Management of Catfish During Troubled Times
We often find ourselves on a treadmill toward higher production levels, higher stocking rates, more aeration, and higher input costs to produce as many pounds of catfish per year as we possibly can. Within the limits of what is biologically possible, given the current state of the art of catfish farming, some might actually be producing 15,000 pounds of catfish per acre per year. However, the inputs for achieving high levels of production can strain our financial resources in times of economic or political uncertainty. In the past, periods of fish meal scarcity have caused catfish feed prices to rise above $400 per ton. Some producers learned lessons then that could apply to the current economic climate in the United States.
What does the future hold?
I think that most of us have to face the reality that fuel and electricity will become more expensive. It is also possible that our feed costs will increase as manufacturers are faced with higher costs. Fish meal and fish oil have increased in price since 2000. A 25% increase in fish meal price is a reflection of the increased demand of fish meal in the aqua and agri industries. Fish oil price has doubled. Some blame the ban on the use of meat-bone meal in the EU as a contributing factor. Therefore, it would be wise to manage your catfish operation to minimize the amount of aeration and if possible to minimize the amount of feed fed. There are several ways to do this that can result in good catfish yield.
Currently, catfish prices are about what they were in 2001. These prices have been blamed on the import of Vietnamese and Chinese catfish, however, the U.S. economy has suffered in general and particularly in some local areas due to layoffs in the textile industry. Now that we are seeing a reduction in business travel and layoffs in the transportation industry, more negative market effect is expected.
Searching for optimum catfish survival?
The number of catfish that survive from the point of stocking to the time they are harvested has had a great effect on the catfish industry. Not only are stocking densities increased to account for the percent of the catfish that do not reach market, but the duration of the growing period has increased to allow larger fish size to replace the catfish that died along the way. In the pond that is never drained, inventory control is difficult. We estimate catfish numbers by their feeding activity, not by actual counts. When fish die, we may only see one in every six or seven that have died. Not only have fish farmers carried catfish longer in order to get the poundage yield up, but processors have marketed the large catfish to allow producers to raise fish that average 3 pounds. As a result of inevitable disease, predation, and incidental mortality, when ponds are drained, survival may average between 60 and 70 percent of the numbers of fingerling catfish that were stocked. It is not unusual for catfish to remain in the grow-out ponds for 18 months or longer. We should be targeting survival of better than 85%. Our catfish should be in ponds for the shortest time possible.
What can we do?
Reducing stocking densities can help if the result is a higher survival rate. Stocking at 5,000 catfish per acre produces the same number of catfish at 85% survival as does stocking at 7,000 catfish per acre and getting 60% survival. Improved survival will occur at the lower stocking density due to reduced stress from crowding. Survival can also be improved by purchasing the largest fingerling you can find, hopefully larger than eight inches in length. You will find that your harvest time will come two to three months earlier by stocking larger catfish. Now that an effective vaccine is available for ESC disease, it would be wise to purchase fingerlings that have been vaccinated. Vaccinated fingerlings used at Tifton add 10 to 15% to catfish survival over an eight month period. Lower stocking densities allow for a better feed conversion efficiency of as much as 20%.
Aeration management will change as stocking densities are reduced. Dissolved oxygen concentration will be higher on the average at lower catfish densities than at higher densities. Eventually, daily feed allocations will equal those when higher densities are stocked, however, feed conversion efficiency will allow more nutrients to be retained in the catfish body rather than wasted into the pond environment. Pond water quality will still need to be carefully monitored. Aeration should be applied at the appropriate times, usually when dissolved oxygen is predicted to fall below 3 ppm.
Stock threadfin shad or develop an algicide treatment program in order to reduce algal population density. You should manage for off-flavor with both biological and chemical controls. Stock fathead minnows in order to provide control of the proliferative gill disease. The use of fish as biological controls will improve catfish survival as well as provide a food supplement.
Use care in your feed purchases. Plan ahead so that you can book feed at the lowest prices. Consider using feed that has little or no fish meal. Meat-bone meal and blood meal can be efficiently utilized in catfish diets as a replacement for fish meal. Request a discussion of feed composition with your feed manufacturer. Some byproducts of the ethanol industry may be good substitutes in catfish feed, like distillers grains or corn gluten feed. Offer feed to your fish when water quality parameters are good, usually after mid-morning to obtain better feed conversion efficiency.
How long will it last?
Before the terrorist attack, some economic downturn had already affected the catfish industry. Then high energy costs hit the world economy. Feed costs were predicted to rise. We do not know the long term effects of our energy policies, however, we expect the economy to recover over a period of years. It will take time to change our catfish management philosophy after a period of careful evaluation for our individual circumstances. Some may want to change fish species, lower stocking densities, or idle ponds. Plan now and act on your plan, soon.