Growth and Muscle Quality of Grass Carp (Ctenopharyngodon idella) in In-Pond Raceway Aquaculture and Traditional Pond Culture

Abstract

In-pond raceway aquaculture (IPRA) is the rational prescription for water eutrophication and improves the pond environment, enhancing production and the quality of fish. This experiment explored the growth performances and muscle quality of grass carp with stocking densities of 32 tail/m3 and 0.07 tail/m2 in IPRA and traditional pond culture (TPC), respectively. The hepatosomatic index, visceral mass ratio, and correction factor were statistically similar in IPRA compared to TPC. While the weight gain rate (p < 0.001) and the content of crude lipid (p < 0.05) in the flesh of grass carp were observed to be statistically promising in IPRA, the pH and water holding capacity, as well as hardness and chewiness, in grass carp muscle were not significantly different between the two culture systems. However, the 2-MIB concentration in the muscle was observed to increase continuously for the complete culture period in IPRA. The abundance of Proteobacteria was found to be higher in TPC (p < 0.05), while the richness of Planctomycetes was superior in IPRA (p < 0.05). Despite the high stocking density, the off-flavor in IPRA-produced grass carp had less of an impact on the flesh aesthetic quality compared to TPC. Considering all these facts, the results of this study show that grass carp with a better muscle quality can be produced from IPRA.

Comparative Analysis of Nutritional Quality, Serum Biochemical Indices, and Visceral Peritoneum of Grass Carp (Ctenopharyngodon idellus) Fed with Two Distinct Aquaculture Systems

“…However, the ash content in the IPRS group was notably lower than in the TPI group (p < 0.01), while the crude lipid content was significantly higher in the IPRS group compared to the TPI group (p < 0.05). These findings are consistent with Gharti's result, who reported increased crude lipid levels in grass carp raised in raceways, which is also in line with the results of Hai-Shan, where the crude lipid content in gibel carp (Carassius auratus gibelio) muscle significantly increased after swimming training [16,31]. The fundamental reason for the differences in nutritional content between aquaculture modes lies in the variation in food and environment [32].…”

“…During TPI mode, grass carp consume grass and other natural food, leading to reduced muscle fat levels and increased moisture levels. The decreased fat levels are linked to the heightened activity and vigilance of grass carp in pond intercropping, as stated in Gharti's study [16]. The higher fat content in the IPRS group leads to smoother muscle; if the fat content is lower, the muscle becomes coarser, reducing palatability [30].…”

“…Various methods are used for cultivating it, such as pond culture, polyculture, freshwater pond culture, cage culture, reservoir culture, paddy field culture, and traditional integrated breeding and farming modes. Among these, traditional pond culture is predominant, yet it tends to reduce the quality, texture, and market value of the fish flesh, leading to a muddy taste and soft muscle [16]. Additionally, the quality of traditional pond culture is hard to guarantee due to poor infrastructure and severe environmental pollution [17].…”