上市前限喂对池塘养殖异育银鲫生长及品质的影响

THE EFFECTS OF PRE-HARVEST RESTRICTED FEEDING ON THE GROWTH AND THE PRODUCT QUALITY TRAITS OF POND-REARED GIBEL CARP (CARASSIUS AURATUS GIBELIO)

实验采用5种投喂水平:饱食(R100)、80%饱食(R80)、60%饱食(R60)、40%饱食(R40)、饥饿(R0),旨在探究上市前一个月的池塘养殖中,采用不同程度限喂的投喂策略对异育银鲫生长和品质的影响。结果表明,当投喂水平小于60%,特定生长率(SGR)显著下降,而屠宰率则表现出相反趋势。饥饿组实验鱼呈现出较瘦体形和较硬的肌肉质地。对可能影响肌肉质地的脂肪含量和胶原蛋白总量分析发现,随着投喂水平的降低肌肉脂肪含量显著减少但胶原蛋白总量无显著差异。投喂水平的降低导致鱼体各组织脂肪含量的降低,尤其是内脏脂肪的显著减少。通过SGR与脂肪含量的线性模型,SGR分别解释背肌、腹肌、内脏脂肪含量总变化的56%、66%、71%。在各投喂水平条件下肌肉的粗蛋白含量和必需氨基酸与非必需氨基酸之比维持相对稳定,表明在上市前一个月的池塘养殖中,限喂的方式并未对肌肉的蛋白营养价值造成不良影响。

One-month growth trial was conducted to investigate the effects of different feeding regimes prior to slaughter on the growth and the product quality of pond-reared gibel carp.Five feeding levels were approached：satiation（R100）,80% of satiation（R80）,60% of satiation（R60）,40% of satiation（R40）,and unfed（R0）.The results showed that the specific growth rate（SGR） of gibel carp decreased significantly at the feeding level of 60%.In the contrast,an improved gutted yield was observed at R40 and R0.The unfed fish exhibited a leaner body shape and a harder muscle mass compared to the control group.The lipid content and the total collagen content potentially contribute to muscle textural traits.Analysis on these two factors showed that the lipid content of the muscle reduced significantly whereas there was no difference in the total collagen content.The restricted feeding regime resulted in reduced fat contents in different parts of fish body,especially in the visceral.Relationships between SGR and the lipid content were established using a liner regression model,in which SGR accounted 56% for the dorsal muscle lipid,66% for the ventral muscle lipid,and 71% for the visceral lipid in the total variation.Both the crude protein content and the ratio of essential amino acid to non-essential amino acid were stable in fish at different feeding levels,indicating that the restricted feeding regime did not affect the muscle protein quality in terms of the nutritional value.