Effect of Feather Peptide Meal on Growth, Body Composition, and Digestive Enzymes of Darkbarbel Catfish (Pelteobagrus vachelli)

Effects of peptide meal made from feathers in the feed on the growth, body composition, and digestive enzymes of the darkbarbel catfish, Pelteobagrus vachelli, were studied. Triplicate groups of 30 fish with an averaging weight of 25(2 gin each group were randomly selected to be fed ondiets formulated with the addition of 0, 5, 10, 15, or 20% of the peptide meal for 60 days. The results showed that(1) the peptide meal significantly affected the weight gain rate(WGR), specific growth rate(SGR), and total feed intake(TFI) on the fish (P0.05); (2) a 10% addition of the meal in the feed was determined to be appropriatefora diet that produced a WGR of 117.48% on the fish; (3) the WGR and SGR of the fish decreased significantly when the meal addition increased to 15% or 20%; (4) with increasing amount of the peptide meal, the feed conversation ratio increased gradually; (5)no significant differences were found among all groups on the muscle moisture, lipid, protein,or ash content on the fish fed on diet with 20% peptide meal addition (P0.05); (6)the trypsinactivity in thehepatopancreas of the fishsignificantly increased with increasing meal addition (P0.05), but no significant differences were found between 5% meal addition and control; (7) the trypsin activities in the intestine and hepatopancreas showed a similar trend, however, the ratio of intestinal trypsin/hepatopancreatic trypsinsignificantly decreased at 15% meal addition; (8) no significant differences was observedon the amylase activities among all groups (P0.05); (9) at 5% meal addition, the lipase activity in the intestine or hepatopancreas of the fish was lowest among all groups (P0.05); (10)with a 10% meal addition, there was no significant differenceobserved in the intestinal lipase activity, and the hepatopancreatic lipase activityremain same as control up to 15% of the meal addition; (11)the pepsin activities in the stomach of the fishfed with different diets were significant higher than control, and the 15% and 20% meal addition were higher than 5%, while 10% addition was higher than control (P0.05); (12)no significant differences were evidenton the stomach pepsin activities in the hepatopancreas of the fish from all groups. It appeared that a 10% addition of the feather peptide meal to the basal diet could be satisfactorily applied for feeding juvenile darkbarbel catfish.