Explore groundbreaking research on Progres® Liquid's impact on Asian seabass presented at Aquaculture Europe 2023. Discover how this novel feed ingredient enhances growth, immunity, and disease resistance in aquaculture
More than 2300 aquaculture professionals gathered to Vienna, Austria, for Aquaculture Europe Conference 2023 on September 18-21. One of the largest theme of the meeting were alternative feed ingredients for the aquatic farmed species. The aqua-sector is rapidly expanding, so novel, sustainable and functional feed ingredients are in high demand.
Progres®: A Novel Feed Ingredient for Aquatic Species
A recent study showed that Progres® Liquid, developed by Hankkija Oy and owned by AB Vista, UK, is one of the most promising novel feed ingredients for the aquatic species. The study was conducted with Asian seabass (Lates calcarifer) in the Kasetsart University, Thailand, by Dr. Orapint Jintasataporn and her team. Results of this trial were presented at the Aquaculture Europe 2023 conference by Dr. Hannele Kettunen, Hankkija Oy.
Progres® contains tall oil fatty acids (TOFA) with 9% natural coniferous resin acids. The anti-inflammatory and antimicrobial properties of coniferous rosin have been known in traditional medicine of the northern hemisphere for hundreds of years, and the effects have since been proven with scientific methods. When added to farm animal diets, Progres® improves animal performance and reduces the incidences of intestinal problems, thus greatly benefiting the economics of animal production
Research Study: Effect of Progres® on Asian Seabass performance
The present study was the first systematic approach to find out the potential of Progres® for farmed fish. It investigated the effects of dietary Progres® on the performance, immunological status and pathogen load of juvenile Asian seabass which were grown in typical freshwater conditions of Thailand (Figure 1).
Experimental Setup
A total of 300 juvenile Asian sea bass were allocated into 20 freshwater cages of 2 m3, 15 fish/cage, at a site with a known background challenge of the pathogenic, Gram-negative bacterium Aeromonas histolytica. The water was aerated to maintain DO >5 mg/l.
Feed was of commercial-type, with main ingredients of fishmeal, poultry meal, soybean meal and tapioca. It was amended with Progres® Liquid as follows:
The dietary treatments:
The fish were fed three times/day at 3-5% of body weight for 16 weeks. Fish weight, weight gain, feed intake and feed conversion ratio (FCR) were determined every 2 week, and the survival rate every 4 week.
Two fish/replicate were sampled for blood at 8- and 16-wk time points for determining the red blood cell (RBC) count, white blood cell (WBC) count, hemoglobin and haematocrit, and the concentrations of total serum protein and immunoglobulin M (IgM). The same fish were sampled for liver and intestinal contents for determining the number of Aeromonas spp. by plate culturing, using Aeromonas-selective media.
The study design was completely randomized. Data was analysed with one-way ANOVA, followed by Duncan’s Multiple Range Test, using p<0.05 as a limit for statistical significance.
Results and Key findings
Improved fish weight and weight gain: Progres® dose-dependently improved fish weight and weight gain from the 6-wk time point onwards (p<0.05); Figure 2. On week 8, the relative increase in fish weight was +5.9%, +10,0% and +16.2% for T2, T3 and T4, respectively.
Enhanced FCR: Progres® dose-dependently improved feed conversion ratio for weeks 6-14 (p<0.05); Figure 3.
Reduced fish mortality: Fish mortality tended to be reduced by Progres®; Figure 4.
Increased Haematocrit levels: Progres® significantly increased haematocrit on week 8; Figure 5, indicating an improved physiological status.
Boosted Immunoglobulin M (IgM) levels: Progres® significantly increased IgM both for week 3 and 16; Figure 6, suggesting a more efficient immune responses for Progres®-fed fish
Reducedpathogenic bacteria load: The Aeromonas load was reduced by Progres®; Figure 7, which implies that Progres improved the disease-resistance of the fish.
All results are summarized in Table 1.
Discussion and conclussion
Supplementing the diet of juvenile Asian seabass with Progres® Liquid promoted the growth performance, feed conversion and immunological capacity of the fish, and at the same time reduced the growth of Aeromonas spp. in the liver and intestinal tract.
Increased haematocrit and the trend towards higher serum protein levels in Progres®-supplemented groups indicates positive effects on the physiological status of the fish. The effects were dose-dependent, and the treatment with Progres® at 1.0 kg/ton gave the highest responses.
These results were in line with previous observations from studies with poultry and swine, in which dietary Progres® has shown consistently positive effects on performance, gastrointestinal microbiota and disease resistance.
In conclusion, Progres® has a high potential as a dietary strategy to improve the production performance and disease resistance of Asian seabass.
