Effects of two processing methods of Sesuvium portulacastrum diet on culture performance,nutrient composition,and muscle texture properties of Haliotis discus hannai
The increase in feed costs has significantly impacted the sustainable development of the Chinese abalone industry. The halophyte sea purslane (Sesuvium portulacastrum) is nutritionally valuable and shows potential as a novel bait source for abalone. We analyzed the nutrient composition of blanched and salted sea purslane to assess the value of sea purslane as abalone feed. Subsequently,blanched and salted sea purslane were separately used as the sole feed for Pacific abalone (Haliotis discus hannai) with the same specifications in each group (shell length:5.161±0.315 cm,body weight:16.90±3.07 g). The red alga Gracilaria lemaneiformis served as the control feed. The abalone were feed once every 4 days over an 80-day culture cycle,with sufficient feed dispensed each time to ensure the provision of adequate feed and the generation of leftovers. There were four main findings. First,moisture,energy,crude protein (dry basis),crude fat,carbohydrate,and ash contents were (89.08±0.01)％,(103.44±0.15) kJ/100 g,(12.49±0.28)％,(2.93±0.06)％,(20.34±0.28)％,and (29.10±0.08)％,respectively,for blanched sea purslane and (59.37±0.04)％,(139.38±0.79) kJ/100 g,(4.16±0.08)％,(1.25±0.01)％,(5.74±0.18)％,and (72.80±0.05)％,respectively,for salted sea purslane. Both types of sea purslane feed contained 18 amino acids,indicating a comprehensive amino acid profile that was relatively close to that of Pacific abalone muscle in terms of the presence of 11 important amino acids. Second,the two types of sea purslane feed significantly influenced the feed intake (FI) and feed conversion ratio (FCR) of Pacific abalone (P<0.05). The FI and FCR were highest in abalone that fed on salted sea purslane and lowest in abalone that fed on G. lemaneiformis. Neither type of sea purslane feed significantly influenced the survival rate,average daily shell length gain,average daily body weight gain,specific growth rate of shell length,specific growth rate of body weight,condition factor,or meat yield of Pacific abalone (P>0.05). Third,both types of sea purslane feed significantly increased the ash content and reduced the moisture,collagen,and total amino acid contents of Pacific abalone muscle (P<0.05);however,they did not significantly influence the crude fat content,essential amino acids/total amino acids ratio,first limiting amino acid content(P>0.05). The sea purslane feed could increase the linoleic acid and α-linolenic contents of Pacific abalone muscle. Fourth,there were no significant differences in the influence of the two types of sea purslane feed on the springiness and resilience of Pacific abalone muscle tissue (P>0.05). However,blanched sea purslane significantly reduced the hardness and chewiness of the muscle tissue (P<0.05),while salted sea purslane significantly increased the hardness of the muscle tissue (P<0.05). In conclusion,both types of sea purslane feed can replace G. lemaneiformis as feed for Pacific abalone within an 80-day culture cycle. Pacific abalone fed with sea purslane had good production performance and nutritional value,with salted purslane contributing to improved abalone muscle texture.
万方数据
维普
