Effects of spray-dried animal plasma on growth performance, survival, feed utilization, immune responses, and resistance to Vibrio parahaemolyticus infection of Pacific white shrimp (Litopenaeus vannamei).

Spray-dried animal plasma (SDP) in feed for several animal species provides health benefits, but research about use of SDP in shrimp feed is very limited. The objectives of the present study were to investigate the effects of dietary SDP on growth performance, feed utilization, immune responses, and prevention of Vibrio parahaemolyticus infection in Pacific white shrimp (Litopenaeus vannamei). In Experiment 1, the post-larvae were divided into five groups (four tank/group and 80 shrimp/tank) and fed four times daily diets with porcine SDP at 0, 1.5, 3, 4.5, and 6% of the diet for 45 days. In Experiment 2, the surviving shrimp from Experiment 1 were redistributed into six groups: four SDP groups as in Experiment 1 plus the positive and negative controls (four tank/group and 30 shrimp/tank). They were then challenged with V. parahaemolyticus by immersion at 105 colony-forming units (CFU)/mL and were fed with the same diets for another 4 days. In Experiment 1, shrimp fed 4.5% or 6% SDP diets had significantly higher body weight, survival rate, and improved feed conversion ratio. The immune parameters (total hemocyte count and phagocytic, phenoloxidase, and superoxide dismutase activities) of the shrimp fed 3-6% SDP diets also showed significant enhancement compared to the control. In Experiment 2, the survival rates of the 3-6% SDP groups were significantly higher than the positive control at day 4 after the immersion challenge. Likewise, the histopathological study revealed milder signs of bacterial infection in the hepatopancreas of the 3-6% SDP groups compared to the challenged positive control and 1.5% SDP groups. In conclusion, shrimp fed diets with SDP, especially at 4.5-6% of the diet, showed significant improvement in overall health conditions and better resistance to V. parahaemolyticus infection.

Effects of isoquinoline alkaloids from Macleaya cordata on growth performance, survival, immune response, and resistance to Vibrio parahaemolyticus infection of Pacific white shrimp (Litopenaeus vannamei).

Isoquinoline alkaloids (IQs) from Macleaya cordata are promising natural products for enhancing the growth performance and overall health condition of farmed animals. The present study aimed to investigate the effects of two formulas of IQ extract, provided in either a powdered formula (IQ-E) or a water-soluble, granulated formula (IQ-WS) and containing the main active component sanguinarine at a concentration of 0.5% and 1%, respectively, on the growth, survival, immune response, and resistance to Vibrio parahaemolyticus infection of Pacific white shrimp (Litopenaeus vannamei). In Experiment 1, the postlarvae were divided into five groups (four replicates/group and 100 shrimp/tank) and fed four times/day for 30 days with a control feed, IQ-E at 200 or 300 mg/kg of feed, or IQ-WS at 100 or 150 mg/kg of feed. In Experiment 2, the surviving shrimp from Experiment 1 were redistributed into six groups (four treatment groups as in Experiment 1 plus the positive and negative controls with four replicates/group and 30 shrimp/tank) and challenged with V. parahaemolyticus by immersion at a concentration of 103 colony-forming units (CFU)/mL and were fed with the same diets for another 14 days. The results revealed that all IQ-fed shrimp in Experiment 1 had significantly enhanced survival rates and immune parameters (total hemocyte count and phagocytic, phenoloxidase, and superoxide dismutase activities) compared to the control group, even though the growth performances were similar across all groups. In Experiment 2, all IQ-fed groups showed better growth performance and survival rates compared to the positive control. Other than in the positive control group, no histopathological lesions in the hepatopancreas and the intestine were found. In summary, the current study demonstrated the benefits of using IQs from M. cordata as feed additives for improving the growth performance, survival rate, immune responses, and resistance to vibriosis of Pacific white shrimp.

Effect of teapot materials on the chemical composition of oolong tea infusions.

BACKGROUND: The flavor and quality of tea are widely believed to be associated with the pot in which the tea is made. However, this claim is mostly by experiences and lacks solid support from scientific evidence. The current study investigated and compared the chemical compositions of oolong tea made with six different teapot materials, namely Zisha, Zhuni, stainless steel, ceramic, glass and plastic. RESULTS: For each tea sample, polyphenols and caffeine were examined by HPLC-UV, volatile compounds by GC/MS, amino acids by LC/MS and minerals by ICP-MS. The results suggested that tea infusions from Zisha and Zhuni pots contain higher levels of EGC, EGCG and total catechins and less caffeine than those from ceramic, glass and plastic pots and tend to have the lowest total mineral contents, potassium and volatile compounds in tea soup. The statistical differences were not all significant among Zisha, Zhuni and stainless steel pots. CONCLUSION: Based on the overall chemical composition of the tea infusion, Yixing clay pots (Zisha and Zhuni) produce tea infusions that are presumably less bitter and more fragrant and tend to contain more healthful compounds than tea infusions from other pots. The results could partially explain why Yixing clay pots are among the most popular teapots. The beneficial effects of long-term repeated use of these teapots warrants further study. © 2017 Society of Chemical Industry.