Soybean meal is the predominant protein source used in commercial channel catfish feeds because it has the best amino acid profile among all commonly available plant protein feedstuffs. However, soybean meal contain oligosaccharides that are not utilized in fish due to the lack of digestive enzymes and microbial activities in fish guts. These compounds can also interfere with nutrient digestion and promote unhealthy gut microflora.
A study was conducted at Mississippi State to compare a commercially available soybean meal (SBM) to a low oligosaccharide soybean meal (LOSBM) as the main protein sources in channel catfish diets. Four diets were formulated to contain 28 or 32 percent protein with CSBM or LOSBM supplying most of the protein. The experiment involved 20 channel catfish with mean initial weights of 10.0 grams/fish per aquarium; five aquariums per dietary treatment; and the fish were fed to apparent satiation once daily for nine weeks.
Results indicated that regardless of dietary protein levels, the juvenile catfish fed diets containing LOSBM had feed consumption, weight gain and feed conversion similar to those fed diets containing SBM. This experiment supported previous studies that channel catfish utilized SBM well as a protein source and levels of oligosaccharides did not appear to affect the nutrient utilization and growth performance of the channel catfish.