NUTRIENT DIGESTIBILITY, DIGESTIVE ENZYME ACTIVITIES AND GROWTH OF KELABAU (Ostechilus melanopleura) FEEDED WITH DIFFERENT CARBOHYDRATE CONTENT

Abstract

This study was conducted to determine the activity of digestive enzymes and the growth of Kelabau (Ostechilus melanopleura) which were fed with different protein content. Four experimental feeds with different protein and C/P content and the same fat content. Feeds A, B, C and D contain protein and C/P levels of 25.14% respectively: 10.64 Kcal, 28.26 %:9.57 Kcal, 31.88%:8.84 Kcal and 34.73%:8.49 Kcal. Kelabau were obtained from the results of cultivation at the Balai Benih Ikan Air Tawar Mandiangin with an initial population weight of an average of 40.91 ± 4.93 g to 45.22±3.07 g with a density of 20 individual reared in a plastic bath measuring 54.3 cm x 38 cm x 31.5 cm and in the volumes 40 litres. Kelabau are given experimental feed 2 times a day on an at satiation basis for 60 days. The activity of digestive enzymes of Kelabau tend increases with an increase in feed protein content up to 31,88% and again decreases to the feed protein content of 34,73%. The highest activity of amylase and protease enzymes was obtained in kelabau consuming C feed (31.88 %) with an average activity of the enzyme amylase and protease respectively 1.55±0.45 IU and 0.038±0.004 IU, while the activity of the enzyme lipase tended to be measured equal to 0.091±0.01 IU. The fish that consuming feed C (31.88 %) showed higher weight growth and specific growth (SGR) compared to other treatments (P<0.05). The highest population weight growth and specific growth rate (SGR) were obtained at treatment C (31.88 %) with an average of 102.53±4.62 g and 2.04±0.11% per days.