Optimum Dietary Protein to Energy Ratio for Channel Catfish Fingerlings, Ictalurus punctatus

Abstract

Twenty-one semipurified diets were formulated to determine the optimum protein:energy ratio (P/E) for channel catfish fingerlings. Seven crude protein levels and three energy levels at each protein level were utilized. The protein, lipid, and digestible carbohydrate sources were hexane-extracted whole egg powder, salmon-corn oil mixture, and white dextrin, respectively. After an initial 2 week conditioning period, the experimental diets were fed in triplicate to groups of 30 +/- 3 channel catfish fingerlings weighing 205 +/- 10 g and kept in 110 liter flow-through aquaria at 26.7 +/- 1.1 degrees. The diets were fed at a rate equalling 3% of the total wet body weight/day divided into three equal feedings and adjusted weekly for 9 weeks. An approximate fivefold increase in body weight was observed. These data indicate that the concept of P/E ratios must be restricted to diets containing adequate levels of protein and total energy. Based on average daily gain, diets containing energy levels between 275 and 341 kcal/100 g had an optimum P/E ratio of approximately 88 (24-36% crude protein). Diets containing 24% crude protein and 275 kcal/100 g diet appeared to be utilized more efficiently in terms of percent protein deposited than diets containing higher crude protein levels.

Optimal dietary protein level improved growth, disease resistance, intestinal immune and physical barrier function of young grass carp (Ctenopharyngodon idella)

“…Six experimental diets with different protein levels (170.0, 210.0, 250.0, 290.0, 330.0 and 370.0 g kg À1 diet) were used. The diets were formulated to be iso-energetic according to the method of Garling et al [31]. According to Kjeldahl method, protein contents in the experimental diets were measured to be 169.2, 204.7, 244.3, 283.2, 323.3 and 366.3 g kg À1 diet.…”

Effects of dietary protein levels on the disease resistance, immune function and physical barrier function in the gill of grass carp ( Ctenopharyngodon idella ) after challenged with Flavobacterium columnare

“…Six experimental diets with different protein levels (170.0, 210.0, 250.0, 290.0, 330.0 and 370.0 g kg À1 diet) were used. The diets were formulated to be iso-energetic according to the method of Garling et al [36]. According to Kjeldahl method, protein contents in the experimental diets were measured to be 169.…”

Growth and feed utilization by F4human growth hormone transgenic carp fed diets with different protein levels

“…In the present study, isoenergetic diets with protein levels ranging between 20 and 40% did not produce differences in the growth rates of both the transgenic and non-transgenic common carp. In most studies on the effect of dietary protein : energy ratio on fish, a fixed feeding rate was used (Garling & Wilson, 1976;Henken et al, 1986;Das et al, 1991). In the present study, fish were fed to satiation twice a day.…”