What’s the key to a thriving fish farm? Feed! Feed costs make up 60-80% of the production cost, so it’s essential to maximize feed performance and minimize the expense. If you don’t, failure is certain. As such it is no surprise that most of the questions we get at the Planex Aquaculture Support Center are about feed and feeding practices. Therefore in this article we help you to maximise fish feed performance and get the basics right in 5 simple steps;
Step 1. Select the right feed
Step 2. Know your feeding plan
Step 3. Maximize the feed response of your fish
Step 4. Keep track of your feed
Step 5. Evaluate performance
Step 1. Select the right feed
In the wild, fish feed on micro aquatic plants and animals. In a (semi) intensive production environment, be it in cages or in ponds, these are not readily available in sufficient quantities, if at all. Instead it is the farmers responsibility to provide a nutritious diet for the fish, to make sure fish grow healthy and fast to the desired size.
There are many different feeds available. Some are farm made, some are produced in feed mills in Uganda and others are imported. Regardless of where and how it’s made, as a farmer there are 3 main criteria for good quality feed:
1. Nutrition profile; the feed needs to support health and growth
Nutrition is an incredibly extensive and complicated topic. A fish life cycle is divided into 5 distinct stages; fry, fingerling, juvenile, grower and finisher. At each stage the fish has specific nutritional needs in order to optimise its development at that time and balance the feeding cost. The table below presents a summary of the nutritional needs throughout the life of a Tilapia.
| Stage | Fish Weight (g) | Pellet size | Protein (%) | Lipids (%) |
| Fry | <1 | Powder | 50-45 | 5-7 |
| Fingerling | 1-10 | 0.5-1.5mm | 45-40 | 5-7 |
| Juvenile | 10-40 | 2.0-3.0mm | 40-35 | 5-7 |
| Grower | 40-200 | 3.0-4.0mm | 35-30 | 5-7 |
| Finisher | >200 | >5.5mm | 30-28 | 5-7 |
Protein is the main contributor to fish growth, whilst the carbohydrates and fat content provide the energy for the fish to swim. As the fish grows, its ability to convert protein to weight gain reduces and therefore the need for protein reduces. Not all protein sources however give the same benefits. Some proteins are easy to digest (e.g. animal protein) and others are more challenging (e.g. Plant protein). As such it is important to not only understand the nutrition profile of a feed but also have an understanding of the ingredients used. In addition to these macronutrients the fish also need micronutrients such as fiber, vitamins and minerals in order to be healthy.
2. Palatability; fish like to eat it
Fish love to eat things that taste and smell like the food that they eat in the wild. As such high quality fish feeds not only include the right ingredients for nutritional value but also to make the feed taste and smell like fish. This is something you can also easily check yourself. Does it smell like fresh fish? Does it seem to have an oily coating or is it bone dry? You can also taste it.
3. Easy to eat; the right size, color and texture of the pellet
Fish don’t chew their food. Therefore it is important that feed pellets are smooth in texture so that they can easily gulp them down. Ingredients also need to be finely ground to be easy to digest. A dark color feed is easy for the fish to spot as it floats on the water. Most important however is the pellet size. If it is too big it doesn’t fit in their mouth. If it is too small the fish needs to come up several times to get a mouth full. As such in addition to nutrition by growth stage, pellet sizes are tailored to the size of the fish’s mouth at that particular stage as well. See table 1. Furthermore feed needs to have water stability, this means it needs to float on the water, and not disintegrate quickly once it is in the water. With good water stability it makes it easier for the fish to eat the feed efficiently.
Suitability of feed
Aside from feed quality the actual feed performance will also depend on your specific situation. You need to consider for example your species of fish, type of aquaculture system, growth stage, and the cost of feed. As such it is important to understand your fish and your farm. What works for a big professional cage fish farm might not give the same results for a small starting pond farmer.
Ensure the feed is available and cost effective. The best feed won’t benefit your farm if you can’t get it. Cheap feed may seem advantageous, but if it takes more time and quantity for the fish to reach harvest size, you’ll suffer losses. Expensive feed could make the fish grow quickly, but if the feed cost outweighs the sale price, it’s not beneficial. Balance and knowledge of feed needs throughout the production cycle is essential.
There are several good quality feeds out there from various suppliers. Any good supplier can provide you with product documents including specification sheets and explain the details to you. Once you identify your preferred feed and its supplier look for at least 2 alternatives to have a backup plan ready. Also, just to be sure, always keep a buffer stock of feed for maybe a week or more in your storeroom.
Step 2. Know your feeding plan
Once you have fish in the water you have to feed them. If you don’t they will stop growing, develop health issues, be off less quality even when they mature, and consistent lack of feeding constitutes animal cruelty. Consequently we highly recommend that before you stock, you understand your feed requirements for the full production cycle. You can record this in a feeding plan so that you can organise yourself accordingly and have an easy reference point to check back at any time.
The feeding plan helps you plan both the amount of feed that you should be feeding per day and at what times you want to do so. It also gives you an overview of the total production cycle. As such it is also a great reference point to have to check your performance against.
Feed required per day
Feed per day tells you much feed you need for your fish on a specific day. Often production units are of different capacity and have a different stocking density. Therefore it is good practice to calculate the feed required per day per cage or pond so that you know how much you should feed each and draft a feeding plan for each unit.
You calculate the feed required per day as follows.
- Obtain the ABW (Average Body Weight) (grams) of your fish at stocking by sampling or from your fingerling supplier. This helps you identify the right type of feed and the right size pellet.
- Find the recommended Feeding Rate (FR) for the ABW size fish and feed type from the feeding table from your supplier
- Know the number of Fish in the production unit
- With the above information available you calculate the daily feed requirement with the formula below.
| Daily feed required = ABW × FR × Fish No. |
Feed per production cycle
As discussed before, it is important to ensure the feed fed is suitable to the life stage of the fish to maximize performance. Not only do nutrition profiles differ but so do feed prices. Therefore, when calculating feed needed for the whole production cycle and its estimated cost there are 2 options. First is the overall amount of feed needed in kilograms or metric tonnes. Second is a detailed breakdown of exactly how much of each type of feed is required.
A key metric is the Feed Conversion Ratio. The FCR is calculated by dividing the total amount of feed fed to a fish by the total weight gain of that same fish. In other words, the FCR is the amount of feed required to make 1 kilogram of fish. Using the FCR you calculate the overall needed amount of feed in 5 steps:
- Calculate the weight gain required: ABW at harvest – ABW at stocking = weight gain. For example you harvest at 500 grams and stock at 1 gram. Then the desired weight gain per fish is 500 – 1 = 499 grams.
- Ascertain the average FCR from the feeding table from your feed supplier.
- Identify the number of fish in the production unit.
- Estimate the number of mortalities that you expect over the course of the production cycle.
- With the information gathered, you calculate the overall needed amount of feed with the formula below.
| Feed per cycle = FCR × body weight gain × ( number of fish – expected mortalities) |
For a detailed breakdown of the feed required in a production cycle you need to use this formula for each specific growth stage. You can download a feed calculator here that also helps you estimate the cost of the feed!
Step 3. Maximize feed response of the fish
In order to maximize feed performance it is all about optimizing the fish’ feed response and minimizing feed waste. The feed response is the urge of the fish to eat when you feed them. Feeding practices therefore are a set of measures to make sure that the fish eat as much as possible when you feed them whilst making sure that you don’t over feed. Best feeding practices include:
1. Feed on schedule
It is advisable to make a feeding schedule per production unit, to feed at the same times each day. This trains fish to eat at specific times. Appropriate intervals range from 8 to 2 times a day and depend on the growth stage of the fish, the weather and your water quality. Usually fish are more responsive when it is warmer therefore they tend to eat more in the afternoon.
2. Repeat: Wear the same color, feed from the same location, make the same calling sound
Fish can easily be trained to recognize that it is time to feed, and be called to the feeding location. This can be done by feeding at the same place, by having the feeder wear the same color clothing and by making a distinct sound to call the fish. This will trigger the fish to come to eat at the right place at the right time.
3. Throw the feed in the water with a sweeping motion
This has 2 benefits. Firstly the sounds produced by the pellets hitting the water lets the fish know there is feed in the water and calls them over. In addition it spreads out the feed over a large area. This avoids too much competition between the fish in a small area which would require them to expel too much energy to feed and can cause injuries to the fish.
4. Feed by response
Once you feed at specific times, fish should be hungry by the time you feed them. When they take more than 5 minutes to consume the feed you put in the water they are satisfied and you can stop feeding until the next time slot. Whilst feeding it is therefore important to keep a keen eye on the fish and note their behavior. Some days they might eat more than others, or there might be other changes. Keep notes of the feeding behavior and the environment in the feeding log of the production unit.
5. Feed as planned: the right feed type and quantity
For each production unit you know the feed type and quantity required per day from your feeding plan. Ensure that this plan is followed. Based on the feeding response you can divide it to the different time slots. For example if total feed requirement for pond 1 is 100 kg and you feed 4 times a day you might feed 10kg in the morning at 8am, 15kg at 12am, 35kg at 3pm and the balance at 5pm. How much you feed when is not so important as long as you don’t feed more then the total in a day, and the fish eat all the feed that you throw in the water at a specific time.
Step 4. Keep track of your feed and feeding
Consistent record keeping gives you insight into what has been happening on your farm and it makes it easier to identify and solve any problems that may arise. Keep the documents fast and easy to use. A basic form that is consistently used, gives you more information than a highly detailed form with great questions that is only used once. To keep track of your feed management you want to have the following in place:
- Feeding guide from your supplier(s)
- Feeding plan per production unit
- Feeding log per production unit
- Weekly feed report
- Feed purchase log
Download our free formats to help you get started!
Step 5. Assess feed performance
Feed performance is evidenced by the growth of the fish. As such the only way to assess performance is through regular sampling. When sampling, keep records including weight, length and the number of fish. Do this at least five times over the course of a production cycle. Combined with the feeding log it enables you to calculate your actual FCR and also gives a clear estimate of the number of fish in the production unit. The lower the FCR the better the feed performance is.
FCR ratios vary throughout the growth stages. Over a whole production cycle an FCR of between 1-2 can be in the acceptable range where 1 represents the best and 2 the worst. By tracking the FCR per production unit and per growth stage of the fish consistently you build up your own reference points. You can also ask your supplier for their FCR benchmarks as a reference point. By comparing an FCR to a relevant benchmark you can easily detect problems and progress. If your usual FCR at the growth out stage is 1.7 and now you have implemented the feeding best practices set out in step 3 and your FCR drops to 1.6 you know you are on the right track. Conversely if you suddenly have a cage where the FCR is 1.9 you know that there is a problem to address. Knowledge is power!
You see that despite all the technical talk about feeding your fish, it is not that difficult to get the basics right by following these 5 simple steps. Have you put the basics in place and want to take it to the next level? Or do you need help to get the foundation right? If you have any questions about feed or feeding, or anything else related to aquaculture, contact our support team today!
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The Planex Aquaculture Support Center is part of the Planex Foundation and Planex Group of Companies U Ltd. Planex is the exclusive distributor of ADM Aqua feeds in East Africa.
