Effects of dietary magnesium on the growth, carapace strength and tissue magnesium concentrations of soft-shelled turtle,Pelodiscus sinensis(Wiegmann)

Abstract

A feeding trial was conducted to evaluate the effects of dietary magnesium on the growth, carapace strength, tissue and serum Mg concentration of soft‐shelled turtles, Pelodiscus sinensis (Wiegmann). Juvenile soft‐shelled turtles of approximate 5.4 g body weight were fed diets with seven levels of Mg (48, 206, 369, 670, 955, 1195 and 1500 mg Mg kg−1) for eight weeks. No significant difference (P ≥ 0.05) was found in weight gain (WG), feed conversion ratio or protein efficiency ratio among treatments. However, the WG of turtles continued to increase with increasing dietary Mg levels up to 670 mg kg−1, beyond which the WG levelled off. The plasma alkaline phosphatase activity and the muscle, bone Mg concentrations of the turtles increased with the increasing dietary Mg levels between 48 and 955 mg kg−1, beyond which the tissue Mg concentrations remained relatively constant. Furthermore, the carapace strengths of turtles fed with the control diet of 48 mg Mg kg−1 were significantly weaker (P < 0.05) than that of turtles fed with diets containing higher Mg levels. Based on a broken‐line modelling analysis, the required dietary Mg level for the optimal WG of juvenile soft‐shelled turtles was estimated to be approximately 650 mg kg−1. By contrast, the required dietary Mg levels for turtles to reach the optimal muscle and bone Mg concentrations were 1050 and 1000 mg kg−1 respectively. The required dietary Mg level for maximal alkaline phosphatase activity was approximately 980 mg kg−1.

Supplementation with turmeric residue increased survival of the Chinese soft-shelled turtle (Pelodiscus sinensis) under high ambient temperatures

“…The Chinese soft-shelled turtle (SST), Pelodiscus sinensis (Wiegmann), is an important member of the reptilian aquaculture with high nutritional and medicinal value (Chen et al, 2014). SST has been widely used as a nutraceutical for treating diabetes, the menopause, hypertension, and anemia, and other chronic diseases in China (Chen CY and Huang, 2015). On the China mainland, 285 900 tons of SSTs were produced and consumed in 2012 (Chen CY and Huang, 2015).…”

“…SST has been widely used as a nutraceutical for treating diabetes, the menopause, hypertension, and anemia, and other chronic diseases in China (Chen CY and Huang, 2015). On the China mainland, 285 900 tons of SSTs were produced and consumed in 2012 (Chen CY and Huang, 2015). However, the SST is suffering from unhealthy farming practices, such as the use of chemical drugs, high-density culturing, and environmental pollution, resulting in significant reduction in both quality and quantity, high mortality rate, and serious economic losses in aquatic farming.…”

Estimation of dietary vitamin K requirement of juvenile Chinese soft‐shelled turtle,Pelodiscus sinensis

“…The strength of the turtle carapace was determined using a procedure that we have developed (Chen & Huang, ; Chou & Huang, ; Wang & Huang, ). A Rheo Tex rheometer (Sun Scientific, Tokyo, Japan) equipped with a spherical probe was used.…”

Impacts of dietary protein on growth performance, feed utilization, amino acid profile, activities of digestive and amino acid metabolizing enzymes of the soft‐shelled turtle ( Pelodiscus sinensis )

“…Previous studies have described the dietary starch (Kou et al, 2018; Zhang et al, 2019), vitamin C and E (Huang & Lin, 2004; Zhou et al, 2004), lipid (Huang et al, 2005; Lin & Huang, 2007), iron (Chu et al, 2007), zinc (Huang et al, 2010), magnesium(Chen et al, 2014; Chen & Huang, 2013), calcium and phosphorus (Huang et al, 2003) requirements of soft‐shelled turtles, but conflicting protein requirements have been reported. The levels of protein ranged from 42% to 47% in feeds of soft‐shelled turtles (Nuangsaeng & Boonyaratapalin, 2001; Zhou et al, 2013).…”