Which Fish Supplements Improve Growth Rate the Most?

The main criterion for commercial aquaculture performance is growth rate. Fast-growing stocks on farms, whether carp, tilapia, catfish or shrimp, directly influence production cycles, feed costs and, consequently, profitability. But even with many operations, there is still little emphasis on adding targeted supplements, even though they can be measured and offer an advantage.

This guide examines the categories of supplements with the best supporting evidence for their ability to increase growth rates of fish, their mode of action, and how to design a supplementation program that will really make a difference in your operation.

Understanding the Growth Rate in aquaculture is crucial.

Under optimum conditions, fish are very efficient at converting feed into body mass, but this is highly dependent on water quality, water temperature, and feed completeness. Nutrient deficiencies accumulate over a production cycle, leading to longer grow-out times, smaller even stock size, and increased feed expenses per kg of harvested fish.

That’s where growth based supplementation has come in handy in aquaculture. Farms that are aware of and try to correct the specific deficiency that is hindering the stock’s ability to grow further often reap returns that are well in excess of the value of the supplement.

Protein, amino acid supplements.

Fish growth is more influenced by the quality of protein than by its quantity. Fish also have specific essential amino acid requirements, such as lysine, methionine and threonine, and without providing these, even a high protein diet may not be effective.

1. Lysine and methionine: These are often the first limiting amino acids in plant aquafeed and supplementation with these has been proven in several studies to enhance growth rate and feed conversion efficiency.
2. Hydrolyzed protein supplements: Pre-digested protein sources have highly bioavailable amino acids which are more easily absorbed, especially in early life stages.

When using plant-based feed formulations for cost control, one of the best ways to fill the nutritional deficiency is to add in specific supplements such as amino acids.

Probiotics and Gut Health Supplements

In aquaculture nutrition, one of the most researched fields is gut health – and this has a direct impact on the efficiency of a fish’s digestion and absorption of nutrients, and hence on growth rate.

1. Probiotics strains: Probiotics containing beneficial bacteria like Bacillus and Lactobacillus species are found to improve the efficiency of digestion, and to compete with the pathogens, several studies have reported that these probiotics have a positive effect on growth and survival.
2. Prebiotics and synbiotics: These are compounds that promote growth of beneficial gut bacteria, which are often used in conjunction with probiotics for greater consistency during feed changes or during stressful periods, to keep a stable, supportive environment in the gut.

Gut health supplements boost nutrient digestibility of the feed provided, making them an excellent value for money as opposed to providing additional nutrients directly.

Vitamin and Mineral Premixes

A well formulated vitamin-mineral (VM) product is a key component in maximizing a fish’s growth potential. Protein and energy intake may be adequate, but their deficiencies can still slow growth.

1. Vitamin C: directly involved in the production of collagen and repair of tissues, both of which are important for sustained growth, especially in intensive farming.
2. Vitamin E and selenium: Protect against oxidative stress and support the immune system, indirectly support growth by reducing the metabolic strain associated with oxidative stress.
3. Phosphorus, calcium, zinc, and manganese: Essential for skeletal growth and enzyme activity that is important to biological processes related to growth.

The biggest yield gains may come from addressing these gaps, as is the case in intensive, high-density production systems.

Enzyme Supplements

Exogenous enzyme supplementation, in particular in aquafeed formulations that are rich in plant ingredients, which are less digestible for fish, has become a trend.

1. Phytase: Phosphorus making, which helps break down phosphorus locked in plant ingredients, making it more available.
2. Protease and amylase: Aid in digestion of protein and carbohydrates, enhancing digestibility, especially in young fish that have an underdeveloped digestive system.

For farms who are reducing their use of fish meal-based feeds, enzyme supplementation is particularly beneficial as it directly tackles digestibility issues with increased inclusion of plants.

Herbal and Phytogenic Growth Supplements

The nutritional status of the pig is a crucial determinant of both growth and well-being, and herbal and phytogenic preparations have become an important interest because of their potential to promote growth via enhancing digestion, immune activity and stress response.

1. Garlic and allicin extracts: Research into antimicrobial and immune supporting effects, indirect support for growth due to disease pressure reduction.
2. Turmeric and curcumin: They are believed to have anti-inflammatory and antioxidant effects, which may aid in maintaining metabolic efficiency.

In export aquaculture, where antibiotic-free, natural production claims are valuable to the market, as well as having a beneficial effect on production, herbal growth supplements are gaining in popularity.

How to choose the best supplement for your operation?

There are many options available and some of the important considerations for selecting the appropriate combination are: species nutrient needs, existing base feed nutrient contents, production levels, stock age, and base water quality – which can limit the effectiveness of even a good selection of a nutrient supplement.

Instead of attempting to use several of the overlapping products as a hedge, measuring growth before and after the use of a particular supplement and keeping track of how well the stock and system are doing will provide a much better idea of what is working for your stock and system. When working with a supplier that has a proven track record of providing nutrition specific to aquaculture, such as VarahVet, who has a dedicated aqua feed supplement category with species-specific formulations, there is a higher likelihood of improved growth results that can be measured and repeated versus those of generic, unbranded aqua feeds with unknown formulation.

Frequently Asked Questions

Q: How soon will growth rates improve following supplementation?

A: This depends on the type and species of the supplement, but many farms will see real results within 4-8 weeks of regular supplementation, especially with gut health or amino acid products.

Q: Can I take several different types of supplement, such as probiotics and enzymes at the same time?

A: Yes, some aquaculture nutrition programs use complementary ingredients, such as probiotics and enzyme supplementation, because they target different parts of the digestive processes and can be used in combination.

Q: Do herbal growth supplements work as well as amino acid or enzyme supplements?

A: There are various mechanisms by which herbal supplements act and they are mostly used for immune support and digestive support, along with, not in place of, the main nutrition supplementation of amino acids and enzymes.

Q: How do I know which nutritional gap is limiting my stock’s growth?

A: The best approach to determining what is truly limiting growth in a system is through feed formulation analysis, water quality testing, and monitoring growth rate and feed conversion ratio over time, preferably in conjunction with a qualified aquaculture nutritionist.