# Feed Budgeting for Aquaculture: Calculating Daily Rations and Costs ## Key Takeaways - Feed constitutes the largest operational expense in aquaculture (40-60%), necessitating precise daily ration calculations to optimize growth and minimize waste. Underfeeding slows growth and extends market time, while overfeeding degrades water quality and converts feed to ammonia. - Daily feed rations are dynamic, calculated by multiplying estimated current biomass by a species- and temperature-dependent feeding rate percentage, which must be recalculated at least weekly as fish grow and mortality occurs. - Feed Conversion Ratio (FCR) is a critical metric for profitability, representing the feed input required per unit of fish weight gain; a 0.1 improvement in FCR can significantly impact profit margins more than minor feed price fluctuations. - Water temperature is a primary driver of feed intake, with warmwater species doubling consumption for every 5-6°C rise within their optimal range, necessitating temperature-specific feeding rate adjustments. - Unexplained drops in feed intake are often the earliest indicator of disease or poor water quality (low dissolved oxygen, high ammonia/nitrite), requiring immediate investigation and potential ration reduction. - A robust feed budget projects monthly feed needs to secure favorable pricing, manage storage logistics, and avoid costly emergency purchases, with feed cost per kilogram of fish produced being the definitive profitability metric. --- Feed is the single largest operating expense on most aquaculture farms, often consuming 40 to 60 percent of total production costs. Getting the daily ration wrong in either direction carries real consequences. Underfeeding slows growth, extends time to market, and wastes the fixed costs of labor and facility operation. Overfeeding pollutes the water, stresses the fish, and converts expensive feed into ammonia instead of fillet. This guide walks through the full process of building a working feed budget, from understanding the biological drivers of intake to calculating daily rations by hand, projecting costs across a full production cycle, and keeping the records that let you adjust before problems compound. It is written for farm owners, production managers, and aquaculture students who need a practical planning tool, not a theoretical overview. The methods here apply to pond, tank, cage, and raceway systems, with notes on where species differences matter. ## At a Glance - Daily feed ration is calculated from estimated biomass on hand multiplied by a feeding rate percentage that changes with water temperature, fish size, and health. - The most common budget error is using initial stocking weight for the whole grow-out period. Ration must be recalculated at least weekly as fish grow. - [Feed conversion ratio](/knowledge/animal-farming/poultry/feed-conversion-ratio-measuring-improving-poultry-efficiency) (FCR) is the bridge between feed input and production cost. A 0.1 improvement in FCR can change profit per ton more than a small change in feed price. - A complete feed budget projects feed purchases by month so you can lock in prices, arrange storage, and avoid emergency purchases at retail rates. - Feed cost per kilogram of fish produced, not feed cost per bag, is the number that matters for farm profitability. - Water temperature is the master variable. Most warmwater fish double their feed intake for every 5 to 6 degrees Celsius rise within their optimal range. - Recordkeeping should tie feed delivery to mortality events and water quality changes. Unexplained drops in feed intake are often the first sign of disease. - A feed budget is a living document. Revisit it every 7 to 14 days and adjust for observed growth, mortality, and feed response. ## Why Feed Budgeting Fails on Working Farms Most feed budget problems are not caused by bad math. They are caused by bad inputs. The formula for a daily ration is simple, but the numbers you feed into it are estimates, and estimates carry error. Understanding where that error enters the system is the first step to controlling it. ### The Biomass Estimation Problem The core of any feed budget is knowing how many kilograms of fish you have in the water. You cannot weigh the fish directly, so you estimate. The estimate starts with the number of fish stocked and the average weight of a sample, then multiplies by a survival rate. Each of those numbers carries uncertainty. Stocking counts are usually accurate if you count or weigh fish at delivery, but mortality is the wildcard. A farm that stocks 50,000 fingerlings and assumes 90 percent survival has 45,000 fish in the budget. If actual survival is only 80 percent, the budget overestimates biomass by more than 11 percent, and the farm overfeeds by that same margin. Overfeeding at that level for a month can degrade water quality enough to cause additional mortality, creating a downward spiral. The fix is not to abandon the estimate but to ground it in regular sampling. Weigh a sample of 30 to 50 fish every 7 to 14 days. Track mortality daily. Recalculate biomass after every sample event. The budget is only as good as the biomass number, and the biomass number is only as good as your sampling discipline. ### Fixed Ration Versus Variable Ration A second common failure is treating the daily ration as a fixed number. Fish grow, so biomass grows, so the ration must grow. A 10 gram fish at 5 percent body weight per day eats 0.5 grams. A 100 gram fish at 3 percent eats 3 grams. If you stock 10,000 fish and feed at the initial rate for the entire grow-out, you will underfeed catastrophically by the end of the cycle. Some farmers try to solve this by feeding to satiation, which means offering feed until the fish stop eating. This works on small farms with trained staff, but it has a serious weakness. Fish do not always stop eating because they are full. They stop because water quality is poor, oxygen is low, or disease is setting in. Feeding to satiation can hide those problems and can also lead to chronic overfeeding if the fish are active but inefficient at converting feed. The better approach is a calculated ration adjusted by observed response. Set the target ration from the formula, offer that amount, and watch how completely the fish consume it. If they clean up all feed within 15 to 20 minutes, consider a small increase. If feed remains after 30 minutes, cut back. This combines the discipline of a budget with the feedback of observation. ### Ignoring Water Temperature Feed intake is temperature driven. For warmwater species like tilapia, catfish, and carp, metabolic rate rises with temperature within their tolerance range. A pond at 18 degrees Celsius supports a feeding rate of maybe 1 percent of body weight per day. The same fish at 28 degrees Celsius will eat 3 to 4 percent. Farmers who feed the same amount year round either waste feed in summer or starve fish in spring and fall. The relationship is not linear, and it is not identical across species. Coldwater species like trout and salmon have optimal feeding temperatures in the 10 to 15 degree range and stop feeding altogether above 20 degrees. Warmwater species stop feeding below about 15 degrees and above about 35 degrees. Your feed budget must be built around the temperature curve for your species and your climate. ### The Cost of Emergency Purchases Feed budgeting is not only about how much to feed. It is also about when to buy. Feed prices fluctuate with commodity markets, and buying in small quantities at short notice almost always costs more per ton than contracting ahead. A farm that plans its monthly feed needs can lock in prices during seasonal lows, buy in bulk to earn volume discounts, and avoid the premium prices that feed mills charge for small emergency orders. Storage is part of this equation. Feed that sits in a hot, humid shed loses nutritional quality and can develop mold or insect infestation. A budget that calls for buying six months of feed at once only makes sense if you have proper storage. Otherwise, plan purchases in 4 to 6 week increments and coordinate with the feed mill delivery schedule. ## Building the Daily Ration Formula The daily ration is the amount of feed offered on a single day, expressed in kilograms or pounds. The formula is straightforward: Daily Ration (kg) = Estimated Biomass (kg) x Feeding Rate (percent of body weight per day) The feeding rate is the percentage of total body weight that the fish will consume in one day. A 2 percent feeding rate on 1,000 kilograms of fish means you offer 20 kilograms of feed per day. The skill in feed budgeting is choosing the right feeding rate and keeping the biomass estimate current. Both change through the production cycle. ### Step 1: Estimate Current Biomass Biomass is the total weight of all fish in the system. Calculate it as: Biomass (kg) = Number of Fish Alive x Average Weight per Fish (kg) The number of fish alive comes from your stocking count minus observed mortality. The average weight comes from sampling. For a new stocking, the average weight is the delivery weight from the hatchery. Weigh a sample of 20 to 30 fish at stocking to confirm the hatchery weight. Do not trust the invoice alone. Fish lose weight during transport, and the actual delivered weight may be lower than the billed weight. For an ongoing grow-out, sample at least 30 fish from multiple locations in the pond or tank. Weigh them individually on a sensitive scale. Calculate the average. If the fish are large, sample more fish because individual variation is greater. ### Step 2: Select the Feeding Rate The feeding rate depends on species, water temperature, fish size, and health status. Table 1 gives general ranges for common aquaculture species. **Table 1: Typical Feeding Rates by Species and Temperature** | Species | Temperature Range (C) | Feeding Rate (% body weight/day) | |---|---|---| | Tilapia | 22 to 30 | 2.0 to 4.0 | | Channel catfish | 24 to 30 | 2.0 to 3.5 | | Rainbow trout | 10 to 15 | 1.5 to 3.0 | | Common carp | 22 to 28 | 2.0 to 4.0 | | Pacific white shrimp | 26 to 32 | 3.0 to 8.0 | | Atlantic salmon | 8 to 14 | 1.0 to 2.0 | These ranges assume healthy fish in good water quality. Reduce the rate by 30 to 50 percent when temperatures are at the low end of the range, when dissolved oxygen is below 5 mg/L, or when fish are recovering from handling or disease. Fish size also matters. Small fish have higher metabolic rates per unit of body weight and eat a higher percentage. A 5 gram tilapia fingerling may eat 6 to 8 percent of its body weight daily. A 500 gram market fish eats 1.5 to 2 percent. Feeding rate tables from feed companies and extension services usually provide size-specific values. Use those when available. ### Step 3: Calculate the Ration Multiply biomass by the feeding rate. Here is a worked example. A farmer has 12,000 tilapia with an estimated survival of 90 percent from a stocking of 13,333. Sampling shows an average weight of 150 grams, or 0.15 kilograms. Biomass = 12,000 x 0.15 = 1,800 kilograms Water temperature is 28 degrees Celsius. The feeding rate for 150 gram tilapia at 28 degrees is 3.0 percent. Daily Ration = 1,800 x 0.03 = 54 kilograms of feed per day Check the math: 1,800 kilograms of fish eating 3 percent of their body weight consumes 54 kilograms. That is the starting point for the day. ### Step 4: Adjust for Observed Response The calculated ration is a target, not a command. Observe how the fish respond at feeding time. If they consume all feed within 15 minutes and still show active feeding behavior, increase the next day's ration by 5 percent. If feed remains after 30 minutes, decrease by 5 to 10 percent. If feed remains consistently, check water quality and fish health before blaming the ration. This adjustment loop is the difference between a budget on paper and a budget that works in the water. The formula gives you a starting number. Observation refines it. ### Step 5: Recalculate Weekly Biomass changes every day as fish grow and as mortality occurs. Recalculate the ration at least weekly. If you are in a rapid growth phase, recalculate every 5 to 7 days. If growth has slowed due to cold water, every 14 days is acceptable. To recalculate, you need a new average weight. Sample fish, compute the new average, multiply by the current number of fish, and apply the feeding rate for the new average size and current temperature. Do not skip the sampling step. Guessing that fish gained 10 percent since last week is how budgets drift. A 30 fish sample takes 20 minutes and removes most of the guesswork. ## [Feed Conversion Ratio](/knowledge/animal-farming/poultry/feed-conversion-ratio-measuring-improving-poultry-efficiency) and Cost Projection The daily ration tells you how much to feed today. The feed conversion ratio tells you how efficiently that feed becomes fish. FCR is the ratio of feed fed to weight gained: FCR = Total Feed Fed (kg) / Total Weight Gain (kg) An FCR of 1.5 means 1.5 kilograms of feed produced 1 kilogram of fish gain. Lower is better. Tilapia and catfish typically run 1.4 to 1.8. Trout and salmon run 1.0 to 1.3. Shrimp often run 1.5 to 2.5 depending on system and management. ### Why FCR Matters More Than Feed Price Consider two feed options. Feed A costs $600 per ton with an FCR of 1.6. Feed B costs $650 per ton with an FCR of 1.4. To produce 1,000 kilograms of fish: Feed A cost = 1,000 x 1.6 x $0.60 per kg = $960 Feed B cost = 1,000 x 1.4 x $0.65 per kg = $910 The more expensive feed is cheaper per kilogram of fish produced. This is why feed budgeting must work in cost per kilogram of production, not cost per bag. The formula for feed cost per kilogram of fish produced is: Feed Cost per kg Fish = Feed Price per kg x FCR Track this number through the production cycle. It is the single most useful metric for evaluating feed purchasing decisions. ### Projecting Feed Needs for the Full Cycle To build a full cycle feed budget, project the feeding rate and biomass forward week by week. Start with the current biomass and the expected growth rate. Growth rate is the daily weight gain per fish, which you can estimate from historical records or from the feed company growth tables for your species and temperature. A simplified projection table looks like this: **Table 2: Sample Feed Budget Projection for 10,000 Tilapia** | Week | Avg Weight (g) | Biomass (kg) | Feeding Rate (%) | Daily Ration (kg) | Weekly Feed (kg) | |---|---|---|---|---|---| | 1 | 20 | 200 | 5.0 | 10.0 | 70 | | 2 | 25 | 250 | 4.8 | 12.0 | 84 | | 3 | 31 | 310 | 4.6 | 14.3 | 100 | | 4 | 38 | 380 | 4.4 | 16.7 | 117 | | 5 | 46 | 460 | 4.2 | 19.3 | 135 | The growth assumption drives the whole table. If actual growth is slower than projected, the biomass will be lower than the table shows, and feeding at the projected rate will overfeed. Reconcile the projection with actual sampling data every week. ### Building the Cost Projection Once the feed quantity projection is complete, multiply by the feed price to get the cost projection. Use the delivered price per ton, including freight and any taxes. Break the projection into monthly totals so you can plan cash flow and purchasing. For example, if the weekly feed projection totals 4,000 kilograms in month three and feed costs $650 per ton delivered, the month three feed cost is 4,000 x $0.65 = $2,600. Sum across months for the full cycle feed cost. Compare this to the expected revenue from the harvest to check that the operation is viable before you commit to the cycle. If feed cost alone consumes more than 60 percent of projected revenue, the cycle is likely to lose money unless you can improve FCR or negotiate a better feed price. ## Feeding Methods and Their Effect on the Budget How you deliver feed affects how much is wasted and therefore the real cost of the ration. The budget assumes the fish eat everything you offer. In practice, feed losses occur through poor distribution, overfeeding, and feed that sinks into the mud or passes through the cage mesh. ### Hand Feeding Versus Automatic Feeders Hand feeding gives you the most control and the best observation of fish response. A trained feeder can adjust the ration in real time and can spot health problems early. The cost is labor. On a large farm, hand feeding every pond or tank can consume several hours per day. Automatic feeders deliver feed on a timer or on demand. They reduce labor and can spread feed over many small meals, which improves feed efficiency for some species. The risk is that a feeder malfunction can dump an entire hopper of feed into the water, and nobody notices until the water quality crashes. Check automatic feeders daily and calibrate them weekly. ### Feeding Frequency Small fish benefit from multiple daily feedings because their stomach capacity is small relative to their metabolic demand. A 5 gram fingerling fed once daily cannot physically consume its full daily ration in one meal. Feed it three to four times per day. Larger fish can handle one or two feedings daily. More frequent feeding generally improves FCR because the fish convert feed more efficiently when meals are smaller. The tradeoff is labor and equipment cost. A farm that feeds twice daily instead of once may see a 5 to 10 percent improvement in FCR, which can pay for the extra labor. ### Floating Versus Sinking Feed Floating feed lets you observe feeding activity directly. You can see whether fish are coming to the surface and how aggressively they eat. This makes ration adjustment easier. Floating feed also stays available longer, giving slower fish a chance to eat. Sinking feed is often cheaper per ton and is necessary for some species like shrimp and bottom feeding fish. The disadvantage is that you cannot see consumption, and uneaten feed falls into the sediment where it decomposes and drives up oxygen demand. If you use sinking feed, the feed budget must include a waste allowance of 5 to 10 percent to account for unavoidable losses. ## Water Quality and Its Effect on Feed Intake Feed budgeting cannot ignore water quality because water quality directly controls how much the fish will eat and how efficiently they convert feed. The budget assumes the fish are healthy and the water is within their tolerance range. When water quality degrades, the ration must be cut regardless of what the formula says. ### Dissolved Oxygen Dissolved oxygen is the most critical water quality variable for feed intake. Fish need oxygen to metabolize feed. When oxygen is low, they stop eating. The practical rule is to feed only when dissolved oxygen is above 5 mg/L for warmwater species and above 7 mg/L for coldwater species. Feeding during low oxygen conditions wastes feed and adds to the oxygen demand at exactly the wrong time. In pond systems, the lowest oxygen levels occur in the early morning before photosynthesis begins. Feed in the late morning or early afternoon when oxygen is rising. In flow through raceways and recirculating systems, oxygen is more stable, but you should still check levels before feeding. ### Ammonia and Nitrite Feed is the source of most nitrogenous waste in aquaculture systems. When you feed, the fish excrete ammonia. In systems with limited water exchange, ammonia accumulates and suppresses feed intake. The budget must account for the carrying capacity of the system. If ammonia levels are rising, cut the ration by 20 to 30 percent until the system recovers. High nitrite levels are a particular problem in recirculating systems and in ponds with heavy organic loads. Nitrite binds to hemoglobin and reduces oxygen transport, which reduces feed intake even when dissolved oxygen is adequate. Test nitrite regularly and reduce feeding when levels approach the tolerance threshold for your species. ### Temperature Extremes Feeding at the edges of the temperature tolerance range is inefficient. Warmwater fish at 15 degrees Celsius have very low metabolic rates and convert feed poorly. Feeding them at 2 percent of body weight in 15 degree water produces mostly waste. Cut the ration to 0.5 to 1 percent and accept slow growth until temperatures rise. Coldwater fish face the opposite problem. Trout stop feeding above 20 degrees and become stressed. If water temperature exceeds the species optimum, cut the ration by half or stop feeding entirely until conditions improve. ### The Oxygen Debt of Feeding Every kilogram of feed creates a biochemical oxygen demand in the water. The fish consume oxygen to digest the feed, and bacteria consume oxygen to break down the waste products. A heavy feeding event can drop dissolved oxygen by 1 to 2 mg/L within a few hours. In ponds with marginal oxygen levels, this can push fish into stress or mortality. Budget for this by avoiding large single feedings in systems with limited aeration. Split the daily ration into two or three feedings spaced through the day. Run aeration during and after feeding. If you have aeration capacity, time the feeding to coincide with peak oxygen production from photosynthesis. ## Common Feed Budgeting Mistakes Farmers make the same feed budgeting errors repeatedly. Recognizing them early can save significant money and prevent crop loss. ### Mistake 1: Using Initial Stocking Weight for the Whole Cycle This is the most common and most costly error. A farmer stocks 10,000 fingerlings at 20 grams, calculates a ration based on 200 kilograms of biomass, and keeps feeding that amount for months. By week eight, the fish weigh 150 grams and the true biomass is 1,500 kilograms. The fish are being fed at about 13 percent of their actual requirement. Growth stalls, time to market extends, and the farm loses money on every day of extended grow-out. The fix is disciplined weekly recalculations. Put a calendar reminder. Sample fish every 7 to 14 days. Recalculate the ration every time. ### Mistake 2: Feeding Through a Disease Outbreak When fish are sick, they stop eating. Forcing feed on sick fish wastes money and degrades water quality. The common instinct is to keep feeding because the fish need nutrition to recover. In most cases, the opposite is true. Reduce the ration by 50 percent or stop feeding entirely for a few days when you suspect disease. Resume feeding gradually as the fish show interest. If feed intake drops suddenly with no change in temperature or water quality, treat it as an early warning sign. Check for clinical signs of disease. Check dissolved oxygen and ammonia. Check for dead or moribund fish. A sudden drop in feed intake is often the first observable sign of a health problem. ### Mistake 3: Ignoring Feed Storage Losses Feed that sits in a hot shed for three months loses vitamin potency and can develop rancidity. Feed that gets wet grows mold. Fish eat less of degraded feed, FCR worsens, and the budget numbers no longer hold. Store feed in a cool, dry, ventilated area. Use older stock first. Do not buy more than you can store properly. The practical rule is to buy feed in 4 to 6 week increments unless you have climate controlled storage. This costs a little more per ton but avoids the hidden losses of degraded feed. ### Mistake 4: Confusing Feed Price with Feed Cost A farmer who buys the cheapest feed per ton may be paying the most per kilogram of fish produced. The budget must track feed cost per kilogram of gain, not feed cost per bag. A feed that costs 10 percent more but delivers a 10 percent better FCR is a wash on cost and may produce better growth and health. Compare feeds on cost per kilogram of fish produced, using the expected FCR for each feed in your system. This requires trusting the feed company FCR data or running your own small scale comparison. ### Mistake 5: Not Accounting for Mortality The budget assumes a certain survival rate. If mortality is higher than assumed, the biomass is lower and the ration should be lower. Farmers who keep feeding at the original rate after a mortality event are feeding dead fish. Count mortalities daily. Adjust the biomass estimate and the ration accordingly. ### Mistake 6: Feeding on a Fixed Schedule Regardless of Conditions A budget is a guide, not a command. The ration must flex with conditions. Do not feed a full ration during a cold front, after a chemical treatment, or when oxygen is low. The best farmers have a mental rule: when in doubt, cut the ration by 25 percent and observe. ## Monitoring and Recordkeeping for Feed Management The feed budget only works if you track what actually happens against what you planned. This requires a simple, consistent recordkeeping system. ### The Daily Feed Log Record the following for every feeding event: - Date and time of feeding - Pond or tank identification - Feed type and lot number - Amount of feed offered in kilograms - Estimated amount consumed - Water temperature at feeding time - Dissolved oxygen at feeding time - Observed feeding behavior (aggressive, normal, sluggish, no response) - Any unusual observations (dead fish, lethargy, abnormal swimming) This log is the raw data for all feed management decisions. It takes 5 minutes per pond per day. It is the most valuable record on the farm. ### The Weekly Biomass and Ration Summary Once per week, summarize the daily logs into a weekly record: - Total feed fed for the week - Average water temperature - Mortality count and cumulative survival - New average weight from sampling - Recalculated biomass - Recalculated daily ration - Feed cost for the week Compare the actual feed used to the budget projection. If you are feeding more than projected, identify why. If less, identify why. The variance is information, not a problem to ignore. ### Tracking FCR Through the Cycle Calculate FCR at each sampling event. Use the formula: FCR = Total Feed Fed Since Last Sample / Weight Gain Since Last Sample Track FCR over time. A rising FCR through the grow-out cycle is normal because larger fish convert feed less efficiently. A sudden jump in FCR with no change in fish size suggests feed waste, water quality problems, or disease. ### The Feed Inventory Record Track feed on hand, feed received, and feed used. This record prevents running out of feed at a critical growth period and prevents feed from sitting too long in storage. The formula is: Closing Inventory = Opening Inventory + Feed Received - Feed Fed Reconcile this record monthly. If the calculated closing inventory does not match the physical inventory, investigate theft, spoilage, or recording errors. ## When to Call a Veterinarian or Extension Agent Most feed budgeting problems are management problems that you can solve with better data and better discipline. Some problems require professional help. Know the difference. ### Call a Veterinarian When Feed Intake Drops Suddenly A sudden, unexplained drop in feed intake across multiple ponds or tanks is a red flag for disease. If fish are also showing clinical signs such as lethargy, gasping at the surface, unusual swimming patterns, or visible lesions, contact an aquatic veterinarian promptly. Do not wait for mortality to confirm the problem. The veterinarian can perform a necropsy, identify the pathogen, and recommend treatment. Early intervention with disease is almost always cheaper than the alternative. A veterinarian can also help you rule out non infectious causes such as toxin exposure or nutritional deficiency. ### Call an Extension Agent for System Level Problems Your local aquaculture extension agent can help with feed budgeting questions, water quality troubleshooting, and production planning. Extension agents have access to regional growth data, feed company performance records, and economic models that can improve your budget assumptions. Extension agents are especially useful when you are starting a new species, expanding production, or considering a major system change. They can connect you with other farmers who have faced the same challenges and with research results from your region. ### Call for Help When FCR Worsens Without Explanation If your feed records show a steady FCR of 1.5 and it suddenly moves to 2.0 with no change in fish size, temperature, or feed type, something is wrong. It could be feed quality, water quality, disease, or a measurement error. A professional can help you identify the cause before it costs you an entire production cycle. ## Frequently Asked Questions ### How often should I recalculate my daily feed ration? Recalculate at least every 7 days during the active growth season. If water temperature is changing rapidly in spring or fall, recalculate every 5 days. If fish are small and growing quickly, recalculate weekly. If fish are large and growth has slowed, every 14 days is acceptable. The key is to tie recalculation to actual sampling data, not to a calendar guess. ### What is a good feed conversion ratio for tilapia? Well managed tilapia farms achieve FCR values of 1.4 to 1.7. This assumes good water quality, appropriate feeding rates, and a quality feed. Poor management can push FCR above 2.0, which adds significantly to production cost. If your tilapia FCR is consistently above 1.8, examine your feeding practices, water quality, and feed storage. ### How do I calculate feed cost per kilogram of fish produced? Multiply the feed price per kilogram by the FCR. If feed costs $0.65 per kilogram and your FCR is 1.6, the feed cost per kilogram of fish produced is $1.04. This number should be tracked for every crop. It is the most direct measure of feeding efficiency and feed purchasing decisions. ### Should I stop feeding when water temperature drops? Do not stop feeding entirely unless temperatures are at the lethal limit for your species. Instead, reduce the ration to match the reduced metabolic rate. Warmwater fish at 15 to 18 degrees Celsius may eat only 0.5 to 1 percent of body weight daily. At those temperatures, feed a high quality, highly digestible feed and feed only on warm afternoons. Coldwater fish have different temperature optima and may feed well at temperatures that stop warmwater fish. ### How much feed should I buy at one time? Buy only what you can store properly. Feed stored in a clean, dry, ventilated area with temperatures below 25 degrees Celsius can maintain quality for 6 to 8 weeks. In hot, humid conditions, quality degrades faster. A practical rule is to buy 4 to 6 weeks of feed at a time unless you have climate controlled storage. Buying in larger quantities to get a price discount only makes sense if the feed quality holds. ### What does a sudden drop in feed intake mean? A sudden drop in feed intake with no change in temperature or water quality is an early warning sign of disease, toxin exposure, or stress. Check dissolved oxygen, ammonia, and nitrite first. Then look for clinical signs of disease such as lethargy, abnormal swimming, or lesions. If you cannot identify the cause within 24 hours, contact a veterinarian. Do not force feed through a suspected disease event. ### How do I account for mortality in the feed budget? Track mortality daily and subtract dead fish from the biomass estimate. If you stocked 10,000 fish and lose 200 in a week, the biomass calculation uses 9,800 fish, not 10,000. Many farmers keep feeding at the original rate out of habit, which means they are feeding dead fish and wasting money. The daily mortality count is a required input to the weekly ration calculation. ### What is the difference between feeding rate and feed conversion ratio? Feeding rate is the percentage of body weight offered as feed each day. It controls how much feed goes into the water. Feed conversion ratio is the amount of feed required to produce one unit of fish gain. It measures efficiency. A farm can have a correct feeding rate and a poor FCR if the feed is wasted or the fish are stressed. Both numbers must be tracked together. ## Related Farming Guides - [Feed Budgeting for Aquaculture: Calculating Costs and Quantities](/knowledge/animal-farming/aquaculture/feed-budgeting-for-aquaculture-calculating-costs-and-quantities) This section will be populated with links to related aquaculture and animal farming guides from this site. Check back for updated content on fish health management, water quality monitoring, pond stocking density, and farm financial planning. ## Related Clinical & Scientific Guides * [Pond Sediment Management and Dredging Options](/knowledge/animal-farming/aquaculture/pond-sediment-management-dredging-options) * [Indoor Aquaculture Facilities: Lighting and Insulation](/knowledge/animal-farming/aquaculture/indoor-aquaculture-facilities-lighting-insulation) * [Greenhouse Aquaculture: Extending Growing Seasons](/knowledge/animal-farming/aquaculture/greenhouse-aquaculture-extending-growing-seasons) ## References - FAO Fisheries and Aquaculture: https://www.fao.org/fishery/en - USDA Aquaculture: https://www.usda.gov/topics/farming/aquaculture - WOAH Aquatic Animal Health Code: https://www.woah.org/en/what-we-do/standards/codes-and-manuals/aquatic-code-online-access/ - FAO Animal Production and Health: https://www.fao.org/animal-production/en/ - WOAH (World Organisation for Animal Health): https://www.woah.org/en/home/ > This article is educational and is not a substitute for veterinary diagnosis, treatment, public-health guidance, or regulatory reporting.