thanh Đông & Nguyễn Vũ Phong
Bản điện tử: 21 Jun 2024 | DOI: 10.52997/jad.3.01.2024
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Tóm tắt

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.

Evaluating the growth performance of all male sex reversal and mixed ser tilapia (Oreochromis niloticus) cultured in earthen ponds in Binh Phuo province, Vietnam

Nguyễn Ngọc Lợi, Nguyễn Hải Đăng, Nguyễn Bảo Nam, Nguyễn Thị Hồng Nhung & Nguyễn Thị Hiền
Bản điện tử: 21 Jun 2024 | DOI: 10.52997/jad.3.04.2024
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Tóm tắt

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.

Investigation of small-scale farming status of Tire track eel (Mastacembelus favus) in the Mekong Delta, Vietnam

Nguyễn Hữu Yến Nhi, Nguyễn Thị Thúy Hằng, Nguyễn Thị Bích Hạnh, Phan Thị Thanh Vân, Trần Đạt Thắng, Hồ Văn Minh Mẫn & Trịnh Thị Lan
Bản điện tử: 21 Jun 2024 | DOI: 10.52997/jad.3.02.2024
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Tóm tắt

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.

Bacterial species causing subclinical mastitis in dairy cows: rapid identification and antimicrobial susceptibility testing

Lý Hồng Sơn, Phạm Thanh Tuấn, Ôn Mai Ngọc Hân, Trương Đình Bảo & Nguyễn Thị Thương
Bản điện tử: 21 Jun 2024 | DOI: 10.52997/jad.3.05.2024
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Tóm tắt

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.

Snail composition and its cercariae in rice field of Hoc Mon district, Ho Chi Minh City, Vietnam

Phạm Cử Thiện & Dương Thị Quyên
Bản điện tử: 21 Jun 2024 | DOI: 10.52997/jad.3.03.2024
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Tóm tắt

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.

Kiểm kê và đề xuất giải pháp cho cây đường phố ở TP. Thủ Đức, TP. Hồ Chí Minh

Dương Thị Mỹ Tiên, Vương Thị Thủy, Ngô Thị Minh Thê & Nguyen Thien Thanh
Bản điện tử: 21 Jun 2024 | DOI: 10.52997/jad.3.06.2024
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Tóm tắt

Kiểm kê cây xanh đóng một vai trò thiết yếu trong quy hoạch tổng thể cảnh quan đô thị. Nó là nền tảng cho việc thu thập dữ liệu hỗ trợ chiến lược quy hoạch và các quyết định liên quan đến lợi ích của cộng đồng, đặc biệt là ở các thành phố mới thành lập như Thành phố Thủ Đức. Nghiên cứu này được thực hiện từ tháng 10 năm 2021 đến tháng 12 năm 2022 tại thành phố này nhằm mục đích kiểm kê để thu thập thông tin đủ điều kiện phục vụ công tác quản lý cây xanh đường phố của thành phố này. Nghiên cứu sử dụng mẫu kiểm kê cây xanh đường phố bao gồm các tiêu chí như tên, họ, đường kính ngang ngực, chiều cao vút ngọn, các chỉ tiêu về sức sống và khoảng cách từ cây đến công trình hạ tầng. Theo đó có 287 con đường đã được khảo sát. Tổng số cây điều tra được là 31.023 cây thuộc 65 loài và 24 họ thực vật, trong đó các loài chiếm tỷ lệ cao là Dầu rái, Sao đen, Lim xẹt và Bằng lăng. Họ thực vật chiếm tỷ lệ nhiều nhất là Fabaceae. Cây đường phố ở đây có chiều cao phổ biến dưới 10 m và đường kính ngang ngực dưới 20 cm. Nhiều đường có khoảng cách giữa cây xanh và hạ tầng không đúng quy định, nhất là khoảng cách đến đường dây điện. Đa số cây xanh phát triển khỏe mạnh và có sức sống tốt. Cần ưu tiên thực hiện ba giải pháp được nêu để cải tạo và phát triển cây xanh đường phố tại Tp. Thủ Đức.

Influence of the supplementation of macadamia oil cake powder on nutritional and sensory qualities of bread

Hoàng Văn Chuyển & Đỗ Long Anh Duy
Bản điện tử: 21 Jun 2024 | DOI: 10.52997/jad.3.08.2024
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Tóm tắt

Although macadamia oil cake (MOC) is a by-product of macadamia oil processing, this material still has high nutritional value, making it a promising ingredient for food products. This study aimed to investigate effects of the MOC supplementation at different ratios on physical properties, nutritional composition and sensory quality of bread. The results show that the addition of MOC led to increases in protein, ash and fat content, while carbohydrate content was lower in the supplemented bread. The specific volume and springiness of the bread were significantly affected by the MOC supplementation while no significant change in hardness and spread ratio was observed (P < 0.05). For the sensory quality of fortified bread, the differences in color, flavor, texture and overall acceptability among 4 levels of MOC addition were insignificant, except for the taste score. Microbiological analyses also confirmed that the MOC supplemented bread product met microbial safety standards. The obtained results suggest that the bread sample with 20% MOC addition (9.35 g protein, 12.32 g fat, 46.13 g carbohydrate, 4.29 g dietary fiber and 332.77 kcal per 100 g) should be selected for developing high nutritional bread product.

Comparison of the physicochemical properties and biological compounds of acerola fruit varieties grown in Vietnam through the various maturation stages

Dương Thị Ngọc Diệp, Ngô Xuân Nhi & Hoàng Quang Bình
Bản điện tử: 21 Jun 2024 | DOI: 10.52997/jad.3.07.2024
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Tóm tắt

The objective of the present study was to find the changes in physicochemical properties, bioactive compounds, and antioxidant activity of acerola fruits under different cultivars (i.e., Brazilian acerola (Malpighia emarginata D.C) and sour acerola (Malpighia glabra L.)) and maturation stages (unripe, half-ripe, and ripe). For any species, the study found an increase in total soluble solid and a* value, whereas there was a decrease in the content of bioactive compounds (i.e., polyphenols, flavonoids, vitamin C), total acidity, and antioxidant activity, which followed the maturation development of fruits. Briefly, the unripe acerola fruits (Brazillan cultivar) were an excellent source of vitamin C (32.97 mg/g) and phenolic content (25.62 mg GAE/g).