Effects of Dietary Xanthophyll Supplementation on Growth Performance, Body Color, Carotenoids, and Blood Chemistry Indices of Chinese Soft‐Shelled Turtle Pelodiscus sinensis

Abstract

A 12-week experiment was conducted to investigate the effects of diets containing 0 (CD), 40 (X1), 80 (X2), and 120 mg/kg (X3) xanthophyll on the growth, body color, and blood chemistry of the Chinese soft-shelled turtle Pelodiscus sinensis. Four hundred and eighty turtles with initial weight of 37.90 AE 0.26 g were randomly stocked equally in 12 cement ponds (4.0 × 5.0 × 0.8 m) to form four groups in triplicate. The turtles were fed one of the four diets (crude protein 48%, crude lipid 6%) twice daily, with the feed amount set at 3% of their total body weight. The results indicated that the supplement of 80 mg/kg xanthophyll in the diet had the most significant effect on growth, feed conversion ratio, and amino acid content in muscle tissue. The yellowness of the carapace and the plastron skin increased with higher xanthophyll levels. Moreover, the final yellowness in the plastron skin was higher than the initial yellowness. The carotenoid content in the liver and carapace was significantly enhanced with increasing xanthophyll levels and showed a significant linear correlation with the dietary xanthophyll supplement levels. The liver carotenoid content in the X2 and X3 groups and carapace skin carotenoid content in the X3 group were markedly higher than were those in turtles that were fed the control diet (P < 0.05). Compared with the control diet, adding xanthophyll significantly increased acid phosphatase activity in serum while obviously lowering the alanine aminotransferase activity. The triglyceride and total cholesterol content decreased with increases in xanthophyll. There were no significant differences in the serum superoxide dismutase and glutathione peroxidase activity in animals that received the xanthophyll-supplemented and control diets. The current study results suggest that the growth performance and skin coloration of Chinese soft-shelled turtle can be improved by including 80-120 mg/kg xanthophyll in the diet.

Effect of dietary canthaxanthin and xanthophyll on growth, antioxidant capacity, body colour, and BCO2 , CAT and SOD2 gene expression in Chinese soft‐shelled turtle ( Pelodiscus sinensis )

“…Studies also showed that adding lutein (70.3-239 mg/ kg) can promote SGR of Chinese soft-shelled turtles (4.81 ± 0.04 g) (Liu et al, 2013), and the optimal β-carotene level for turtle growth (mean weight: 5.7 g) was 49.1 mg/kg (Chen & Huang, 2011). Our previous research suggested that 80-120 mg/kg xanthophyll and 8% spirulina in the diet have an effective influence on the growth performance of turtles (He et al, 2019;Wang et al, 2020). However, studies in some kinds of fishes indicated that supplementation with carotenoids in feed had no effect on the growth (Shi et al, 2010;Yeşilayer et al, 2020, Abd El-Gawad et al, 2019.…”

“…While the canthaxanthin ratio or canthaxanthin supplementation in feed and carotenoid content in the liver and plastron had no significant linear relationship. In a previous study, it was shown that there was a linear relationship between carotenoid contents in the liver and carapace skin and xanthophyll supplementation in feed (Wang et al, 2020).…”

“…Studies have shown that adding carotenoids such as xanthophyll (Liu et al, 2013;Wang et al, 2020), corn gluten meal (Zhang, 2013) and spirulina (Ning et al, 2000) to feed can improve the body colour of soft-shelled turtle. Nevertheless, the effect of red carotenoids in turtle has not been studied so for.…”

Expression and Characterization of the Spats1 Gene and Its Response to E2/MT Treatment in the Chinese Soft-Shelled Turtle (Pelodiscus sinensis)

“…This implies that the differential expression of Spats1 in different ages may be closely associated with the expression of testosterone. In addition, spermatogenesis of P. sinensis is initiated in the summer (June), and the mature spermatozoa are subsequently released from the epididymis in the autumn (October) [ 6 , 43 ]. In P. sinensis , the seminiferous epithelium is spermatogenically active in summer and autumn, but quiescent during the remaining part of the year [ 43 ].…”

“…P. sinensis is an important species of aquaculture which is broadly spread in Asia. Since the fast growth of turtle farming, the economic value of P. sinensis has also increased [ 6 ]. Phylogenetic analysis revealed that P. sinensis is a relatively ancient tetrapod, and the study of the morphological evolution and reproductive patterns of the species is of great scientific value [ 7 , 8 ].…”