Shrimp Farming: New Way To Diversify Farm Business

Shrimp Farming: New Way To Diversify Farm Business LIVESTOCK Exotic Animals 26-4-43 If you've thought about diversifying your farm operation and you have a farm pond, Bob Boyd has a suggestion that might make you money. Why not try raising fresh water shrimp, also known as prawns. "They're similar to marine shrimp, but larger and have a taste more like lobster than shrimp," says Boyd. "The tails can easily weigh up to 4 oz. each." The Cobden, Illinois, farmer, started growing prawns just a year ago and netted more than $3,000 per acre after his first harvest by selling them live at the farm on harvest day for $8 per lb. "It's a novelty thing right now. People have been interested in buying direct and seeing where they were grown," Boyd says. "They can see you take them out of the pond and pack them in ice, so they know they're fresh." He's also looking at selling them wholesale, servicing local restaurants. And he might launch a hatchery to sell young prawns to others interested in raising them commercially or just for their own use. Prawns won't do well in just any pond. They need clean water that's between 70 and 95 degrees F. Boyd figures that in central Illinois, he has about 100 days from the time his ponds warm to 70 degrees until they cool below that temperature again in the fall. "It takes most of that time to grow them to marketable size," he adds. "Unless you have a way to warm the water, you probably won't be able to grow prawns north of about the center of Illinois." Water can get too warm for them, too. "If the water temperature goes above 95 degrees, they mature, quit growing and your season is over," he says from experience. "I monitor water temperatures and if it gets above 88 degrees, I cool them by draining off about a foot and refilling them with fresh well water that comes out of the ground at about 58 degrees." Prawns are very territorial and once they've claimed an area, they're very aggressive in protecting their turf. They will, in fact, eat their neighbors if they get too close or even if they get hungry. Boyd says you can stock ponds at about 16,000 to 20,000 freshwater shrimp per acre (about 2 square feet each). "We've been working with mesh that we put in the ponds in folds to give us more surface area. We've found this artificial substrate nearly doubles our stocking rates," he says. Boyd initially had feed custom made by a livestock and fish food processor. Now, Purina has introduced a special 36 percent protein prawn feed that combines grain, soybean meal and animal fat. The feed must sink and stay on the bottom where the prawns can get to it. Boyd says there are only four or five prawn hatcheries in the U.S. He buys newly hatched prawns and then grows them in tanks until they're large enough to put into the finishing ponds. "The eggs have to hatch in brackish water. Then the larvae go through 11 molts in their first 25 days of life," he says. Raising prawns is not foolproof. First, ponds for prawn production should be no deeper than 6 ft. You need to monitor the dissolved oxygen level of the water. Overfeeding can lead to excessive growth of algae that can rob oxygen and ruin the pond. "You have to feed carefully, watching to make sure they're cleaning up most of the feed," he says. They're nocturnal, so feeding should be scheduled just before dark. "They'll handle lower dissolved oxygen levels than most fish, but they do need oxygen in the water to survive. Ponds may need some aeration at times to keep oxygen content at the right level. When it's hot, I run my aerators all night, using timers to shut them off during the day," he says. "While you don't need it all the time, if you're not prepared with aeration, you could lose your entire crop in one night. "There are some shrimp diseases but the species I'm growing is resistant to most known diseases," Boyd says. Boyd scheduled a "Shrimp Festival" at the pond on harvest day to market his first crop. His only marketing costs are an ad in the local paper and a sign at the farm. It was so successful he had to turn would-be

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