Pre‐soaking of the feed pellets: a trick for successful feed utilization in juvenile green turtles (Chelonia mydas Linnaeus, 1758)

Abstract

Pre-soaking of the feed pellets in water can improve feed utilization in juvenile green turtles (Chelonia mydas Linnaeus, 1758), but the pre-soaking has not previously been optimized. This study aimed to optimize the water amount used for pre-soaking the pellets. The experiments followed a completely randomized design with three replications of each dietary treatment group. Initially 10-day-old green turtles (20-22 g body weight) were treated in an indoor aquaculture system for 3 months. The dietary treatment pellets were pre-soaked with 0.3, 0.5 or 0.7 (v/w) relative amounts of water that are here termed soaking ratios. At the end of experiment, there were no significant differences in survival (96% on average) and growth (average body weight 75.34 g and specific growth rate 2%/day, on average) of turtles in three dietary treatments (p > 0.05). Feed utilization was the best in turtles fed with 0.7 pre-soaked ratio, as indicated by significant reductions (p < 0.05) in the feeding rate (7.44% body weight/day) and the feed conversion ratio (1.12 g feed/g gain). Digestion was also improved by the induction of faecal digestive enzymes as well as the faecal thermal properties. The rapid growth did not negatively affect the general haematological parameters of reared turtles. These findings indicate that the pre-soaking of feed pellets at the optimal soaking ratio (1:0.7 w/v of pellet to water) can contribute through improved feed utilization of green turtles.

Effect of organic acids or probiotics alone or in combination on growth performance, nutrient digestibility, enzyme activities, intestinal morphology and gut microflora in broiler chickens

“…That there were no significant ( p > .05) effects of dietary supplementation on feed utilization (FI and FCR) was supported by the unchanged excreta thermal parameters ( T o , T c , T p , T c – T o and ΔH). The presence of transition peaks in the low‐temperature range indicates that available constituents remained in the excreta after digestion and absorption (Kanghae et al., ), indicating a similar capacity to utilize feed and excrete equal amounts of indigestible elements in the excreta. Moreover, the findings in the current study in relation to the thermal properties were in agreement with the findings related to the digestibility of nutrients and digestive enzyme activity.…”

“…Therefore, nutritional investigations for the development of poultry feed by studying the excreta thermal properties are suitable. This alternative technique is simple, reliable and less time‐consuming for distinguishing the differences in nutritional response of reared animals (Kanghae et al., ; Wattanakul et al., ). This non‐invasive approach is also appropriate for use in other species without ethical concerns.…”

“…Digestible (low temperature) and indigestible (high temperature) elements after digestion and absorption were monitored by the thermal properties of the excreta (Kanghae et al., ; Wattanakul, Thongprajukaew, Songnui, Satjarak, & Kanghae, ). Fresh broiler excreta ( n = 5 per treatment) was collected from trays during the last 3 days prior to the end of the experiment.…”

Optimal-rearing density for head-starting green turtles (Chelonia mydasLinnaeus, 1758)

“…Based on protection by IUCN, CITES and in Thailand's Wildlife Preservation and Protection Act, only non‐invasive techniques without ethical concerns were used to evaluate the turtles’ responses to various stocking densities. Nutritional investigation and health statuses were assessed though the fecal digestive enzymes [Córdova‐Murueta et al, ; Kanghae et al, , ] and hematological parameters [Christopher et al, ; Tavares‐Dias et al, ]. The findings from this study could be used to improve the head‐starting programs of green turtles in the government sector, as well as in the public displays in zoos or aquaria, ultimately enhancing or augmenting wild population of green turtles worldwide.…”

Faecal characteristics as markers of Chelonia mydas feeding

“…The characteristics relating to enzymatic hydrolysis, in vitro and probably also in vivo, include microstructure, thermal transition properties, and crystallinity [10][11][12][13] . As the hydrolysis directly affects digestion and absorption along the alimentary tract, these physicochemical characteristics of feed impact feed utilization, as well as the digestion of feed by the digestive enzymes observable in the faeces 1,2 . The main objective of this study was to evaluate whether digestive enzymes present in turtle faeces, as well as faecal physicochemical characteristics, can be used to predict feed utilization.…”