Evaluation of Formulated Feed for Juvenile Lake Sturgeon Based on Growth Performance and Nutrient Retention

Abstract

This study evaluated the potential of feeding formulated feed to juvenile Lake Sturgeon Acipenser fulvescens and determined the optimal feeding rate of a soft-moist feed on the growth performance and whole-body composition of the fish. Six feeding rates (% body weight [BW]/d) of the soft-moist feed were assigned to each of the 1-week feeding trials: 2%, 4%, 6%, 8%, 10%, and 12% BW/d for trial I; and 0.5%, 2%, 3.5%, 5%, 6.5%, and 8% BW/d for trial II. As reference diets, frozen bloodworms and a dry formulated feed were administered to the fish at feeding rates of 8% and 5% BW/d for trials I and II, respectively. Each treatment was assigned to three tanks, with either 18 fish (trial I; initial BW [mean ± SD] = 3.5 ± 0.05 g) or 15 fish (trial II; initial BW = 7.8 ± 0.1 g) per tank. No mortality was observed during the two trials. Weight gain and feed conversation ratio were significantly better for fish that received the soft-moist feed than for those fed the bloodworms. The dry diet and soft-moist diet resulted in similar growth rates. Growth performance and whole-body lipid and moisture content were significantly influenced by feeding rates in both trials. The tyrosine, isoleucine, lysine, phenylalanine, and valine levels in whole fish were significantly altered by the feeding rates in trial I, whereas only the glycine level was altered in trial II. Optimum feeding rates based on the specific growth rate were estimated to be 7.6% and 6.2% BW /d (or 1.47 and 1.19 MJ·kg BW −1 ·d −1 ) for Lake Sturgeon weighing 3.5 and 7.8 g, respectively. These results indicate that Lake Sturgeon can be given formulated feed after previous acclimation to the formulated feed during the early life stage.

A comparison of one‐slope straight broken‐line, two‐slope straight broken‐line, quadratic broken‐line and quadratic models to estimate an accurate optimum feeding rate for juvenile olive flounder ( Paralichthys olivaceus )

“…Regardless of the fact that water temperature and statistical analysis influence the determination of an optimum feeding rate, the estimated optimum feeding rate generally decreases over increasing body size. Feeding rate studies in other cultured fish species have also been reported (Bu et al, ; Einen, Mørkøre, Rørå, & Thomassen, ; Eroldoğan et al, ; Hatlen, Helland, & Grisdale‐Helland, ; Hung, Conte, & Hallen, ; Lee et al, ; Lee, Zhao, et al, ; Ng, Lu, Hashim, & Ali, ; Storebakken, Hung, Calver, & Plisetskaya, ; Xu et al, ). The increased growth responding to the graded feeding rates tested in both of the current trials is agreeable to the previous findings reported within the same species and in other fish species.…”

“…Although a criticism was raised by Shearer () almost two decades ago for selection of an inappropriate model that results in an erroneous outcome (i.e., selection of a model that does not reflect the feeding rate–response relationship best, resulting in a less accurate estimate), very little attention has still been paid on a question of whether a model chosen by researchers best fits to a given data set. Recently, a very few studies that tested various regression models for the estimation of an OFR reported that the estimates were not identical, indicating that model performance of the tested models was variable (Lee, Haller, Fangue, Fadel, & Hung, ; Lee, Zhao, et al, ). Interestingly, the model, a quadratic broken‐line model, that has been rarely tested by fish nutritionists was turned out to be the best‐fit model among the tested models, including the one‐slope straight broken‐line model, two‐slope straight broken‐line model and quadratic model (Lee et al, ; Lee, Zhao, et al, ).…”

“…Recently, a very few studies that tested various regression models for the estimation of an OFR reported that the estimates were not identical, indicating that model performance of the tested models was variable (Lee, Haller, Fangue, Fadel, & Hung, ; Lee, Zhao, et al, ). Interestingly, the model, a quadratic broken‐line model, that has been rarely tested by fish nutritionists was turned out to be the best‐fit model among the tested models, including the one‐slope straight broken‐line model, two‐slope straight broken‐line model and quadratic model (Lee et al, ; Lee, Zhao, et al, ). On the other hand, this model is well accepted by animal nutritionists when estimating nutrient requirements (e.g., Robbins, Saxton, & Southern, ; Pesti, Vedenov, Cason, & Billard, ).…”

Development of a Growth Model for Lake Sturgeon

“…; Lee et al. ). Natural diets have a high moisture content (up to 90%) and variable caloric levels making calculating feed rates to maximize growth and minimize waste difficult.…”

“…The greatest challenges in Lake Sturgeon culture are the long transition times to adapt to changing diets and the transition from natural food sources to commercially developed feeds. No commercially developed formulated diet exists specifically to optimize growth of Lake Sturgeon, and natural diets have typically produced higher survival rates than formulated feeds (DiLauro et al 1998;Hung and Deng 2002;Bauman et al 2016;Lee et al 2018). Natural diets have a high moisture content (up to 90%) and variable caloric levels making calculating feed rates to maximize growth and minimize waste difficult.…”