Chanagun Chitmanat

Effects of Cordyceps militaris spent mushroom substrate and Lactobacillus plantarum on mucosal, serum immunology and growth performance of Nile tilapia (Oreochromis niloticus)

ABSTRACT An 8‐weeks feeding trial was performed to investigate the possible effects of supplementation of Nile tilapia diet with Cordyceps militaris spent mushroom substrate (SMS) single or combined with Lactobacillus plantarum on immune parameters and growth performance. For this aim, Nile tilapia fingerlings were fed with four experimental diets namely: Diet 1 (0 – control), Diet 2 (10 g kg−1 SMS), Diet 3 (108 CFU g−1 L. plantarum), and Diet 4 (10 g kg−1 SMS + 108 CFU g−1 L. plantarum). At the end of feeding trial, skin mucus parameters, serum immune parameters, and growth performance were measured. The results indicated that supplementations SMS + L. plantarum or/and resulted in a significant increase in skin mucus lysozyme and peroxidase activities compared with the control group after 8 weeks of feeding trial (P < 0.05). The highest values of these parameters were recorded for fish fed both SMS + L. plantarum supplementations. Nonetheless, no significant difference was recorded between other supplemented groups (P < 0.05). For serum immunology, the results showed that serum lysozyme activity, alternative complement, phagocytosis, serum peroxidase, and respiratory burst activities were significantly higher in supplemented groups compared to the control (P < 0.05). The highest values were recorded in fish fed both SMS and L. plantarum with respect to the individual application. No significant differences were observed between fish fed SMS and L. plantarum (P < 0.05). Results on growth performance indicated that fish fed supplemented diets showed a statistically significant increase in the specific growth rate (SGR), weight gain (WG), final weight (FW) compared to the control group (P < 0.05). The highest SGR and WG values were observed in fish fed both dietary SMS and L. plantarum. However, no significant differences in these parameters were observed in fish fed SMS or L. plantarum alone (P > 0.05). The FCR was significantly lower in fish fed 10 g kg−1 SMS + 108 CFU g−1 L. plantarum than in other groups, while control group presented the highest values (P < 0.05). The present results suggested that the combination of these natural substances could be considered as potential feed‐additives for aquaculture farmed fish. HighlightsO. niloticus fed with 10 g kg−1 SMS or 108 CFU g−1 L. plantarum enhanced growth performance.Fish fed diet 10 g kg−1 SMS or 108 CFU g−1 L. plantarum stimulated mucosal and serum immunology.Combined of 10 g kg−1 SMS and 108 CFU g−1 L. plantarum enhanced growth and innate immune of the fish.

Climate risk management in river-based tilapia cage culture in northern Thailand

Purpose – The purpose of this paper is to analyse how fish farmers manage climate-related risks and explore possible ways to strengthen risk management under current and future climate. Design/methodology/approach – In total, 662 fish farmers in sites across Northern Thailand were interviewed about risks to the profitability of their fish farms and ways such risks were managed. Nonlinear canonical correlation analysis was used to relate risk factors to management practices at farm and river levels. In total, 68 in-depth interviews with farmers and other stakeholders provided additional information on climate risk management practices. Findings – Farmers use a combination of adjustments to rearing practices, cropping calendars and financial and social measures to manage those risks, which they perceive as being manageable. Many risks are season, river and place specific; implying that the risk profiles of individual farms can vary substantially. Individual risks are often addressed through multiple practic...

Effects of Cordyceps militaris spent mushroom substrate on mucosal and serum immune parameters, disease resistance and growth performance of Nile tilapia, (Oreochromis niloticus)

Abstract The aim of present study was determination effects of dietary administration of C. militaris spent mushroom substrate (SMS) on mucosal and serum immune parameters, disease resistance, and growth performance of Nile tilapia (Oreochromis niloticus). Two hundred twenty five fish of similar weight (37.28 ± 0.10 g) were assigned to the following diets [0 (T1‐ Control), 5 (T2), 10 (T3), 20 (T4) and 40 g kg−1 (T5) SMS]. After 60 days of feeding trial, growth performance, skin mucus lysozyme and peroxidase activities as well as serum innate immune were measured. In addition, survival rate and innate immune responses were calculated after challenge test (15 days) against Streptococcus agalactiae. The results revealed that regardless of inclusion levels, feeding Nile tilapia with SMS supplemented diets significantly increased skin mucus lysozyme and peroxidase activities as well as serum immune parameters (SL, ACH50, PI, RB, and RB) compared control group (P < 0.05). The highest increment of immune parameters was observed in fish fed 10 g kg−1 SMS which was significantly higher than other treatments (P < 0.05). Also, the relative percent survival (RSP) in T2, T3, T4, and T5 was 61.11%, 88.89%, 66.67, and 55.56%, respectively. Among the supplemented groups, fish fed 10 g kg−1 SMS showed significant higher RPS and resistance to S. agalactiae than other groups (P < 0.05). Regarding the growth performance, SGR, WG, FW, and FCR were remarkably improved (P < 0.05) in SMS groups; the highest improvement observed in 10 g kg−1 SMS treatment. According to these finding, administration of 10 g kg−1 SMS is suggested in tilapia to improve growth performance and health status. HighlightsTilapia fed 10 g kg−1 SMS significantly stimulated mucosal and serum immune response.Diet of 10 g kg−1 SMS significantly increased survival rate of O. niloticus against S. agalactiae.Fish fed 10 g kg−1 SMS significantly enhanced growth performance and feed conversion ratio.

Tilapia diseases and management in river-based cage aquaculture in northern Thailand

ABSTRACT A total of 662 farmers who rear tilapia in river-based cages in Northern Thailand were interviewed on their knowledge and perception on disease constraints and their control measures. Most farms (84%) had disease problems in the last two years. Exophthalmia ranked higher than other clinical signs. Most farmers noticed that the risk of disease problems was similar every month. Most (95%) believed that fish diseases were caused by bacterial pathogens. To treat perceived disease outbreaks, most farmers (96%) removed infected and dead fish and applied, usually inappropriately, antibiotics. As disease prevention through good management is better than treatment, farmers and fish disease experts could use these research findings as a tool to work together to develop better control strategies.

Access to Fish Cage Aquaculture in the Ping River, Northern Thailand

Aquaculture in rivers and other public water bodies raises issues of access and property rights. Over the past few years an industry has developed around the rearing of hybrid red and Nile tilapia (Oreochromis niloticus L.) in cages in the Ping River in northern Thailand. In this article we report on a study of how households gain access to river cage sites to farm fish. The findings are based on a case-control study of 400 households, half of which had a history of fish farming and half which did not. Additional information was gathered from qualitative in-depth interviews with 93 stakeholders. Households with good access to farming sites, financial capital, and social networks are more likely to farm fish. Proximity to the river front was a very important factor and operated at a micro-level within villages with river borders. Land and vehicle assets were also associated with fish farming—more so than monthly income levels—probably because they reflect access to credit. Social capital measured as belonging to various kinds of groups was also associated with fish farming, but may have been in part an outcome rather than a pre-requisite. Many fish farmers start through encouragement and invitations by firms or the fisheries department. Sites for cage aquaculture in rivers have characteristics somewhere between a private and a club good: those who don’t live near the river are usually excluded, but rivalry for sites among those who live close becomes an issue with congestion of farms arising from expansion in number of cages or other factors that reduce availability of suitable rearing sites like variability in climate, water flows, water quality, and government regulations.

Managing the risks from the water-related impacts of extreme weather and uncertain climate change on inland aquaculture in Northern Thailand

ABSTRACT Climate change will have significant impacts on inland aquaculture. This article assesses the robustness of a set of potential adaptation strategies for Northern Thailand using a rule-based assessment model to synthesize information from secondary sources, fish farmers, officials and experts. The net benefits of different strategy types vary substantially with water demand and fish demand, as well as future climate. No-regret and low-regret strategies are worthwhile under a broad range of conditions, but may not be sufficient to maintain profitability as the negative impacts of climate change unfold. The main implication is that adaptation pathways must be flexible.

Effects of orange peels derived pectin on innate immune response, disease resistance and growth performance of Nile tilapia (Oreochromis niloticus) cultured under indoor biofloc system

&NA; The present study investigates the effects of orange peels derived pectin (OPDP) on skin mucus and serum immune parameters, disease resistance and growth performance of O. niloticus cultured under indoor biofloc system. Six hundred Nile tilapia (average weight 9.09 ± 0.05 g) were distributed into 15 fiber tanks (300 L per tank) assigned to five treatments repeated in triplicate. Fish were fed experimental diets contain different levels OPDP as follows: 0 (control in clear water), 0 (control in biofloc system), 5, 10, and 20 g kg−1 OPDP for 8 weeks. At weeks 4 and 8 post feeding, skin mucus lysozyme (SMLA), peroxidase activities (SMPA), serum lysozyme (SL), serum peroxidase (SP), alternative complement (ACH50), phagocytosis (PI), and respiratory burst activities (RB) as well specific growth rate (SGR), weight gain (WG), final weight (FW), and feed conversion ratio (FCR) were measured. Also, resistance against Streptococcus agalactiae was assessed after 8 weeks post‐feeding. Nile tilapia fed OPDP supplemented diets had significantly higher SMLA and SMPA compared to the controls (P < 0.05). The maximum values were observed in tilapia fed 10 g kg−1 OPDP followed by 5 and 20 g kg−1 OPDP. Nevertheless, no significant differences were observed between these two supplemented diets and between the control groups (P > 0.05). Regarding the serum immunological parameters, dietary inclusion of 10 g kg−1 OPDP showed significant higher SL and PI than other supplemented groups and control groups (P < 0.05). However, no significant differences were observed in SL and PI of fish fed 5 and 20 g kg−1 OPDP (P > 0.05). Dietary administration of OPDP significantly increased SP and ACH50 compared to the controls (P < 0.05), regardless of inclusion level. Additionally, non‐significant change was found in RB of OPDP fed fish when compared with the controls (P > 0.05). The challenge test revealed that relative percent of survival (RPS) in OPDP treatments were 45.45%, 81.82%, 50%, respectively. The highest RPS was noticed in fish fed 10 g kg−1 OPDP. Furthermore, dietary administration of OPDP significantly improved SGR, WG, FW, and FCR (P < 0.05). Overall, the present findings suggested that OPDP can be taken into account as functional feed additives for O. niloticus. HighlightsDiet of 10 g kg−1 OPDP significantly stimulated innate immune response of tilapia culture under in door biofloc system.Inclusion of 10 g kg−1 OPDP significantly increased survival rate of O. niloticus against S. agalactiae.Fish fed 10 g kg−1 OPDP significantly improved growth performance and feed conversion ratio.

Mainstreaming climate change adaptation into inland aquaculture policies in Thailand

ABSTRACT While there have been many pilot projects on adaptation undertaken in the fisheries and aquaculture sector, state policies are only just beginning to address let alone refer to climate change. This study explores the climate-related content, climate sensitivities, and opportunities to incorporate climate change concerns in a set of aquaculture policies by the government of Thailand. The analysis is based on content analysis of policy documents and in-depth interviews with 14 officials that had roles in the design or implementation of 8 Department of Fisheries policies. The Aquaculture Master Plan 2011–2016 and the now abandoned Tilapia Strategy refer directly to climate variability or change. The Master Plan also suggests measures or strategies, such as investment in research, and the transfer of technologies, which would be helpful to sustainability and adaptation. Other policies suggest, or at the very least include, practices which could contribute to strengthening management of climate-related risks, for example: a registration policy included provisions for compensation; extension programme policy recognizes the importance of extreme events; and a standards policy gives guidance on site selection and water management. Most existing aquaculture policies appear to be sensitive to the impacts of climate change; for instance, the zoning policy is sensitive to spatial shifts in climate. Stakeholders had ideas on how policies could be made more robust; in the case of zoning, by periodically reviewing boundaries and adjusting them as necessary. POLICY RELEVANCE This study is one of the first evaluations of the coverage and sensitivity of aquaculture policies to climate change. It shows that while existing policies in Thailand are beginning to refer explicitly to climate change, they do not yet include much in the way of adaptation responses, underlining the need for identifying entry points as has been done in this analysis. Further mainstreaming is one option; another possibility is to adopt a more segregated approach, at least initially, and to collect various policy ideas under a new strategic policy for the aquaculture sector as a whole.