May 6th, 2002

Trout Spawning, Hatchery Style

Sacfry

By Steven H. McGarthwaite


On the return trip from the 2002 Texas Fish-In, my wife and I stopped to stay a few days at Branson, Missouri. This was the portion of the trip that I promised my wife would be her vacation. While in Branson, I visited a fly-fishing store in the downtown area. There I learned of the Shepard of the Hills Trout Hatchery in Branson. Getting down on my knees, I pleaded with my wife to let me do this story for FAOL. She relented and allowed me to do more of my fly angling work. She even went with me to the hatchery, just to make sure I didn't return to the fly fishing store to buy that old South Bend cane fly rod that was priced at $450. ~ SHM


Shepard of the Hills Hatchery
Shepard of the Hills trout hatchery was opened in 1959, and has raised trout ever since then, except between 1976 to 1980 when it was being renovated. It is the newest hatchery in the Missouri Department of Conservation. There are 5 hatcheries run by the Missouri Department of Conservation, but only Shepard of the Hills and one other hatchery have brood stock. Shepard of the Hills hatches German Brown Trout, and two types of Rainbow Trout. The German Brown Trout spawn in the autumn, and the Rainbows are divided into two groups, one spawns in the spring and the other in the autumn.

Rainbow Broodstock

The brood stock (only Rainbows) are kept up to 6 years, and these are released when the fish is past its prime for breeding purpose. Most of the brood stock at Shepard of the Hills is fall spawning Rainbows. The average size of a release brood trout is 8 pounds or larger. Shepard of the Hill's releases 25% of the brood stock every year. The brood stock population varies between 6,000 and 8,000 trout.

From Top of the Dam The water for the hatchery is supplied from the Table Rock Dam. Shepard of the Hill Hatchery is located at the dam's base. The water is drawn from 350 feet down (approximately 50 meters). Temperatures vary from the lake between 40 to 52 degrees F (4.4 to 11.1 degrees C). They also use well water, which averages 58 degrees F (14.4 degrees C), with these two sources they can control the temperature of the water in the hatchery. The hatchery uses 17,500,000 gallons (70,000,000 liters) of water daily. The water travels thru gas diffusion towers that allow the water to move over several aluminum screens, breaking up the water, adding oxygen and removing nitrogen. Water temperature at the hatchery is on average 55 degrees F (12.8 degrees C).

Shepard of the Hills TROUT CHOW
Crude Protein...not less than 45%
Crude Fat...not less than 18%
Crude Fiber...not more than 3%
Ash...not more than 12%
Sodium...not more than 2%
Vitamin A...not less than 10,000 IU/KG
Vitamin D...not less than 500 IU/KG
Vitamin E...not less than 250 IU/KG

Feeding Time
The food used is a commercial prepared mixture, which is sized at the hatchery for the different stages at the fish growth. The Shepard of the Hills hatchery can store 26 tons of trout food, and uses 1,600 pounds daily. The cost for food to raise one trout to release size (10 to 12 inches) is 60 cents.

During the spawn, the brood stock is separated by sex, and the females are checked for their state of readiness to spawn. They are dipped from the run, and place in a large tub of spring water to relax. When they are relaxed they are picked up by hand and light pressure is exerted on their belly. If the female is ready to spawn the eggs are easily released. This release is from 40 to 150 eggs, the eggs are checked for quality, if over-ripe eggs are detected, the female is stripped of the eggs, and the eggs are discarded. This helps the female from having to re-absorb the eggs. Females that are ready to spawn are then placed in a holding tank that has a mild anesthetic to help them relax. The other females that are not ready are returned to the run, and checked in another 5 days.

Brood Stock Runs

The anesthetized males are stripped of their milt, and the milt can be stored in plastic bags that are inflated with oxygen and stored on their sides in a refrigerator, so the milt is kept thin. Milt can last for many days when refrigerated and properly stored. Afterwards the males are returned to the run.

The females that are ready to spawn have the eggs removed by an air-spawning method using a needle and oxygen is injected at 2 to 3 pound pressure. This method is less stressful on the female, and the eggs are cleaner and are less damaged. Depending on size, each female can supply 3,000 to 5,000 eggs. The eggs are collected in a collecting pan and when the pan is filled the milt is added. The mixture is stirred using a finger, although the old-timers use to insist on mixing with a turkey feather.

Eye up Stage After the mixing is done, the eggs are then transferred to a bucket of water to harden. This water hardening takes about 45 minutes, and allows the eggs to absorb water and become round and firm. When that step is done, the eggs are sampled and weighted to determine how many eggs there are per ounce. The eggs are transferred to an Upwelling (Incubator) Jar. There the eggs remain for the 28 days it takes for them to hatch, depending on the water temperature. Two days before the eggs hatch (Eye Up), they are transferred to a Sac Fry Tray.

Sac Fry

In the sac fry tray, there is metal mesh to hold the eggs in flowing water, this helps the hatched sac fry to break from the eggs, and swim to the bottom of the tray. The water flows over the mesh; helping get rid of the dead eggs. Shepard of the Hills has a 90% success rate on hatched sac fry from eye up. The sac fry remain in the sac fry tray for about two weeks, until they have completely absorbed the entire sac. At which time they become Swim Ups, and are transferred to the Swim Up tray.

Fingerling

In the Swim Up tray, the swim up's are at the beginning fed 12 times daily with the commercial food, ground to talcum powder size. Later the feedings are reduced, and the amount of food increased. Even with daily cleaning of the trays, and medication where needed, 2% to 5% of the swim ups die from various reasons. At three inches they are moved outside.

Carrying Capacity
Up Well Jars hold 150,000 trout eggs
Sac Fry Trays hold 75,000 trout
Swim Up Trays hold 10,000 to 25,000 trout
4 to 5 inch pool holds 80,000 trout
7 to 8 inch pool holds 45,000 trout
10 inch pool holds 30,000 trout

Fingerling Tanks
Shepard of the Hills raises 800,000 trout for Taneycomo Lake annually. (Taneycomo stands for TANEY County Missouri). Shepard of the Hill also supplies 400,000 eggs and fingerlings to other hatcheries for stocking in their areas.

Brown Trout spawn in the fall. Because Shepard of the Hills does not carry Brown Trout brood stock, they must catch the Browns as they do their spawning run, and raise them in 4 dirt runs, and a dirt pond. (German Browns do not fare well in concrete runs or pools.) They raise the German browns for prize trout releases.

Rainbows raised by the Missouri Department of Conservation came from the McCloud River Station in California, and the Donaldson Rainbows came from the Flaming Gorge, Utah. Breeding Donaldson females with McCloud males created the Arlee strain that spawns in the spring. The German Brown trout are also from the Flaming Gorge, Utah.

Leah Eden

I was surprised at the amount of work and time that is required to raise trout. The total hatchery layout is quite extensive. The sad point is the news of 80% of newly release 10-12 inch trout are caught and kept, within two weeks of release into the water. But the 20% that survive past the two weeks are still a higher success ratio, compared to natural spawn success rate.

I wish to say thank you to the staff at the Shepard of the Hills Trout Hatchery, for their help and cooperation. Special thank you to Stephanie Goodwin who compiled an information packet for my use in this article (greatly appreciated, and very needed). Special thank you to Leah Eden, who gave me a personal tour of the Hatchery facilities, her knowledge of the process and answering tons of questions were of great help to me in understanding the total picture on just how trout are raised.


A special thank you to my wife Kathy for helping me to do this story. She had to drive across the top of Table Rock Dam 6 times for me to get an Arial picture of the trout hatchery below the dam. ~ Steven H. McGarthwaite

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