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• Effect of Salinity on Reproductive Performance of SelectedBrackish Water NileTilapia Strain (Oreochromis niloticus)

  Le Minh Toan, Vu Van Sang, Trinh Dinh Khuyen

  Date Received: 27-09-2012 / Date Accepted: 18-12-2012

   Abstract PDF (VIETNAMESE)

  The experiment was carried out to evaluate the effects of salinity on fertility of selected brackish water Nile tilapia (Oreochromis niloticus) strain in 53 days. The experiment fish was arranged breeding in brackish water corresponding to three different salinity levels such as: 4 - 5‰, 8 - 10‰ and 14 - 16‰, the ratio of male: female tilapia was 1:2, each formula was repeated 3 times in 3 different tanks, stocking density was 4 individuals/m3 for each tank. Results show that the reproductive rate of females corresponding to 4 - 5‰ salinity was 26.2 ± 4.64%; 8 - 10‰: 17.86 ± 11.21% and 14 - 16‰: 6.88 ± 6.57%. The number of eggs per formula obtained after 7 times was obtained in 3 corresponding levels salinity was 5,229a ± 1,280 eggs, 2,721b ± 1,559 eggs and 923c ± 706 results. Relative fecundity 3 levels of salinity 4 - 5‰, 8 - 10‰ and 14 - 16‰, respectively, 4.3a ± 0.63 eggs/g fish/time was 3.36b ± 0.67 eggs/g female/times and 1.7c ± 1.27 eggs/g fish/time. Absolute fecundity of tilapia in salinity 4 - 5% was 829 ± 122.9 eggs/time delivery, salinity 8 - 10‰ of 678a ± 135,7 and at a salinity of 14 - 16‰ was 403b ± 154.5 eggs/female/delivery time. Natural frequency of females at 4 - 5‰ salinity 22.3 ± 2.23 days; 8 - 10% was 24.9 ± 3.7 days and 14 - 16‰ salinity was 25.7 ± 2.59 days. Experimental results showed that the breeding of tilapia at salinity level of 4 - 5‰ obtained the best reproduction, next to the level of salinity 8 - 10‰. Experiments show that the breeding of Nile tilapia at salinity level below 8 - 10‰ was high practical significance.

• Effects of Synbiotics of Pediococcus pentosaceus and Fructooligosaccharide on the Growth Performance, Feed Utilization, and Digestive Enzyme Activity of Nile tilapia (Oreochromis niloticus)

  Ton That Chat, Tran Van Hoang, Hoang Nghia Manh

  Date Received: 06-02-2025 / Date Published: 20-02-2025

   Abstract PDF (VIETNAMESE)

  This study aimed to evaluate the influence of synbiotics consisting of P. pentosaceus and Fructooligosaccharide (FOS) at different levels on growth rate, feed efficiency, and digestive enzymes of Nile tilapia. Fingerlings (mean weight of 5.78 ± 0.15g) were fed commercial pellets supplemented with only P. pentosaceus (at a density of 108 CFU/ml) served as control treatment (CT) and the treatment fish groups were fed commercial pellets supplemented with synbiotics containing P. pentosaceus (108 CFU/ml) mixed with FOS at three levels, including 0.25% (NT1), 0.5% (NT2), and 1.0% of the total amount of feed (NT3), respectively. After 60 days of the feeding trial, the results showed that the fish fed with the diets supplemented with synbiotics exhibited a better growth rate and improved feed efficiency compared to the control. Furthermore, fish fed with synbiotics significantly enhanced digestive enzyme activities compared to those in the control group (P <0.05). The results of this study suggest that using synbiotics containing P. pentosaceus and FOS at a level of 0.5% of the diet is recommended to improve the growth rate, digestive enzyme activity and feed efficiency of the Nile tilapia.

  DOI: https://doi.org/10.1234/198zk415

• Effect of Dietary Fucoidan Supplementation on Growth of Nile Tilapia (Oreochromis niloticus)Fingerlings and Improvement of Survival Rate of Fish when Infected with Aeromonas veronii

  Tran Anh Tuyet, Nguyen Thi Mai, Nguyen Thi Dung, Tran Thi Nang Thu

  Date Received: 18-05-2021 / Date Accepted: 21-02-2022

   Abstract PDF (VIETNAMESE)

  The study was conducted to evaluate the effect of dietary fucoidan extracted from brown seaweed Sargassum swartziion growth, survival rate, feed conversion ratio (FCR), and disease resistance to Aeromonas veroniibacterium in Nile tilapia (Oreochromis niloticus) fingerlings. Fish (23.2 ± 2.7g) were fed the commercial feed (35%Pr) supplemented with fucoidan at various concentrations (0%, 0.05%, 0.1%, 0.5%) in triplicate for 6 weeks. The results have showed that fucoidan did not significantly affect (P >0.05) the growth, survival, and FCR during the feeding trial. At the end of nutritional trial, fish were infected with Aeromonas veroniiat dose of LD50 (7.82 ×104CFU/ml), fish were then monitored for 10 days, the mortality was daily recorded. After 10 days of challenge, the results showed that the survival rate was 76.6% and 80% for 0.1% and 0.5% fucoidan-fed fish, respectively, much higher than other groups (30% and 36.7% for Control and 0.05% fucoidan-fed fish, respectively) (P < 0.05). In conclusion, dietary fucoidan extracted from brown seaweed Sargassum swartziiat 0.1 and 0.5% enhanced the resistance of tilapia fingerlings against to Aeromonas veronii.

• Influence of Dietary Peptidoglycan and Probiotics Supplementattion on Growth Performance, Feed Utilization,Survivaland Hematological Parameters in Nile Tilapia(Oreochromis niloticus)

  Nguyen Thi Mai, Litpaya Nettavongsa, Le Thi Cam Van, Ho Hai Yen

  Date Received: 16-03-2023 / Date Accepted: 23-05-2024 / Date Published: 12-06-2025

   Abstract PDF (VIETNAMESE)

  The present study was conducted to evaluate the effects of dietary co-supplementation of peptidoglycan and probiotics on growth performance, survival, feed utilization, and hematological parameters in Nile tilapia. Commercial feed specialized for tilapia were supplemented with peptidoglycan and probiotics at various concentration (g/kg of diet): 0; 3+3; 5+3; 5+5; 3+5 corresponding to experimental treatments: NT1, NT2, NT3, NT4, NT5. Nile tilapia juveniles were fed on the experimental feed for 4 weeks at a ration of 5% body weight; the feed amount was daily recorded. During the feeding period, fish were weekly weighed to monitor the fish growth. After a 4-week trial, blood samples were collected for hematological analysis; the fish number and weight were used to determine the survival rate and fish growth. Results show that the co-supplementation of probiotics and peptidoglycan induced positive effects on the fish survival, growth, and feed conversion ratio, in which fish fed 3g peptidoglycan + 3g probiotics displayed the best results.

  DOI: https://doi.org/10.31817/tckhnnvn.2024.22.5.

• Survival rate and final weight at harvest of hybrid combinations of Nile tilapia (Oreochromis niloticus) as influenced by genetic background of parental populations

  Nguyen Hong Diep, Vu Van Sang, Vu Hong Su, Nguyen Cong Duong, Tran Thi Kim Oanh, Do Son Tung

  Date Received: 13-12-2021 / Date Accepted: 05-04-2022

   Abstract PDF (VIETNAMESE)

  This study was designed to estimate the additive genetic, heterotic, and maternal effects on harvest body weight and survivalof tilapia (Oreochromis niloticus) combinations in a 4x4 complete diallel cross involving four populations, i.e. NOVIT, GIFT, China, and the Philippines. Mass spawning method was applied to produce hybrid combinations (with 60 males and 60 females per cross) for testing on harvest body weight and survival at three locations, Quang Nam, Tien Giang and Bac Ninh. A total of 8,001 Nile tilapia was evaluated after a grow-out period of 6 months. A linear mixed model was used to estimate strain additive genetic, heterotic, and maternal effects for body weight and survival at harvest. Research results showed that the non-additive genetic (heterotic) effects were small and not significantly different from zero for the traits studied, whereas the additive genetic effects were statistically significant (P <0,001). Based on heterotic and additive genetic effects among crosses, pure crosses between Novit and Novit showed the highest additive genetics effects, while different strain cross between Novit and the Philippines indicated the best additive genetics effects.