Vol. 17 No. 6 (2019)

The objective of this study was to clarify the current production, natural conditions, botanical characteristics, cultivation techniques, harvesting, processing, product preservation techniques, and consumption of the vine tea, Ampelopsis cantoniensis,in Tu commune, Dong Giang District, Quang Nam Province. Primary and secondary data were collected, analyzed and evaluated. The results indicated that the vine tea was mainly planted in autumn season from August to October with a density of 20,000 plants per hactare. Six to eight months after cultivation, the vines wereharvested for the first time. The vines can be harvested once a monthwith9-10 months each year, yielding about 6.0 tons of dryvineyields per hectare per year. In order to make thisvine tea become a local major commercial plant, it is necessary to focus on improving the commercial production and processing techniques. In addition, the vine tea production cooperativesof Tu commune and the local government authorities should promote large-scale production, monitor quality, establish a brand name and advertise the product.

On the basis of Dai Xuyen- 15Sea Duckherd, a selection towards increasing body weight to create HY1 male duck line was emplyedfor 2 generations. The purpose of the present studywasto evaluate some genetic parameters and body weight of HY1 male duck line. A total of 882 female and 176 male ducks were used at oneday of age in the starting generation.Fiftyfamilies were chosen for breedingeach generation. The genetic parameters and breeding valueswereestimated by VCE6 and PEST softwaresandthe growth curveswere fittedby Statgraphics software. Both males and females in generations 1 and 2 were selected based on the breeding valuefor body weight at 7 weeks of age. The results showed that: heritabilities forbody weight ofDai Xuyen - 15Sea Ducks at 1 day of age, and at 4 and 7 weeks of age were 0.36-0.41; 0.19-0.20 and 0.16-0.26, respectively. After 2 selective generations, the body weight at 7 weeks of age of HY1 line reached 2553.37gfor male and 2609.72 gfor female, higher than the startinggeneration(185 and 172 g/individual, respectively) equivalent to 8 and 7%, respectively. Growth analysis indicated thatthrough selective generations, males and females had faster growth rates, due to shorter earlier lagginggrowth phase and the higher weight body at the end of thephase. After 2 selective generations,the body weightandbodygrowth of HY1 line were improved markedly.

This study evaluated the effectiveness of adding different types of gutweed powder on the growth and survival rate ofblood cockle (Anadara granosa) at the juvenile rearing stage. The blood cockle seeds with initial shell length of 4.71 ± 0.03 mm were stocked in the PVC tanks with aeration system. There were four feeding treatments with triplicates eachas follow: 1) 100% algae from Tilapia-Green water system (GW, control treatment), 2) GW + gut weed powder, 3) GW + gutweed powder fermented with Saccharomyces cerevisiae, and 4) GW + gut weed powder fermented with Bacillus subtilis. After 60 days, the highest survival rate was recorded in GW (75.3%) and this was significantly different from other treatments (p0.05). The lowest survival rate was observed in GW + gut weed powder fermented with yeast (56.9%). Blood cockles obtained the highest shell weight and length in cockles fed GW+ gut weed powder fermented with B. subtilis(70.0 ± 1.6 mg and 6.18 ± 0.04 mm, respectively). Our findings suggested that adding gut weed powder fermented with B. subtiliscan improve the growth performance of juvenile blood cockles.

This study was carried out to assess probiotics addition on Vibrioin culture medium and the growth performanceof poslarval white-leg shrimp (Litopenaeus vannamei) usingbiofloc technology. The postlarvae (0.007g/ind.in weightand0.90 cmin length) were nursed at 2postlarvae/lin 100 L tank containing 50 lof 30 ‰ seawater. Probiotics were daily added at 0.01 g/l(recommended concentration) and ½, 2 times, 3 times and 4 times reccomnended concentration compared to the control (without probiotics added). Results showed that after 20-day of culturethe ratio of Vibrio/total bacteria was lower in the probiotics addition treatment than the control. The individual length and weight of shrimps increased in all treatments when probitic added, especially the shrimps with three-times higher recommended concentration of probiotics significantly (P< 0.05) increasedin length and weight than that in the control treatment. The results of this study indicated that the ratio of Vibrio/total bacteria was reduced and shrimp growth performace improved when probiotics was combined withbiofloctechnology.

A study ontheefficiency of hard clam farming in earthen ponds was conducted in Ben Tre and Nam Dinh provinces to assess the growth, survival rates,economic efficiency and food safety of farmed clamsin commercial production. Two earthen ponds (total areaof 1.8ha) in Ben Tre province and four earthen ponds (total area of 2.2 ha) in Nam Dinh province were used in thisstudy. The results showed that the growth rate of clamswas seasonally affected and it fluctuated in the range of 1.27-1.39 g/month. The survival rate of clams varied from 70.65 to 90.00% and there existeddifference in two study areas. The clamscultured in Ben Tre province had higher survival rate than those in Nam Dinh province. The harvested size varied from 48 to 55 individual/kg and the harvested clamsmet the standards of food hygiene and safety. The clam productivity in two areas ranged from 22.08 to 24.55 tonnes/ha/crop and the profit varied between19.86 million VND/ha to 26.86 million VND/ha and/crop. The marginalcost benefit ratioin Ben Tre (0.28) were higher than that in Nam Dinh (0.22). The results of the study confirmed the ability of the clam farming model in earthen pond in the coastal areasof ​​Vietnam.

The evaluation of factors affecting the winning price of auction of residential land use rights in Ha Long city, Quang Ninh province has aim to propose solutions to improve auction efficiency of residential land use rights. The data was analyzed through Cronbach’s Alpha coefficient, exploratory factor analysis and linear regression model. In the period 2016-2018, Ha Long City has 27 projects auctioning residential land use rights with 256 parcels of land. Survey results of 105 winning bidders show that the land use right market factor has the biggest influence (19.98%), followed by the parcel, financial factor, auction performance and other factors correspond to the impact rates of 15.93%, 14.55%, 13.13% and 12.29%, the law factors with the smallest influence (8.62%). In order to improve the auction efficiency of residential land use rights, it is necessary to complete the method of determining the reserve price for auction of residential land use rights; determining financial obligations when participating in an auction; diversifying the form of notice on land auction and sale, submitting land auction participation dossiers; shortening the time to carry out the procedures after winning the land auction; completing the dissemination of land auction regulations.

The present study was carried out evaluate the semen quality improvement of American Bullystud dog using extracts of Curculigo orchioidesandHerba Cistanches Caulis Cistanchis. Powdered herbs were soaked in 70% ethanol solvent and steeped for 72 hours before being filtered. The filtrates were then vacuum rotatedandlyophilized to obtain the dried extracts. The resultsshowed that, using ethanol 70% solvent, the extractionefficiency of Herba Cistanches Caulis Cistanchis(9.938%) was two times higher thanCurculigo orchioides(4.453%). The extract of Curculigo orchioidesand Herba Cistanches Caulis Cistanchissupplemented at a dose of 50 mg/day/dog in the diet increased the quality of American Bully semen. The volume of semen per each ejaculation increased from the control by0.62 mL(supplemented with Herba Cistanches Caulis Cistanchisextract) and 1.06 mL(supplemented with Curculigo orchioides). The total number of sperms moving straight ahead per each ejaculation increased compared to the control group of 266.92 million sperms (supplemented withCurculigo orchioidesextract) and 208.83 million sperms (supplemented with Herba Cistanches Caulis Cistanchisextract).

The sea salt production in Vietnam depends too much on the weather, natural disasters... The preservation of salt is still manual and there is much loss. The purpose of the article is to propose the design solution to preserve brine and salt in the sea salt production and processing system. By design calculation method, a model of salt storage tanksfor preserving brine and sea salt was created. Easy-to-make equipment, easy-to-find and easy-to-use materials will contribute to reducing losses, improving productivity, quality, and reducing costs per unit of sea salt products in Vietnam.

A random survey of 135 households from 6 communes in Thanh Mien and Cam Giang districts, Hai Duong province was conducted to determine the nitrogen emission and technical efficiency in pig production.The results showed that the education and experiences of the household heads andparticipation in agricultural extension activities had a positive effect on the technical efficiency of pig production. The factors such as the type and location of piggery have a positive influence on the technical efficiency. Moreover, the finishfarm householdshave lower technical efficiency than the farrow-to-finish farm househlods. It is thus recommendedthat the policy makers can refer to our results to help pig farmers improve their pig production performance. At the same time, stronger interventions from the government are needed to reduce the pressure ofpig wastesto the environment.

The study was conducted to assess the quality of human resources for Thai Nguyen province’s small and medium-sizedenterprises inthe fourth Industrial revolution. Along with the secondary data, the research used primary data from a survey ofthe employersand employeesin Thai Nguyen’s small and medium-sizedenterprises. The primary data wereanalyzed by Cronbach’s Alpha coefficient,descriptive statistics, and comparative statistics. The results showedthat the quality of human resources inThai Nguyen’s small and medium-sizedenterprises werelow and havenot met the labor requirements forthe Industry 4.0. The study proposedsome solutions to improve the quality of human resources for Thai Nguyen’s small and medium-sized enterprises inthedigital revolution.