While fishmeal is one of the keys to the sustainable growth of the aquaculture industry. However, plant extract additives are always part of the potential proteome to replace fishmeal.
1. Protein management of aquatic feed
Often, farmers judge aquafeeds based solely on their crude protein content. However, crude protein analysis is mostly indirect (Kjeldahl method); At the same time, the nitrogen content in aquafeed samples often comes from many different sources, in addition to proteins such as phospholipids, chitin, biogenic amines, urea-formaldehyde, and other nitrogen-containing compounds.
Feed supplementation promotes average weight gain and improves FCR in Penaeus vannamei shrimp.
Secondly, proteins are made up of amino acids, and there are up to 20 types of amino acids. Feeds with a high crude protein content that does not guarantee a balance of essential amino acids will lead to poor growth and improved feed conversion (FCR). In addition, excess nitrogen can adversely affect water quality.
Finally, crude protein does not reflect the efficacy of nutrients on metabolic function and growth. While accurately determining the nutritional quality of an animal is complex, it makes sense to assess digestibility. In aquaculture, digestibility is usually calculated based on protein composition, selective amino acids, energy and phosphorus. Animal-derived phosphorus is easily digestible, unlike plant-based phosphorus, which is mainly in the form of phytic acid and is difficult to digest. In addition, the ability to digest fishmeal protein may be hampered due to the high ash content.
The processing method also has a significant impact. Soybeans contain many antinutrients, such as trypsin, which affect the activity of proteolytic enzymes. Boiling soybeans with heat can eliminate this factor. However, overheating can cause a Maillard reaction, which causes soybean lysine to bind to polysaccharides, making it difficult for the feed to absorb and reducing shrimp performance.
2. Feed additives can reduce fishmeal and protein
France nutrition company TECHNA has developed Economix products to reduce fishmeal and protein in aquafeeds. The main parameters evaluated by TECHNA included protein digestibility and protein utilization efficiency (PER); FCR, protein retention, feed efficiency, and intake.
Palatability and feed consumption are also taken into account when selecting raw materials. Since the aim is to reduce the cost of aquafeed, the cost of raw materials is carefully evaluated to find the optimal composition of the additive. A 2020 trial on the European barramundi (Dicentrarchus labrax) in SPAROS, Portugal, demonstrated the effectiveness of Economix in promoting digestion. Two trials of Penaeus vannamei were recently conducted in Indonesia and India. The aim of the experiment was not to improve shrimp production performance, but to reduce feed costs while maintaining the same yield.
In combination with dried palm oil:
In 2022, Dr. Romi Novriadi and colleagues from Jakarta University of Fisheries Technology, AUP Indonesia University of Technology, conducted a trial focusing on palm oil (PKM) because it is in abundant supply and competitively priced.
The trial consisted of a step-up of palm oil dry feed (2.5%; 6% and 9%) and control feeds. In addition, three additional products were formulated using the same PKM level, with Economix added at a dose of 2 kg/tonne. A 36 to 35 percent reduction in protein is expected, specifically 35.75 percent (control feed) and 34.08 percent (9% PKM + Economix diet). The fishmeal content decreased from 10% to 8%, and the content of poultry meal, soybean meal and corn starch decreased by 12% to 11%, respectively; 39.9% to 38.3% and 14.1% to 9.8%.
Experiments have shown that 9% PKM+Economix helps to reduce costs by 3.87%. In the seedling test, 0.7 g of Penaeus vannamei shrimp was placed into a 3 m² tank with a density of 50 PL/m², and each group was experimented for 5 times for 87 days. One-way ANOVA results showed that there was a difference in FCR, and the value was P<0.01. However, when performed with an analysis containing dried palm oil, the results showed that Economix had a clear effect in improving weight gain and enhancing lysozyme activity.
Economix supplementation promotes average weight gain and improves FCR. This result proves that Economix has improved the efficiency of shrimp farming. When combined with dried palm oil, this additive also helps to reduce the use of fishmeal and crude protein, thereby reducing overall feed costs.
When used in conjunction with DDGS:
The second trial was conducted at the Institute of Brackish Water Aquaculture (CIBA) in India under the supervision of Dr Ambasankar and colleagues. The group of experts compared the effects of four experimental and control feeds on shrimp growth. The first two experiments consisted of the Economix experiment and the negative control, with the same raw material as the control experiment, but with a 3.56% decrease in fishmeal rate (from 15.56% to 12%); corn gluten fell from 4% to 3.5%; In the meantime, add dried beans, peanut oil cakes, and sesame cakes to make up. Economix adds this additive at a dose of 2 kg/ton. These adjustments resulted in a decrease in protein content (theoretically rising from 36% to 35% and 36.5%; According to the results of the analysis from 35.7% and 35.18%).
The second modified formulation added 45% protein DDGS at a 3% ratio, including a negative control + DDGS and Economix + DDGS at a ratio of 2 kg Economix/ton. According to the results of the analysis, the protein values in these preparations continued to decline to the theoretical level of 34.5%, 35.69% and 35.7%, respectively. The results showed that the protein and amino acid content in the test feed formula was low; At the same time, the formulation cost of the Economix feed decreased by 1.62% and 2.49%, respectively, compared to the control feed.
In addition, the Economix supplement significantly improved FCR. The overall data showed that the growth of shrimp decreased by 0.2 and 0.23 g in the two negative control modes, respectively. In contrast, the shrimp group in Economix mode achieved higher growth (+0.1 g).
The above tests have proven that Economix can save on feed costs and does not negatively affect shrimp farming performance; At the same time, it improves the FCR and enhances the digestion of proteins, which improves the efficiency of feed utilization.