scholarly journals Effects of dietary compound acidifiers supplementation on growth performance and intestinal health of juvenile American eels (Anguilla rostrata) cultured in cement tanks

Author(s):  
Mingliang Zhang ◽  
Yue Wang ◽  
Shaowei Zhai
2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 201-201
Author(s):  
Sudario Roberto Silva Junior ◽  
Rhuan F Chaves ◽  
Maíra Resende ◽  
Ygor Henrique De Paula ◽  
Kenio De Gouvêa Cabral ◽  
...  

Abstract Antibiotics growth promoting (AGP) in animal feed has been restricted. With this, several additives have been tested in order to replace AGP and ensure intestinal health. The objective of this study was to evaluate the effects of a blend of additives on growth performance, diarrhea incidence and cecal content microbiota of nursery pigs. A total of 576 weaned pigs (6.21 ± 1.16 kg) were assigned into 4 treatments (12 replicates) in randomized block design: basal diet without additives (NC); basal diet with 120 ppm of halquinol (PC); NC + 0,05% blend of lactic acid (3,5%), benzoic acid (2,5%), flavonoids (3,5%) (B5); NC+ 0,1% of same blend (B10). The pigs were weighed 0 and 42 days into the experiment. On day 10, one animal per pen (10 replicates) was euthanized for microbiota analyses. The diarrhea incidence was calculated by the percentage of visual pens with diarrhea, by day, in the period. The growth performance was analyzed by GLIMMIX procedure and the means were compared with Tukey test (P < 0.050) (SAS, 2009). Diarrhea incidence was analyzed by GENMOD procedure (SAS, 2009). The Kruskal Wallis test was used to compare microbial biodiversity (P < 0.050) by statistical program STAMP. The final weight (P = 0.010) and average daily gain (P = 0.001) of B10 and PC were higher than NC. Regarding diarrhea, it was observed that the B5 and B10 had lower incidence when compared to other groups in the total period. In the microbiome analyses, it was observed that the B5, B10, and PC groups had lower (P = 0.021) biodiversity when compared to the NC piglets. However, the B5 and B10 group had higher biodiversity when compared to the PC group. In conclusion, the supplementation with 0,1% blend of additives can be a substitute for AGP.


2021 ◽  
Vol 13 (14) ◽  
pp. 2671
Author(s):  
Xiaoqin Zang ◽  
Tianzhixi Yin ◽  
Zhangshuan Hou ◽  
Robert P. Mueller ◽  
Zhiqun Daniel Deng ◽  
...  

Adult American eels (Anguilla rostrata) are vulnerable to hydropower turbine mortality during outmigration from growth habitat in inland waters to the ocean where they spawn. Imaging sonar is a reliable and proven technology for monitoring of fish passage and migration; however, there is no efficient automated method for eel detection. We designed a deep learning model for automated detection of adult American eels from sonar data. The method employs convolution neural network (CNN) to distinguish between 14 images of eels and non-eel objects. Prior to image classification with CNN, background subtraction and wavelet denoising were applied to enhance sonar images. The CNN model was first trained and tested on data obtained from a laboratory experiment, which yielded overall accuracies of >98% for image-based classification. Then, the model was trained and tested on field data that were obtained near the Iroquois Dam located on the St. Lawrence River; the accuracy achieved was commensurate with that of human experts.


2021 ◽  
Vol 12 (7) ◽  
pp. 2962-2971
Author(s):  
Yuheng Luo ◽  
Jun He ◽  
Hua Li ◽  
Cong Lan ◽  
Jingyi Cai ◽  
...  

This study was conducted to compare the effect of raw (WB) or mixed fungi-fermented wheat bran (FWB) on the growth, nutrient digestibility and intestinal health in weaned piglets.


2010 ◽  
Vol 88 (11) ◽  
pp. 1121-1128 ◽  
Author(s):  
K. Oliveira ◽  
W. E. Hable

Spawning for the American eel ( Anguilla rostrata (Le Sueur, 1817)) takes place in secretive locations within the Sargasso Sea, which has thus far prevented investigations of gametogenesis and early development in this ecologically and commercially important species. Attempts to induce maturation and reproduction in this species have been few and have produced limited results, with a single report of the production of gastrula-stage embryos. Here we report the successful maturation of female American eels. Maturation occurred within 13 weeks and ovulation was induced with a single injection of 17α,20β-dihydroxy-4-pregnen-3-one (DHP). Following in vitro fertilization, embryogenesis through hatching was observed and larvae were maintained for up to 6 days. We show that a crucial factor for successful fertilization is the stage of the oocyte at the time of induced ovulation. Oocytes that had not reached the migratory nucleus stage, or had passed this stage, were not successfully fertilized. These findings demonstrate that American eel can reproduce in the laboratory and previously untestable hypotheses pertaining to the developmental biology of this elusive species can now be explored.


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