Different Dietary Levels of Protein to Lipid Ratio Affected Digestive Efficiency, Skeletal Growth, and Muscle Protein in Rainbow Trout Families

Abstract

Normal Protein (NP) and High Protein (HP) diets were provided to rainbow trout families from juvenile to maturity. Muscle protein concentration increased during growth and the protein to lipid (P/L) ratio was doubled at late stage with respect to the dietary P/L ratio. The HP-diet fish showed higher protein deposition in body and white muscle, and had lower condition factor due to protein deposition associated more with body length than body weight. Fish growth rates were decreased at maturation, and the HP-diet fish showed lower growth rate including the activity ratio of trypsin to chymotrypsin (T/C ratio) and feed efficiency. Trypsin and chymotrypsin specific activities were related to dietary protein levels, and the T/C ratio was related to intestinal weight and growth rate independent of the enzymes specific activity levels. The families with high growth capacity could double increase white muscle P/L ratio levels, compared to low and medium growth families, if they were fed on HP-diet. The digestive enzyme extracts from high growth families resulted in higher in vitro protein digestibility for all diets. The effect of dietary P/L ratio on digestion, skeletal growth (length) and the white muscle P/L ratio in fish with different growth capacities is illustrated.

Development of Enzymes andIn VitroDigestibility during Metamorphosis and Molting of Blue Swimming Crab (Portunus pelagicus)

“…This is partly concurred with the indications that amylase and protease activities were modulated by the composition of the diet [10] and increased with respective increases in dietary glucides and proteins [11]. Moreover, the levels of trypsin specific activity have been found to relate to diet consumption [12] or protein consumption [13]. The different responses in the enzyme activity levels could be due to variations in the levels of food supply of whether it was under food-saturating condition or not and also due to differences in digestibility quality of the diets as well as the animal growth stages where the levels of enzyme development varied.…”

“…The conditions for the analyses of the enzyme activities are based on the preliminary study on characteristics of the digestive enzymes in P. pelagicus [23]. The activity ratio of trypsin to chymotrypsin (T/C ratio) is also studied, as it has been shown to associate with feed efficiency [24][25][26][27][28] and fish growth rate [13,24,[27][28][29][30][31][32][33]. Moreover, the in vitro digestibility of protein in different feed raw materials for future feed formulation is also studied using crude enzyme extracts from different growth stages of P. pelagicus.…”

The Age Dependent Activities of Digestive Enzymes in Rasbora, Rasbora lateristriata Blkr., (Pisces: Cyprinidae)

“…Trypsin activity is higher than chymotrypsin, reflecting the absence of growth inhibition in the fish, and the high activity of trypsin can be an indicator of increased growth and efficiency of feed on fish ( Chan et al, 2008;Rungruangsak-Torrissen et al, 2009).…”

Effects of different modified diets on growth, digestive enzyme activities and muscle compositions in juvenile Siamese fighting fish (Betta splendens Regan, 1910)

“…The extinction coefficient for RNA is E 260 = 40 µg RNA ml -1 , and for protein is E 280 = 2.1 mg protein ml -1 . Lipids were extracted using ethyl acetate as described by Supannapong et al (2008) and Rungruangsak-Torrissen et al (2009). All values were expressed on wet weight basis.…”

“…These parameters were higher in higher growth group (microwave-irradiated dietary group), although some parameters may not show statistically different (Tables 3 and 4). The specific activities of the alkaline proteases trypsin and chymotrypsin, including T/C ratio, are important for understanding growth performance quality and feed utilization efficiency in different fish species (Sunde et al, 2001(Sunde et al, , 2004Rungruangsak-Torrissen, 2007;Rungruangsak-Torrissen and Fosseidengen, 2007;Rungruangsak-Torrissen et al, 2009 including Siamese fighting fish, however, the A/T ratio was not found to associate with fish growth (Thongprajukaew, 2011). The significantly higher growth performance and A/T ratio, but not T/C ratio, in microwave-irradiated dietary group may indicate higher energy requirement for protein utilization and growth in this group than the other groups.…”