Coupled aquaponics systems

Coupled aquaponics is the archetype form of aquaponics. The technical complexity increases with the scale of production and required water treatment, e.g. filtration, UV light for microbial control, automatic controlled feeding, computerization and biosecurity. Upscaling is realized through multiunit systems that allow staggered fish production, parallel cultivation of different plants and application of several hydroponic subsystems. The main task of coupled aquaponics is the purification of aquaculture process water through integration of plants which add economic benefits when selecting suitable species like herbs, medicinal plants or ornamentals. Thus, coupled aquaponics with closed water recirculation systems has a particular role to fulfil. Under fully closed recirculation of nutrient enriched water, the symbiotic community of fish, plants and bacteria can result in higher yields compared with stand-alone fish production and/or plant cultivation. Fish and plant choices are highly diverse and only limited by water quality parameters, strongly influenced by fish feed, the plant cultivation area and component ratios that are often not ideal. Carps, tilapia and catfish are most commonly used, though more sensitive fish species and crayfish have been applied. Polyponics and additional fertilizers are methods to improve plant quality in the case of growth deficiencies, boosting plant production and increasing total yield. The main advantages of coupled aquaponics are in the most efficient use of resources such as feed for nutrient input, phosphorous, water and energy as well as in an increase of fish welfare. The multivariate system design approach allows coupled aquaponics to be installed in all geographic regions, from the high latitudes to arid and desert regions, with specific adaptation to the local environmental conditions. This chapter provides an overview of the historical development, general system design, upscaling, saline and brackish water systems, fish and plant choices as well as management issues of coupled aquaponics especially in Europe

Hydroponic technologies

This open access book, written by world experts in aquaponics and related technologies, provides the authoritative and comprehensive overview of the key aquaculture and hydroponic and other integrated systems, socio-economic and environmental aspects. Aquaponic systems, which combine aquaculture and vegetable food production offer alternative technology solutions for a world that is increasingly under stress through population growth, urbanisation, water shortages, land and soil degradation, environmental pollution, world hunger and climate change.Hydroponics is a method to grow crops without soil, and as such, these systems are added to aquaculture components to create aquaponics systems. Thus, together with the recirculating aquaculture system (RAS), hydroponic production forms a key part of the aqua-agricultural system of aquaponics. Many different existing hydroponic technologies can be applied when designing aquaponics systems. This depends on the environmental and financial circumstances, the type of crop that is cultivated and the available space. This chapter provides an overview of different hydroponic types, including substrates, nutrients and nutrient solutions, and disinfection methods of the recirculating nutrient solutions

A Field Test of the Relative-Weight-Estimate Method for Determining Herbage Production

Reliable estimates of total herbage yield can be made by the relative-weight-estimate method. The method is based on the concept that it is easier and more accurate to estimate herbage yield as a percent of yield from a base plot than it is to estimate yields directly in grams or pounds. Estimates of total herbage are reasonably accurate, but they are less accurate for vegetation classes of grasses, forbs, and shrubs and for individual species. This method generally contains an inherent bias that cannot be detected unless a double-sampling procedure is used to check and correct field estimates.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Grass -- cafeteria style in southwestern Montana /

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Ommission of dry period or milking once daily affects metabolic status and is reflected by mRNA levels of enzymes in liver and muscle of dairy cows

The objective of this study was to study the mRNA expression of bovine hepatic and muscular genes according to metabolic status in early lactation influenced by different milking regimes. Control-cows (C, n=12) were dried off 56 days before calving and were milked twice daily after parturition. Cows milked once daily (ODM, n=12) were dried off similarly to the C-cows, but were milked only once daily during the first four weeks of lactation. Continuously milked cows (CM, n=12) were milked twice daily throughout the gestation–lactation cycle. Muscle biopsies were obtained within 24 h after calving and at weeks 6 and 16 post partum (pp). Liver biopsies were performed one week before parturition, within 24 h after calving and at weeks 2, 4, and 8 pp. Muscle samples were analyzed for the mRNA abundance of the facilitated glucose transporter, members 1 and 4 (SLC2A1, SLC2A4), the insulin receptor (INSR), lactate dehydrogenase A (LDHA), acyl-CoA dehydrogenase very long chain (ACADVL), enoyl CoA hydratase (ECHS1), and actin alpha 1 (ACTA1). Liver samples were examined for the mRNA abundance of facilitated glucose transporter, member 2 (SLC2A2), carnitine palmitoyltransferase 1A (CPT1A), acyl-CoA dehydrogenase very long chain (ACADVL), glycerol-3-phosphate acyltransferase (GPAM), phosphoenolpyruvate carboxykinase 2 (PCK2), citrate synthase (CS), tyrosine aminotransferase (TAT) and cathepsin L1 (CTSL). In skeletal muscle, transcript abundances of INSR and SLC2A1 were not affected by treatment, whereas SLC2A4 mRNA expression tended to be lower in CM-cows in comparison with C-cows (P=0.07) and ODM-cows (P=0.09). Muscular mRNA levels of LDHA, ACADVL and ACTA1 were not affected by the milking regimen. ECHS1 was down-regulated in CM-cows compared to C-cows (P=0.0009) and in tendency compared to OD-cows (P=0.08). All genes, except ECHS1, were strongly influenced by the sampling time point. In liver samples, metabolic status was reflected by marked changes in various mRNA levels. In CM-cows, higher CPT1A and PCK2 transcript abundances were found compared to C- (P<0.10) and ODM-cows (P<0.05). GPAM-mRNA levels were lowest in ODM cows (P=0.09 and P=0.0003 for comparison with C and CM-cows, respectively). The abundance of CTSL was lowest in C-cows compared with both remaining groups (P<0.05). Additionally, GLUT2, ACADvl, CPT1A, GPAM and PEPCK2 abundances differed between sampling time points. This shows that the improved metabolism was also reflected by changes in muscular and hepatic expression of some key enzymes particularly in CM-cows

Erectile Dysfunction in 45-Year-Old Heterosexual German Men and Associated Lifestyle Risk Factors and Comorbidities: Results From the German Male Sex Study

Background: Erectile dysfunction (ED) is a common public health issue with a significant impact on quality of life. The associations between ED and several risk factors have been reported previously. The continuously increasing incidence of these factors is contributing to the increasing prevalence of ED. Aim: To assess ED prevalence and severity in a representative sample of 45-year-old German men and to analyze the association with risk factors (lifestyle risk factors/comorbidities). Methods: Data were collected within the German Male Sex-Study. Randomly selected 45-year-old men were invited. A total of 10,135 Caucasian, heterosexual, sexually active men were included in this analysis. The self-reported prevalence of ED was assessed using the Erectile Function domain of the International Index of Erectile Function. Risk factors for ED were ascertained using self-report questionnaires. An anamnesis interview and a short physical examination were performed. Main Outcome Measure: ED prevalence and severity were evaluated in a cross-sectional design. The associations of ED with comorbidities (eg, depression, diabetes, hypertension, lower urinary tract symptoms) and lifestyle factors (ie, smoking, obesity, central obesity, physical inactivity, and poor self-perceived health-status) were analyzed by logistic regression. Results: The overall prevalence of ED was 25.2% (severe, 3.1%; moderate, 9.2%; mild to moderate, 4.2%; mild, 8.7%). Among the men with ED, 48.8% had moderate or severe symptoms. ED prevalence increased with the number of risk factors, to as high as 68.7% in men with 5–8 risk factors. In multiple logistic regression with backward elimination, the strongest associations with ED were found for depression (odds ratio [OR] = 1.87), poor self-perceived health status (OR = 1.72), lower urinary tract symptoms (OR = 1.68), and diabetes (OR = 1.38). Conclusion: One out of 4 men already had symptoms of ED at age 45. Almost one-half of the men with ED had moderate to severe symptoms. ED was strongly associated with each analyzed risk factor, and the prevalence and severity of ED increased with an increasing number of risk factors.Hallanzy J, Kron M, Goethe VE, et al. Erectile Dysfunction in 45-Year-Old Heterosexual German Men and Associated Lifestyle Risk Factors and Comorbidities: Results From the German Male Sex Study. Sex Med 2019;7:26–34. Key Words: Erectile Dysfunction, Prevalence, Severity, Risk Factors, Middle-Aged Men, German Male Sex-Stud