A new catfish variety bred by ARS scientists—USDA 103—was made available to catfish producers in February 2001. The new, higher performing catfish should have a significant effect on commercial production in the major catfish-producing states—Alabama, Arkansas, Louisiana, and Mississippi. It usually takes catfish 18 to 24 months to grow from birth to market size. This new variety grows 10 to 20 percent faster and is ready for market sooner than other varieties. USDA 103 consumes 10 to 20 percent more feed than other catfish. However, the feed costs only 10 cents per pound and producers can often get 70 to 80 cents per pound for the fish. The new catfish also has different reproductive characteristics. Some USDA 103 catfish can reach sexual maturity at 2 years of age—a year faster than current catfish. They also start producing eggs sooner and produce more of them than some fish now raised commercially. ARS released the new catfish jointly from the Thad Cochran National Warmwater Aquaculture Center with the Mississippi State University Agricultural and Forestry Experiment Station, Mississippi State, MS.

Catfish Genetics Research Unit, Stoneville, MS
William R. Wolters, (662) 686-3596, bwolters@ars.usda.gov
Brian G. Bosworth, (662) 686-3596, bgbosworth@ars.usda.gov

A new vaccine against the most stubborn cases of mastitis—those caused by Staphylococcus aureus bacteria—is showing promise. The vaccine could catch the 50 to 60 percent of staph-caused mastitis cases in the United States that have eluded today's commercial vaccines. An ARS dairy scientist developed the vaccine with the biotechnology company Nabi in Rockville, MD. Large-scale tests to confirm the vaccine's ability to prevent infection have not yet been done. But it is proving effective at curing intractable mastitis cases when combined with antibiotics, according to studies by a Michigan State University veterinary scientist. Antibiotics are often ineffective against staph because the bacteria have become resistant or are holed up in places the drugs can't reach. The new vaccine proved as effective as a herd-specific vaccine developed by the MSU veterinarian, curing 55 to 60 percent of infected cows. And it cleared staph infections in about 10 percent of infected cows in his study, even before antibiotics were administered. ARS is now looking for a agricultural partner to fund further testing and develop a commercial vaccine.

Immunology and Disease Resistance Laboratory, Beltsville, MD
Max J. Paape, (301) 504-8302, mpaape@anri.barc.usda.gov

More than 80,000 DNA gene segments, called expressed sequence tags (ESTs), from cattle and 40,000 from swine have been deciphered by ARS scientists. The program involved producing "libraries" of gene sequences whose expression ultimately results in synthesis of proteins in tissue cells such as muscle, ovary, and hormone-producing glands that affect production traits. The EST sequence information is accessible through databases at the ARS U.S. Meat Animal Research Center (MARC), Clay Center, NB. It also was deposited in the national sequence database at the National Center for Biotechnology Information (NCBI). Researchers worldwide can access the NCBI data for research in medicine and animal science. Researchers at MARC have already been contacted by more than 40 scientists from 9 different countries to make use of the data, with most of the requests coming from biomedical researchers. ARS scientists and genomics companies are also working together under various agreements to develop technologies such as microarrays, also called gene chips, that help identify genes which control traits important to animal health or production efficiency. These studies are expected to one day provide a means to increase production values in livestock herds by increasing the accuracy and speed of selection for specific characteristics. They are also likely to lead to new feed additives or nutritional and management strategies to increase efficiency of production.

Roman L. Hruska U.S. Meat Animal Research Center, Clay Center, NE
Timothy P. Smith, (402) 762-4366, smith@map.marc.usda.gov