In the world of aquaculture, maximizing feed intake is crucial to ensure healthy and fast-growing shrimp. Traditionally, fish meal has been a key ingredient in shrimp diets due to its high palatability. However, recent trends towards plant-based protein alternatives for sustainability reasons may lead to a decrease in food acceptance and potentially hinder shrimp health.
Here’s where feed attractants come to the rescue! These special additives enhance the taste and aroma of shrimp feed, stimulating their appetite and encouraging them to eat more. But the benefits go beyond just taste.
A recent study by scientists from Guangdong Ocean University, the Aquatic Animals Precision Nutrition and High-Efficiency Feed Engineering Research Centre of Guangdong Province, the Key Laboratory of Aquatic, Livestock and Poultry Feed Science and Technology in South China, the Guangdong Provincial Key Lab of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, and Grobest Group Holdings Limited (CN) explored the effectiveness of various combinations of feed attractants on the growth, health, and gene expression of black tiger shrimp (Penaeus monodon).
Attractants enhance shrimp diets
Attractants, or feed attractants, are special ingredients added to shrimp feed that stimulate their appetite and make the food more appealing. These attractants work by mimicking the natural flavors and aromas that shrimp find irresistible, such as those found in fish and other marine species. They come in two main forms:
- Chemical attractants: Highly effective, but over time may lead to desensitization and reduced appetite.
- Natural attractants: Offer a synergistic effect, maintaining attraction while providing additional nutrients.
By incorporating the right combination of attractants, shrimp producers can overcome palatability challenges associated with plant-based diets, resulting in several benefits:
- Increased feed intake: Attractants lure shrimp to consume more food, translating into faster growth and overall better health.
- Improved nutrient utilization: When shrimp eat more, they absorb a greater amount of essential nutrients from the feed, maximizing its effectiveness.
- Enhanced gut health: Studies suggest that certain attractants can promote the development of a healthy gut microbiome in shrimp, stimulating their immune system and resilience to diseases.
The Science Behind Shrimp Feed Attractiveness
The study compared seven different diets:
- A positive control (P) made with commercial feed.
- A negative control (N) containing minimal attractants.
- Five diets (A-E) with an 8% total attractant content, each containing a combination of: Yeast extract, Squid viscera powder, Fish soluble, Squid paste, and Shrimp paste.
The results were promising:
- Improved growth: Compared to control diets, some combinations of attractants (specifically A and C) significantly enhanced weight gain, growth rate, and feed intake of the shrimp.
- Intestinal health improvement: Diets C, D, and E led to an increase in intestinal fold width, indicating a healthier intestinal structure.
- Gene expression boost: The study observed positive regulation of specific genes (pi3k, eif4ela, raptor, myd88, tor, imd, ror) associated with growth, immunity, and antioxidant activity. Particularly, diets A, C, D, and E showed this effect.
- Stress resilience: Diet D with a specific attractant combination improved the activity of antioxidant enzymes, potentially increasing shrimp resistance to stress.
Squid paste takes the spotlight
Interestingly, the study revealed that the amount of squid paste in the feed played a significant role. Higher levels of squid paste correlated with better weight gain and feed intake, while shrimp paste showed the opposite effect. Additionally, fish soluble appeared to increase feed intake, while yeast extract had a negative impact.
Conclusion: Attractants are beneficial for shrimp
This study highlights the significant benefits of incorporating well-chosen feed attractants into shrimp diets. Not only do they enhance palatability and feed intake, but they can also promote shrimp growth, intestinal health, and even improve stress resistance. By understanding the specific effects of different attractants, shrimp farmers can create optimized feed formulations for their specific needs.
Contact
Shiwei Xie
Laboratory of Aquatic Animal Nutrition and Feed, College of Fisheries, Guangdong Ocean University
Zhanjiang 524088, China.
Email: xswzsdx@163.com
Reference
Qu, K., He, G., Shi, M., Chen, X., Zhu, W., Chen, Z., Tan, B., & Xie, S. (2024). Effects of compound feed attractants on the growth rate, feed consumption, intestinal histology, protein synthesis, and immune response of black tiger shrimp (Penaeus monodon). Animal Feed Science and Technology, 311, 115952. https://doi.org/10.1016/j.anifeedsci.2024.115952
