Modern scientific research has shown that fat is not only the energy source of shrimp, but more importantly, it contains some fatty acids, and it is also a necessary nutrient for shrimp growth, immunity and development.
First, the classification of fatty acids, and their role.
For shrimp, fatty acids can be roughly divided into two types: one is a non-essential fatty acid, which can be synthesized by the shrimp itself, so it is called non-essential fatty acids. The other is essential fatty acids, the biggest characteristic of this type of fatty acids is that they cannot be synthesized by themselves or can be synthesized, but they cannot meet their own needs.
There are many essential fatty acids needed by shrimp, and the amount and proportion of essential fatty acids required are different according to different shrimp varieties and different sizes.
Among them, linolenic acid is one of the most important unsaturated fatty acids among essential fatty acids, and together with lectic acid, it is called the two important fatty acids of Penaeus vannamei.
Second, the role of linolenic acid in aquaculture.
1. Regulate immunity
Linolenic acid can promote the release of growth hormone, the growth of cells, increase the number of immunoglobulins in the blood, to achieve the effect of increasing the immunity of aquatic animals.
2. It is the main component of animal biofilm lipids
Linolenic acid plays a very critical role in most biofilms and plays a key role in maintaining cell balance in animals.
3. Regulate the metabolism of aquatic animals
Linolenic acid can inhibit the synthesis of cholesterol and stimulate enzymes related to animal metabolism such as lipase to improve the use and absorption of feed by animals and promote their growth rate.
There are many effects of linolenic acid, but there are still relatively few studies on shrimp farming. Therefore, today I would like to share with you a study that in the case of Penaeus vannamei infection with Enterosporidium (EHP), the addition of linolenic acid has an effect on the ability of Penaeus vannamei to resist EHP.
III. Research Design:
1. The specification of The penaeus vannamei of South American is 5g, and the water temperature is 26 degrees Celsius for experimentation.
2. Give EHP-infected Penaeus vannamei to 4 kinds of feed.
The first: feed without linolenic acid;
The second kind: feeding 1.2 g of linolenic acid / 1 kg of feed;
The third kind: feeding 2.4g of linolenic acid / 1kg of feed;
Fourth: 4.8 g of linolenic acid / 1 kg of feed.
Research findings and discussions
1, feeding four different kinds of feed, the results we found that the worst growth performance of Penaeus vannamei is the first (feed without linolenic acid), the third type of shrimp with the best growth performance (feeding 2.4g linolenic acid / 1kg feed).
2. When the number of EHPs was dissected and determined for all Penaeus vannamei, it was found that the first feed was fed the highest number of EHPs, and the third feed was fed the lowest number of EHPs. That is to say, linolenic acid can improve the ability of Penaeus vannamei to fight EHP.
3. Feed with linolenic acid can improve the expression of immune-related genes of Penaeus vannamei, so as to improve immunity, and improve the ability to resist oxidation, so as to achieve the ability to resist EHP.
V. Conclusion:
This study shows that linolenic acid may improve the immune system, antioxidant capacity, and ability to fight disease in Penaeus vannamei. At the same time, the optimal proportion of linolenic acid added to the feed is: 2.4 g of linolenic acid / 1 kg of feed.
Ultimately, this study provides a completely new way to improve the immunity of Penaeus vannamei and fight diseases, which can be used as a reference for farmers.
Source: No. 1 Aquatic Products