When to feed your fish. Under normal rearing conditions, it is best to feed your fish at least once a day, usually for six days a week. Feed more often if possible, particularly for juvenile fish (see Section 10.3, paragraphs 13 and 14). In some conditions, such as limiting low temperatures, feed.
By Jeffrey M. Hinshaw, North Carolina State University and published by the Southern Regional Agricultural Center and the Texas Aquaculture Extension Service.
Trout Production: Feeds and Feeding Methods - By Jeffrey M. Hinshaw, North Carolina State University and published by the Southern Regional Agricultural Center and the Texas Aquaculture Extension Service.In trout farming, the amount and suitability of feed used determines the profitability of production. Trout and other salmonids can efficiently digest foods that contain primarily protein (mostly from fish), and can obtain some of their energy from fats and, to a lesser extent, from carbohydrates.
Fry and fingerling trout require a higher protein and energy content in their diets than larger fish. Fry and fingerling feed should containapproximately 50 percent protein and 15 to 20 percent fat. Feeds for larger fish typically contain 38 to 45 percent protein and 10 to 18 percent fat. The switch to lower protein formulations usually occurs at the transition from a crumble feed to a pelleted ration, called a growout or production diet. High energy diets may contain 45 to 50 percent protein and 18 to 24 percent fat.
Several brands of high quality commercial trout diets are available, and although a farm could produce its own fish food, it is not usually economical to do so.
Feed quality
Trout feeds have been greatly improved in the past decade. Fish meal is still the primary source of protein, but protein digestibility has been improved and ash content has been reduced by using fish meal processed at lower temperatures (low-temp fish meal). Also, diets now have higher energy levels that help fish use protein more efficiently.
Increasing the energy level in the diet limits the fishs use of protein as an energy source. Trout are being grown efficiently with dietary fat levels (mostly from fish oils) as high as 18 to 28 percent, provided the ratio of digestible protein to energy remains in the correct range. This ratio is expressed as grams digestible protein per megajoule of digestible energy.
Ask your feed manufacturer to tell you the ratio of protein to energy in your fish feed, especially if you plan to use high energy diets. For typical high energy diets the ratio should be about 20:1. Feeds with ratios significantly higher than 20 may contain excess protein or large amounts of protein that trout can not digest easily. Feeds with lower ratios may contain excess fat, and could affect flesh quality and dress-out percentages. However, specific diet formulations may vary considerably from this ratio and still be highly efficient if properly formulated.
Feeding practices
Trout producers usually try to grow the fish as quickly and efficiently as possible while maintaining uniformity of growth and degrading water quality as little as possible. To accomplish these goals it is important to feed the correct amount. The amount of feed trout require depends on water temperature and fish size. Smaller fish have faster metabolic rates and need more feed relative to their body weight than do largerfish. Because fish are poikilothermic (cold-blooded), their body temperatures and metabolic rates vary with water temperature. Fish in warmer water need more feed than fish in cooler water.
The minimum temperature for growth in trout is about 38°F. At this temperature and below, appetites are suppressed, digestive systems operate very slowly, and trout require only a maintenance diet (0.5 to 1.8 percent of body weight per day, depending upon fish size). Feeding more than this wastes feed. In warm water (above 68°F), a trouts digestive system does not use nutrients well and more of the consumed feed is only partially digested before being eliminated.
This nutrient loading of the water, coupled with the generally lower oxygen levels in warm water, can easily lead to respiratory distress. Inwarm water, feeding rates should be reduced enough to maintain good water quality and avoid wasting feed. The optimum temperatures for growing trout are 55 F to 65o F. At this temperature range feeding rates should be at maximum levels (1.5 to 6.0+ percent of body weight per day).
The best way to determine the correct amount and size of feed for trout production is to use a published feeding chart, usually provided by the feed manufacturer. These charts are useful guides, but you may need to make adjustments to fit specific conditions on your farm. Under most circumstances, fish need to be fed less than they will eat. Overfeeding will cause the fish to use the feed less efficiently and will notincrease growth rates significantly.
To determine the appropriate amount of feed, know the number and size of the fish on your farm. At water temperatures above 55o F, make a sample count of the fish at least monthly and adjust feeding percentages accordingly. In cooler waters, a sample count every 1 to 2 months usually is adequate. Good growth records for trout on your farm will help you predict seasonal growth rates. Do not overfeed. Once feed settlesto the bottom of the tank, small trout will ignore it. Excess feed reduces water quality and promotes disease. Remove any excess feed promptly.
How to feed trout
Once a high quality feed has been selected and the correct amount of feed determined, the next consideration is how to feed the fish. The best method depends on the size of the fish. Trout will begin to consume prepared diets within 7 to 10 days after hatching. At first, fry should be fed a small amount by hand eight to ten times per day until all the fish are actively feeding.
A large kitchen strainer makes an excellent tool for distributing the finely ground starter feeds used for trout. After the initial feed training, an automatic feeder is most practical, with two or three hand feedings daily so that you can observe the fish. As the fry grow, the frequency of feeding can be gradually decreased to about five times per day. When fed nearly to satiation, trout will consume roughly 1 to 2percent of their body weight in dry feed at each feeding. The feeding frequency should be adjusted to obtain the desired feeding percentage. Fry gain weight rapidly and should be sample counted weekly for the first 4 to 6 weeks. The daily feed ration should be adjusted accordingto their weight. Feed should be distributed over at least twothirds of the water surface when fry are less than 2 inches long.
This gives them easy access to the feed and helps to keep a uniform size within the population. After fingerlings are moved out to tanks or earthen ponds, there are several feeding alternatives. Hand feeding each day until the fishes appetites are suppressed usually produces the best combination of feed conversion efficiency and growth rate. However, hand feeding is labor intensive and may not be practical on a large commercial farm. Hand feeding is the best way to train fish to use demand feeders or to administer medicated feed to sick fish.
Figure 1: Demand feeder used introut production. |
With careful adjustment of demand feeders, rapid weight gain and efficient feed utilization can be attained. The use of demand feeders can eliminate the sharp oxygen decline that occurs when fish are fed by hand or machine a few times each day. Demand feeders also reduce thelabor cost associated with daily hand feeding. Disadvantages include the tendency to overfeed because of improper feeder adjustment, and food release only in a small section of the pond or tank. Overfeeding with demand feeders can be a problem with larger trout.
Demand feeders should be located at intervals of about 25 to 30 feet along the tank walls. Several days feed can be loaded, but for best feeding efficiency it should not be replaced until the feeding period has passed. Adjust the feeder so that the feed is removed over the entire time for which the feeder is loaded. Even if demand feeders are used, feeding according to a feed chart is recommended for best performance.Whether feeding by hand or with a mechanical distribution system, feed should be distributed throughout the pond and should not accumulate on the bottom. In concrete tanks, trout will feed on some pellets that fall to the bottom, but trout will rarely pick up pellets from the bottom of earthen ponds.A good way to ensure that all the trout in a tank have access to the feed when hand feeding or using automatic feeders is to distribute twice as many feed pellets as fish throughout the tank in a 5- to 10- minute period. Repeat this process at 10-minute intervals until all the ration for that feeding has been distributed or until the feeding activity declines.
Feeding should be restricted when water temperatures drops below 40o F or rises above 68°F. Feeding rates also should be reduced orfeed withheld entirely when fish are sick. Fish should always be kept off feed for a while before handling or transporting. For routine handling, such as grading or vaccinating, 24 hours without food is sufficient. If fish are to be transported off the farm or are to be processed, they should be kept off feed for at least 3 to 4 days, or longer if the water temperature is low. Trout producers do not usually use finishing diets before processing, but feed may be withheld for several weeks if the fat content of fillets needs to be reduced.
Special purpose feeding
There are specialty trout feeds for specific production goals. Phosphorus levels in some feeds have been reduced to 0.7 to 0.9 percent by weight in order to reduce the amount of phosphorus released to the environment from trout culture. Highly digestible or nutrient-dense diets are available for use where reducing solid waste is a concern. Nutrient-dense diets are typically high in fish meal protein and lipids and lowin carbohydrates, especially uncooked starches and fibrous materials.
There are also specialty feeds containing antibiotics (tetracycline hydrochloride or potentiated sufadimethoxine), immune stimulants (beta-glucans and other yeast derivatives or other compounds), or carotenoid pigments (canthaxanthin or astaxanthin).
They are more expensive than regular diets and should be used only when appropriate. Feeds containing antibiotics should be used only after the diagnosis of a bacterial condition susceptible to treatment. Immune stimulants have only recently become available and are not yet in widespread use. Feeds with carotenoid pigments impart a pink or red color to the flesh and do not affect fish health or growth rate. Pigmentation can be achieved in about 3 months when fish are actively growing, and in about 6 months in cold water. Other specialty diets include an enriched diet for broodfish and a high-fat diet (16 to 24 percent fat) for producing an oilier fish used for smoking or for specialty markets.
Feed And Grow Fish Map Drawn Across
Further Information
For more information on Trout Production, see the links below:
Source: Southern Regional Agricultural Center and the Texas Aquaculture Extension Service - May 1999Welcome to AzzaMods.com
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Hi guys! It's been a while.
We wanted to give you guys a progress update to let you know what we've been working on over the past few months.
Preface:
This update is still a work in progress, and we will release more information when it's available to use, or as we polish off the features, depending on how long it takes.
Why so quiet?
This project is a software development project, and we can work on the underlying code base for weeks without anything that is visible to you.
We also need to do a significant amount of 'Research and Development' to figure out how to create the best possible product for you guys to enjoy -- We're going to talk about some of the R&D we've done below, to give you a taste of where our time and effort has gone.
We've had to study and learn a significant amount of new technologies and have invested thousands of hours of our time to get to this stage.
Alpha Release
We plan to release an alpha build in the future for our new launcher (and website) -- Details to follow, however, the old mod launcher will remain active / usable until our alpha is stable enough for everyone to make a transition over.
New Launcher
This launcher still needs a few more runs through to polish up and ultimately make it a lot nicer, but we wanted to at least show you the current version, do expect it to improve the next time you see it:
We've rebuilt the launcher from the ground up in a brand new framework (Electron), focusing on making the experience reliable, user friendly and allowing for much more customisation of games.
Universal Unity Games Support
A large focus for this release is supporting a much larger library of Unity based games -- Our new modding method no longer requires patching of files, and will work even AFTER the game has been launched.
We have tested this across a library of more than 15 games and the launcher has worked for all Unity based games we've tried it with -- previously we needed to manually add support on a game by game basis which could take weeks just for a single game -- this is a huge time save now that games 'just work'.
Streamlined Mod Development Process
Our new launcher makes it a lot easier to create new mods, meaning we will have the ability to release mods on a more frequent basis -- our hope is to eventually allow any of you to create mods, with the support of a tutorial series we aim to produce.
Universal Mods
We now have the ability to create what we call a 'universal mod' -- A mod that works across more than one game. Our first proof of concept universal mod allows you to change the gravity and game speed (timeScale) of any Unity game in real time. We're exploring other possibilities for mods that will make sense to work across multiple games.
Key Binds
This is a feature we already released in our existing mod launcher, however, it's been polished and improved since the last release -- This essentially allows you to bind mod options to keys, for example, you could create a key bind to spawn fish when pressed, or interact with any of the options within the launcher.
Content Creation & Exploration Tools
We have spent a lot of time building some awesome new tools which work universally across all Unity based games (that we've tested). These include:
Inspector - View all of the Game Objects that are in the level (scene), allows you to change values in real time, explore the underlying game functionality, and essentially create (non-persistent) mods in game in real time :) This is super fun to play with FYI :) Prefab Editor - Ever want to customise the stats, textures, or really any of the values in the game? This tool lets you explore all of the prefabs, and PERSISTENTLY edit any of the properties and underlying textures of the prefab. Level Browser - Ever wonder if there's hidden maps in a game? Ever get stuck on a level? We've created a tool that lets you easily move between any level (scene) in Unity based games. We're currently undergoing R&D for allowing custom maps, however, custom maps are still in a very early phase of R&D. SDK - This is likely something that won't ship with the Alpha release, however our SDK (Software Development Kit) allows anyone to easily create a mod that integrates directly with the mod launcher itself -- Our vision is to polish the SDK, create a modding tutorial series, and teach you guys how to make mods using our launcher.We'll do some updates in the future to show you these tools working, and again, once they are all polished to a state that's user friendly, expect to see most of them in the Alpha :)
Thanks for the support!
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