Abstract
In this study, three growth trials were conducted to check the efficacy of poultry corn by-product meal, which was a combination of wet poultry processing waste and corn that was co-dried. It was relatively a new product, and its first growth trial was conducted in a laboratory (aquarium study) to evaluate the substitution of whole corn meal with poultry plus corn by-product meal (PCBM) in practical diets for channel catfish. In this trial (84 days culture period), 7 levels of PCBM (0, 5, 10, 15, 20, 25 and 30%) were evaluated in a practical diet containing 32% protein and 6% lipid. The results indicated that fish fed PCBM20 had the highest FW, WG and WG% among all the treatments, and these values were significantly higher (p < 0.05) than at baseline or with PCBM5 treatment. The second trial (fingerlings to sub-market) was conducted in 12 raceways with 4 levels of PCBM (0, 10, 20 and 30%) and 600 fish (mean initial weight 42.3 ± 5.06 g) in each raceway. After 143 days of culture, the results demonstrated that there were no significant differences (p > 0.05) between the FW, WG and WG% and the survival of the fish. To validate our results again, the third trial (sub-market to market) was conducted in 6 raceways with 2 levels of PCBM (0 and 30%). A total of 600 fish (mean initial weight 136.8 ± 6.3 g) were stocked in each raceway. The results revealed that there were no significant differences (p > 0.05) between the FW, WG and WG% and fish survival after the culture period of 133 days. In all three trials, upon termination, the hepatosomatic index (HIS), the intraperitoneal fat (IPF), and the dress-out (headed and gutted) percentages were measured for trials 2 and 3. The results showed that there were no significant differences (p > 0.05) between all these parameters except for HIS in trial 1 and IPF in trial 2 (p < 0.05). In conclusion, PCBM can be used up to 30% in the diets of channel catfish.