Published: 2021-02-26

Genetic parameter estimates for resistance to Enteric Septicemia of Catfish on Pangasianodon hypophthalmus

Phuc H. Tran, Dung T. P. Tran, Sang V. Nguyen, Vu T. Nguyen, Phuong H. Vo, & Lien T. B. Huynh
Electronic version: 26 Feb 2021 | DOI: 10.52997/jad.6.01.2021
Abstract | PDF (343.4K)

Abstract

Genetic parameters were estimated for resistant traits against Enteric Septicemia of Catfish (ESC) on the first generation of selection on striped catfish. In total, 8,207 and 5,838 individuals from 147 and 130 full-sib families were challenged byEdwardsiella ictaluricausing ESC on fingerlings and tested growth in pond accordingly. Harvest body weight (HW), length (HL) and survival (SURGROW) from grow-out test and ESC resistant traits such as binary alive-dead survival (SUR) and time to dead (TIME) at different truncated points from challenged test of fingerlings were recorded. Heritability for each trait and genetic correlations among these recorded traits were estimated. High heritabilities were found for HW (0.48) and HL (0.47), and mostly from medium to high values were estimated for SURGROW (0.23), SUR (0.13 - 0.40) and TIME (0.25 - 0.39). Genetic correlations among different truncated SUR and TIME traits were almost highly positive (0.57 - 0.99). Genetic correlations among different truncated SUR and TIME traits with HW and SURGROW were low positive (0.10 - 0.40). In summary, selection for ESC resistance would not negatively affect the growth in fingerling stage.

The effectiveness of Saccharomyces cerevisiaein inhibiting aflatoxin production andreducing the harmful effects of aflatoxin in ducklings

Hai N. Nguyen, & Anh T. N. Le
Electronic version: 26 Feb 2021 | DOI: 10.52997/jad.4.01.2021
Abstract | PDF (311.5K)

Abstract

Sacharomyces cerevisiae isolates were obtained from baker’s yeast, soil, fruit and identified with PCR. Twenty seven isolates of S. cerevisiae were screened for capacity of inhibition of aflatoxin production of Aspergillus flavus (A. flavus) on coconut extract agar media (CEA). The results showed that the co-culture method of S. cerevisiae isolates and aflatoxin producing A. flavus on CEA medium could be used for screening the strains that are able to antagonize aflatoxin-producing A. flavus. Onground corn medium, with the rate of 104 aflatoxin-producing A. flavus spores and 108S. cerevisiaeyeast cells/g, S. cerevisiaewas able to reduce the amount of aflatoxin produced by A. flavusin corn. In an in vivo experiment, it was found that addition of 108 cells of S. cerevisiaeto one kg of duck feed contaminatedwith 300 ppb aflatoxin from 1 to 10 days of age reduced adverseeffects of aflatoxin on the liver and kidneys of ducks.

Efficacy of fluralaner in drinking water in controlling mite and improving welfare in laying hens

Hien T. Le, Nam T. T. Nguyen, Nguyen T. N. Nguyen, Dung T. Nguyen, & Ha H. Truong
Electronic version: 26 Feb 2021 | DOI: 10.52997/jad.5.01.2021
Abstract | PDF (2.3M)

Abstract

The objective of the experiment was to evaluate the effectiveness of Exzolt (contaning fluralaner) to control mite and improve behavior relating to welfare in layers. Monitoring and recording indicators of livestock productivity, level of mite infection, number of eggs with red dots, and behavior of hens before and after using Exzolt were performed. 4 cameras to monitor hens’ behavior from 18 pm of the previous night to 6 am of the following morning were installed to record the layer’s behavioral indicators caused by the mite including number of shakes, wing flaps, scratches, preening, bites, pecking (aggressive), before and after using Exzolt. As a result, the studied farm was heavily infected with mites with an average infection level of 1.79 on a scale of 0 - 2. After the treatment with Exzolt, the farm became totally free of the mites in layers for many weeks thereafter. The use of Exzolt did not affect daily feed intake, mortality. The proportion of eggs with red spots decreased significantly. Especially, the layer’s behavioral expression causing annoying was significantly reduced after using Exzolt. This is the reason for good recommendation to used this product to control mite for layer farm.

Genetic parameter estimates for important traits on the fifth generation in red tilapia in Vietnam

Sang V. Nguyen, Phuc H. Tran, Truong V. Dang, & Khoa D. Pham
Electronic version: 26 Feb 2021 | DOI: 10.52997/jad.7.01.2021
Abstract | PDF (314.5K)

Abstract

Genetic parameters comprising heritability, genetic correlation and geno-type by environment interaction (GxE) for growth survival rate and body colour at harvest were estimated on the 5th selective generation of red tilapia grown in two environments, freshwater and brackishwater ponds. A total of 116 full- half-sib families was produced as well as 4,432 and 3,811 tagged individuals were tested in freshwater and brackishwater ponds, respectively. Genetic parameters were estimated by ASReml 4.1 software. The heritability for body weight and survival rate was high while medium heritability for body colour in freshwater was observed. The heritability for those traits of red tilapia in brackishwater. Together with the figures in earlier publication on previous generations (G1 to G4) in the same selective population, the expected medium to high re-sponse acquires if selection is done for each trait. Genetic correlations among harvest body weight, survival rate and body colour are insignifi-cantly different and ranging from -0.25 to 0.37 (P > 0.05). These results implied that selection on one trait do not influence on responses of the other traits. GxE interaction for body weight and body colour between two tested environments is mostly negligible with genetic correlations ranging from 0.63 - 0.80 while it is important for survival trait (rg= -0.17±0.40).

Release kinetics of lime essential oil (Citrus aurantifolia) from beads microencapsulated through ion-gel method

Vinh Truong, Phuong T. Nguyen, Nhung T. C. Pham, & Phuong T. Nguyen
Electronic version: 26 Feb 2021 | DOI: 10.52997/jad.8.01.2021
Abstract | PDF (448.3K)

Abstract

Ca-Alginate beads for microencapsulation of lime oil (Citrus aurantifolia) by ion-gel method was manufactured and then soaked in Chitosan solution to obtain Ca-Alginate-Chitosan beads. Increased CaCl2 concentrations reduced lime essential oil release. The alginate concentration (2 to 3%) and water temperature affected significantly the release of oil (P< 0.05). The higher temperatures, the higher the release rate. The oil release  at 75oC was twice as much as at 45oC. At 45oC, the difference in the release rate among the alginate concentrations of 2%, 2.5% and 3% was clear and statistically significant (P< 0.05). However, at 60oC and 75oC, there was no significant difference in release between the alginate concentration of 2.5% and 3% (P > 0.05). In the storage of beads in 1% CaCl2 solution at normal temperature, after the first 15 days, Ca-Alginate-Chitosan system released about 3% slower than Ca-Alginate system, but there was no difference between the two systems after 45 days. This shows that if prolonged for a long time, the ion-gelation of Ca-Alginate prevails over the Alginate-Chitosan cross-link.

Evaluation of the general combining ability of S4 cherrytomato selfing lines and growth performance of the S5 lines

Hiet D. Hoang, Tuan Q. Huynh, Lam V. Tran, Trinh T. T. To, Bich T. Thai, & Dan T. Vo
Electronic version: 26 Feb 2021 | DOI: 10.52997/jad.3.01.2021
Abstract | PDF (622.2K)

Abstract

The study aimed to determine the suitable cherry tomato lines for using as a hybrid material production. Experiments were arranged in sequence without repeating. The results from estimating the General Combining Ability (GCA) of 25 tomato S4 selfing lines showed that ten S4 lines (D3.4; D10.4; D11.4; D12.4; D14.4; D15.4; D17.4; D19.4; D21.4 and D25.4) performed high GCA values based on the practical yield characteristic. Ten tomato S5 selfing lines were characterized by yielding 41.49 - 50.57 tons per ha, red ripened fruit, high brix values of 6.9 - 8.1% and medium resistance to Phytophthora infestans disease. In brief, those tomato lines could be a suitable material source for the production of F1 - hybrid tomatoes.

Effects of pre-sowing seed treatment with KCl on yield and quality of two peanut cultivars L12 and L18

Trong V. Le, & Hien T. T. Vu
Electronic version: 26 Feb 2021 | DOI: 10.52997/jad.1.01.2021
Abstract | PDF (350.2K)

Abstract

The study was conducted to evaluate the effect of 0.05% KCl on yield and quality of two peanut varieties L12 and L18 grown in Thanh Hoa province. The experiment was arranged in a completely randomized design with two factors (varieties and chemicals). After careful selection, L12 and L18 seeds were divided into two parts. Part 1 was treated with distilled water as control and part 2 was treated with 0.05% KCl. The results showed that pre-sowing seed treatment with 0.05% KCl increased the yield components and yield of both L12 and L18 when compared to the control, in which the yield of L18 in both treatments reached 37.37 quintals/ha and 39.54 quintals/ha and was higher than that of the L12 variety at 35.77 quintals/ha and 36.40 quintals/ha. Pre-sowing seed treatment with 0.05% KCl also increased the quality of peanuts such as starch content, reducing sugar, lipid, saponification value, protein, B vitamins, total amino acids and content of some mineral elements in peanuts such as N, K, Ca, Mg. Briefly, the results of this study indicated that pre-sowing seed with KCl increased the yield and quality of peanuts.

Effect of nitrogen fertilizer rates on growth and oil yield of Java lemongrass (Cymbopogon winterianus Jawitt) in Thu Duc, Ho Chi Minh City

Anh T. L. Phan, Lan P. H. Nguyen, Thuan T. H. Pham, & Tuyen A. Hoang
Electronic version: 26 Feb 2021 | DOI: 10.52997/jad.2.01.2021
Abstract | PDF (300K)

Abstract

Java lemongrass is commonly cultivated in Vietnam for the use in industries and traditional medicine. Currently, the application of fertilizer, especially nitrogen fertilizer, is one of the most traditional farm practices to increase production yield. A single factorial experiment was carried out in a completely randomized design, three replications to determine the suitability of nitrogen fertilizer rates on growth, leaf and oil yields of Java lemongrass. Six treatments were used in this experiment including 90, 120, 150, 180, 210, 240 kg N/ha and applying 90 kg N/ha as control. Fertilizer base for treatments (for 1 ha) included 20 tons of cow dung compost, 60 kg P2O5 and 60 kg K2O. The application of 120 kg N/ha significantly improved the growth of Java lemon-grass as plant height (97.0 cm/plant), average number of leaves (197.1 leaves/plant), average weight of leaves per plant (198.7 g/plant), fully leaf yield (9.4 tons/ha/2 harvest times), essential oil content (1.0% FW) and economic oil yield (97.8 kg/ha/2 harvests).