Effect of Dietary Carbohydrate‐to‐lipid Ratios on Growth Performance, Body Composition, Hepatic Enzyme Activities, and Digestive Enzyme Activities of Juvenile Australian Redclaw Crayfish, Cherax quadricarinatus (von Martens)

Abstract

A growth experiment was conducted to determine the optimal dietary carbohydrate-to-lipid (CHO : L) ratio for the Australian redclaw crayfish, Cherax quadricarinatus (von Martens). Specimens were divided into five treatment groups and fed twice a day to apparent satiation with isonitrogenous and isoenergetic diets with dietary CHO : L ratios of 10.75:1, 5.99:1, 3.60:1, 2.18:1, or 1.33:1. Over the 8-wk growth trial, redclaw crayfish fed the 2.81:1 and 3.60:1 diets exhibited better weight gain (WG), specific growth rate (SGR), and feed conversion ratio (FCR) than specimens fed the other diets (P < 0.05). Activities of hexokinase and pyruvate kinase were stimulated by elevated levels of dietary carbohydrate, whereas activities of lipase and alkaline phosphatase were stimulated by elevated levels of dietary lipid. Dietary CHO : L ratios significantly affected digestive enzyme activities (P < 0.05), except for trypsin (P > 0.05). On the basis of the analysis of growth, FCR, and costs of culturing redclaw crayfish, the optimal growth and costs occurred when the dietary carbohydrate and lipid levels were 290.10 g/kg and 80.70 g/kg, respectively, corresponding to a CHO : L ratio of 3.60:1. These results indicate that a CHO : L ratio of 3.60:1 is optimal for rearing redclaw crayfish and that this species uses carbohydrate more efficiently than lipid.

Growth and metabolic responses of juvenileMacrobrachium nipponenseto different dietary carbohydrate levels

“…In this study, hepatopancreatic HK activity and mRNA expression increased significantly as the dietary carbohydrate level was increased. As reported for M. nipponense , redclaw crayfish fed a high‐carbohydrate diet show increased HK activity (Zhu et al., ). In contrast, HK activity is low in L. vannamei and not affected by the dietary carbohydrate level (Rosas et al., ).…”

“…However, Shiau and Peng () reported that starch can replace some dietary protein in the P. monodon diet. A study on juvenile Cherax quadricarinatus showed that maximum weight gain and the best feed conversion rate were obtained when the crayfish were fed the optimal dietary carbohydrate‐to‐lipid ratio (Zhu et al., ). A dietary cornstarch level of 203 g kg –1 was appropriate for juvenile Procambarus clarkii fed several isonitrogenous practical diets (Xiao et al., ), and 100–200 g kg –1 was the optimal cornstarch level for Litopenaeus vannamei fed diets containing different levels of corn starch balanced with cellulose (Guo, Liu, Tian, & Huang, ).…”

Effect of different sources and forms of dietary carbohydrates on growth performance, body indices and lipogenesis activity of striped catfish Pangasianodon hypophthalmus fingerlings

“…In 2016, this country accounted for 1.19 million tonnes of the total global production amounting to 2.6 million tonnes (Food & Agriculture Organisation; FAO, ). High levels of worldwide production of P. hypophthalmus have increased the demand for appropriate and cost‐effective feeding and reinforced the importance of carbohydrates (CHO) as the most inexpensive energy sources in the fish diet (Tran‐Duy, Smit, Van Dam, & Schrama, ; Zhu et al, ). Carbohydrates serve as an important source of energy in most mammals, but their function is limited in fish, particularly in carnivorous species (Stone, ; Wilson, ).…”

Growth, body composition and digestive enzyme responses of Caspian Kutum,Rutilus frisii(Kamenskii, 1901), juveniles fed different levels of carbohydrates

“…Knowledge of the digestive enzyme pattern can reflect some aspects of the nutritional physiology, and this information was applied to determine growth that can also be useful for the diet formulation (Debnath, Pal, Sahu, & Yengkokpam, ; Tongprajjukae & Kovitvadhi, ). Several studies have reported the effects of carbohydrate levels on digestive enzymes in different fish species (Correa, Aguiar, Lundstedt, & Moraes, ; Kumar, Sahu, Pal, & Kumar, ; Tian et al., ; Zhu et al., ), and some studies have been conducted to appraise the nutritional requirements of Kutum. Mahmoodi, Noverian, Falahatkar, and Khoshkholgh () reported that a diet containing 35% protein with 14% lipid would be suitable for optimum growth of Caspian Kutum juveniles.…”