APPARENT DIGESTIBILITY OF NUTRIENTS IN FOUR ANIMAL PROTEIN INGREDIENTS WITH DIFFERENT PROCESSING TECHNOLOGY FOR YELLOW CATFISH (PELTEOBAGRUS FULVIDRACO)

In order to evaluate the digestibility of yellow catfish (Pelteobagrus fulvidraco) to different protein ingredients with different processing, the test diets were consisted of 70% basal diet and 30% test ingredients, including domestic and imported fish meal, chick meal and mealworm meal, and chromium sesquioxide (Cr₂O₃) was used the indicator to determine the apparent digestibility of dry matter, crude protein, crude lipid and amino acids. The yellow catfish with an average body weight of (28.68±0.49) g was randomly divided into 10 groups with 3 replicates per group and 12 fish per replicate. The results using pelleting processed diet showed that the apparent digestibility of dry matter in domestic fish meal was higher than that of the other three ingredients (P<0.05) and the apparent digestibility of protein in mealworm meal was the lowest (P<0.05), and the apparent digestibility of crude lipid in chick meal was significantly higher than domestic and imported fish meal (P<0.05). The results using extrusion processed diet indicated that the apparent digestibility of dry matter in chick meal was significantly lower than that of the other three ingredients (P<0.05), and the apparent digestibility of protein in domestic and imported fish meal was 94%, and the apparent digestibility of crude lipid in chick meal was also significantly lower than that of the other three ingredients (P<0.05). Different processing technology did not impact the apparent digestibility of dry matter using domestic and imported fish meal and mealworm meal in yellow catfish, however, compared to extrusion processing, pelleting processing significantly increased the apparent digestibility of dry matter in chick meal (P<0.05). The apparent digestibility of protein in domestic and imported fish meal and mealworm meal with pelleting processing was lower than extrusion processing (P<0.05), however, chick meal was the opposite. Compared with pelleting processing, the apparent digestibility of crude lipid in imported fish meal was higher with extrusion processing (P<0.05), while for mealworm meal, it was lower with extrusion processing (P<0.05). The apparent digestibility of amino acids is positively correlated with apparent digestibility of crude protein for feed ingredients. In conclusion, different sources and qualities of fish meal lead to different apparent digestibility of nutrients. The domestic and imported fish meal was the best protein source for yellow catfish, and chick meal and mealworm meal were also high-quality protein source for yellow catfish.