As the ethanol industry matures and adopts new technologies, the co-products produced are also changing with their composition adjusted to meet feed industry needs. High protein distillers dried grain with yeast (HP42Y) is a relatively new product which is a variant of distillers dried grains that could be used as an improved protein source in catfish feed formulations. To evaluate the efficacy of HP42Y, a 10-weeks growth trial was conducted on the growth performance of juvenile catfish, Ictalurus punctatus (mean initial weight 1.80 ± 0.05g). In the growth trial, graded levels of HP42Y (0.00, 3.10, 6.20 and 9.30%) were used to replace poultry meal (PM: 6.00, 4.00, 2.00 and 0.00%) and other series of diets were used with HP42Y (5.00, 10.00, 15.00, 20.00, 30.00 and 40.00%) to replace soybean meal (SBM: 51.00, 46.49, 41.90, 37.40, 28.20, 19.20 %). Analysis of Covariance (ANCOVA) revealed a significant interaction between replaced protein (PM and SBM) and the inclusion level of HP42Y on biomass, mean final weight, weight gain, and FCR (P<0.05) of catfish. One-way Analysis of Variance (ANOVA) followed by Tukey multiple comparison test was used to test significant differences between treatment means of the tested variables for each diet type. In PM replacement series, complete replacement of PM resulted in poor performance, indicating a possible nutritional deficiency when the animal protein was removed. As a replacement for soybean meal, increasing levels of HP42Y only resulted in reduced growth of catfish when included in the diet at 30 and 40% respectively. The reduced performance at higher levels may be due to marginal levels of an essential amino acid, e.g. lysine, which warrants further review Results indicate that HP42Y is a good protein source when used at levels less than 30% of the diet.
KEYWORDS: Catfish, growth performance, High protein distillers dried grain, Poultry meal, soyabean meal, alternative protein sources.