SMALL-SCALE TROUT FARMING

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CARE AND FEEDING

The occupants of each pond are fed a 38%protein commercial feed twice a day, if the environmental conditions are right. Should the water become too warm (or the oxygen content drop too low), Rick may feed them only once a day ... or even hold off for a couple of days. He says that feeding has been one of the trickiest aspects of the business to get the hang of, since the correct amount and frequency can be learned only by experience.

The size of the pellets that the trout receive is different for each pond. Because we have only four pools, four feed sizes serve us well, but larger, commercial operations often use a series of six or more. Careful adjustment of the diameter of the rations to the size of the fish causes the finny crop to grow more rapidly, and reduces waste.

We're paying about 22c per pound for the Silver Cup fish feed Rick uses, and we get back about a pound of trout for every two pounds of food. This two-to-one proportion is called the conversion ratio, and any figure lower than 2:1 is considered to be pretty darned good. The best big-time operations approach 1.5:1, and 1.13:1 has been achieved in a laboratory. (Obviously, a 1: 1 ratio would imply complete conversion of food to trout, which is impossible.) Of course, large fish farms (they may have as many as ten acres of ponds) don't feed by hand. Instead, they use automatic feeders that the fish themselves can set off ... allowing the trout to take in as much as they wish.

One of the interesting business aspects of trout farming is that the fish can go with very little food (for up to two weeks at a time) without losing a significant amount of weight. Thus, a grower can afford to wait two weeks for the processor to arrive without having to waste feed on the already market-sized fish. With most other livestock, rations must be maintained usually at no gain in potential income-simply to keep a critter at market weight.

AILMENTS

As is the case with any intensively grown livestock, rainbow trout are susceptible to diseases. So far we've been lucky, but Rick has had to keep a watchful eye out for a couple of problems. One, called "red mouth" because of its major symptom, can bring about losses of more than 30% if unchecked. The illness is usually picked up at the hatchery, so it pays to keep different batches of fingerlings separated in order to prevent healthy fish from contracting the disease. Fortunately, red mouth can be treated by mixing a small dose of Tetramycin in with the feed. (Commercially prepared mixtures with 0.5 to 1.5 pounds of the antibiotic added to each 100 pounds of feed are available, at an additional cost of $1.50 to $2.00 per bag.)

The other common ailment in our area is bacteria gill, which ?again ?is often introduced to farming operations by hatchery stock (it's particularly prevalent in those hatcheries using hard well water). Amazingly enough, the general cure for bacteria gill is to give the fish a salt bath! If the trout are left in a 30% salt solution for about 30 minutes, they'll come out with clean gills. (This may sound like a strange treatment for freshwater fish, but bear in mind that trout are Salmonids, and many of them are anadromous ... that is, they migrate between fresh- and salt water.)

Each day, Rick checks for dead fish and for any that are discolored or have bulging red eyes. With each mortality (they average about one per week, usually from a condition called egg lock), he tries to determine what killed the fish. Should three or more trout die in one week, he'd become concerned and might take a sample to a biologist to determine the cause.

Other daily chores include testing the water for temperature, pH, oxygen content, hardness, and occasionally for dissolved carbon dioxide. Rick uses a Hach Company AL-36B kit to perform these examinations. Observation is also an important part of tending the "flock". Contented fish generally swim in a circle that faces them directly into the flow of water during a portion of their orbit, and if the trout are swimming about erratically, it's a sure sign that they're agitated. Furthermore, about once a month the algae have to be cleaned from the concrete pond walls and bottoms and from the spillways. (So far, at least, the spillways have shown the most accumulation.)

The construction of the four ponds cost just short of $1,700, and we added a shed (for another $400) to house food bags, nets, etc. If the farm can continue to produce 1,600 or more pounds of rainbows per year, the operation should produce an annual cash flow of at least $1,760, and possibly as much as $2,960. Operating expenses at that volume should be around $1,000, so the net profit ought to pay back the construction cost in no more than two and a half years. From then on, a miniature fish farm like ours could be expected to produce a tidy supplementary income ... not to mention a mighty tasty meal from time to time!

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