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  • Survey of the environmental impacts of pond fish farming
    19-24
    Views:
    71

    The aim of this study was to survey the nitrogen, phosphorus and organic matter loads and the discharge of fishponds. The inputs and outputs of nutrient amounts of fishponds and their sources are described. The impact of a fishpond on the nutrient loads of receiver waters was determined. The investigations of this study were to determine and evaluate the nitrogen, phosphorus and organic matter budget of fishponds representing different technologies and areas.

  • Experiments on the Nutrient Removal and Retention of an Integrated Pond System
    18-23
    Views:
    183

    A combined intensive-extensive fishpond system developed for the purification and re-use of intensive fishpond effluent water was studied during a three-year experimental period. The investigated pond system consists of five small-size intensive culture ponds of 1 ha total water surface area with 1.5 m water depth and a 20 ha extensive culture pond with 1.0 m average water depth. The water was recirculated between the intensive and extensive ponds with around 60 days retention time in the extensive treatment pond.
    Carbon, nitrogen and phosphorus budget and water purifying capacity were described and evaluated by means of regular measurements of nutrient concentrations in the water and sediment. During the three-year test period, 81.5% of organic carbon, 54.7% of nitrogen and 72.2% of phosphorus were retained by the system as a percentage of the total input of each nutrient. A significant amount of the total nitrogen input was removed by the harvested fish, which was much higher than in traditional fishponds or intensive fish culture systems. The efficiency of nutrient removal is clearly indicated by the 27.3% nitrogen assimilation.
    Only a small percentage of the total nutrient input was discharged into the environment during fish harvest, which was 9.0% for organic carbon, 13.2% for nitrogen and 12.1% for phosphorus. The combination of intensive and extensive fishponds with water recirculation resulted in significant reduction of nutrient discharge into the surrounding aquatic environment, primarily due to the high nutrient processing and retention capacity of the extensive fishpond ecosystem.

  • Investigation of the effect of allithiamine-enriched feed on the poultry gut microbiome composition and resistome
    149-155
    Views:
    66

    Over the past 20–25 years, the poultry industry has evolved into a specific protein production system. However, the stress resulting from intensive rearing practices has led to numerous negative consequences, making the optimisation of livestock gut microbiome composition crucial for mitigating these effects. Advancements in modern molecular biology methods have brought attention to the impacts of nutrients on gut microbiota. In our study, we extensively investigated the changes induced by feed formulations rich in phytonutrients on the gastrointestinal microbiota of livestock using targeted 16S rRNA amplicon sequencing. Our objective is to examine how the developed feed prototype affects the composition of core microbiomes in raised poultry, community diversity, and the resilience of complex microbial networks. We seek correlations between biological livestock and environmental samples to identify which community constituents, in what proportions and occurrences, may play a role in the development of specific diseases. Based on our measurement results, it can be asserted that allithiamine positively modulated "beneficial" community constituents. Beyond the impact of allithiamine-enriched feed rich in phytonutrients, the composition of the microbial community in the poultry gastrointestinal tract is significantly influenced by the age of the birds. Furthermore, due to the presence of multi-drug-resistant pathogens in environmental samples from livestock facilities, appropriate transmission risk management measures are of paramount importance.