Effect of farming patterns on the nutrient composition and farming environment of loach, Paramisgurnus dabryanus

Abstract

This study aimed to investigate the effect of farming patterns on the farming environment and nutrient composition of loach Paramisgurnus dabryanus. Loach juveniles (2.57 ± 0.42 g) grown for 150 days were stocked with two treatments: high-density farming pattern (210 ind·m−2) and imitative ecological farming pattern (70 ind·m−2). At the end of the farming experiment, the nutrient composition of the loach dorsal meat, the water quality, and the sediment in both farming patterns were determined. The contents of chemical oxygen demand, nitrite nitrogen, heterotrophic bacteria, denitrifying bacteria and organic carbon in the imitative ecological ponds were significantly lower than those in the high-density groups (P < .05), whereas the two treatments presented no significant difference in the proximate content of loach (P > .05). In addition, the two treatments displayed no significant difference in the unsaturated fatty acid and saturated fatty acid contents of loach (P > .05). The ratios of essential amino acids to total amino acids and of delicious amino acids to total amino acids of loach under the two treatments did not significantly differ (P > .05). The results indicated that although the nutrient compositions of the high-density and imitative ecological cultured loaches did not vary significantly, the high-density farming pattern influenced the water quality and the sediment.