Social network analysis of behavioural interactions influencing the development of fin damage in Atlantic salmon (Salmo salar)

The development of fin damage in Atlantic salmon parr was investigated using social network analysis of behavioural interactions occurring under different feeding and stocking conditions. Four separate experiments were carried out in which groups of fish were subjected to a long food restriction period (30 days) described in Chapter 2, high (30 kg/m3) or low (8 kg/m3) fish stocking densities (Chapter 3), predictable or unpredictable food delivery regime (Chapter 4) or a short food restriction period (10 days) described in Chapter 5. Dorsal fin damage (erosion, splits and fin index) was significantly higher in groups of fish subjected to food restriction periods (short and long), held at high stocking density (30 kg/m3) or with an unpredictable food delivery regime. No other fins were found to be affected by fin damage irrespective of the treatment. The social networks based on aggressive interactions showed higher centrality, clustering coefficients, in-degree centrality, out-degree centrality and less dense networks in groups subjected to food restriction (short and long), low stocking densities 8 kg/m3), and unpredictable food delivery. The high centralities and clustering coefficients indicated separation of fish within the groups into initiators of aggression and receivers of aggression. This separation of roles was seen only in the food restricted group, high density groups and unpredictable food delivery groups. Initiators had higher out-degree centrality while receivers showed high in-degree centrality. Also, initiators of aggressive interactions had less fin erosion, higher final weights and higher body lengths than receivers of aggression. The severity of fin damage was significantly higher when this role differentiation occurred, and it was highly correlated with fin biting events. Additionally, overall aggression was higher in food restricted groups, low density groups and unpredictable groups. The dynamic analyses of networks over time (Chapter 6) showed that fish classified as initiators of aggression did not change this behaviour after normal/control environmental conditions were restored (i.e. ad libitum food delivery, low stocking density or predictable food delivery). The latter result indicates that individual fish maintained their behaviour irrespective of their social context, which is consistent with the definition of behavioural syndromes, personalities or temperament defined for other non-human animals. Overall these studies demonstrated the importance of using social network analysis to clearly identify and quantify roles that individual fish assume within their network group and through time based on their behavioural interactions leading to dorsal fin damage and differential physical characteristics. The results are potentially applicable within the commercial aquaculture industry as a valuable technique to evaluate and improve the welfare of farmed fish

Evaluación de Cortisol sanguíneo como indicador de Bienestar Animal antes, durante y posterior a rodeos en Caballos Criollos Chilenos

El rodeo en Chile es una actividad donde participan equinos y bovinos, y tiene un potencial de generar estados desmejorados de bienestar animal. Estos estados desmejorados están relacionados principalmente a traumas músculo-esqueléticos en ambas especies. En el caso de los equinos fina sangre chilenos esto se relaciona al dolor por patologías de articulaciones en carpo y tarso debido a la forma oblicua anormal del trote y carrera durante el entrenamiento y competencia. Actualmente, la legislación chilena sobre protección animal deja fuera a animales utilizados en deportes como equinos y novillos, y se desconoce el efecto de este tipo de actividad sobre el bienestar de los animales, incluido stress fisiológico. El presente estudio midió niveles de cortisol y glucosa sanguínea antes, durante y después de una competencia de rodeo

Evaluación de cortisol sanguíneo como indicador de bienestar animal antes, durante y posterior a rodeos en equinos criollos fina sangre chilenos

Comunicación científica en formato E- PÓSTER, realizada en las III Jornadas Internacionales de Investigación, Ciencia y Universidad y las XII Jornadas de Investigación UMaza, en el Bloque de comunicaciones científicas: "MEDICINA VETERINARIA EN EL ÁMBITO PECUARIO Y SALÚD PÚBLICA", el mismo fue moderado por el DR. BOTTINI RUBÉN. Las jornadas se llevaron adelante desde 19 al 23 de octubre del 2020 en formato totalmente virtual bajo plataforma Zoom y fueron transmitidas por el canal YouTube de la UMaza y el Facebook del Área de Ciencia y Técnica UMaza (Somos Ciencia y Técnica UMaza)

Evaluating the Effects of a Short-Term Feed Restriction Period on the Behavior and Welfare of Atlantic Salmon, Salmo salar, parr Using Social Network Analysis and Fin Damage

Social network analysis (SNA) was used to quantify the role of behavioral interactions on the frequency and severity of fin damage in Atlantic salmon, Salmo salar, parr subjected to a short feed restriction period of 10 d. Dorsal fin erosion was observed in both feed‐restricted (FR) and control (C) groups of fish, but was significantly more frequent and severe in FR groups. FR fish had a significantly lower weight, length, and poorer body condition in comparison to C groups. Social networks based on aggressive interactions showed significantly higher overall degree‐centrality, clustering coefficients, out and in‐degree centralities in FR groups. This led to the formation of clusters of fish into initiators and receivers of aggression. Only the receivers of aggression exhibited dorsal fin damage, while initiators did not. Initiators and receivers of aggression in FR groups retained their roles even after control conditions were restored, suggesting that short periods of feed restriction can lead to permanent modifications in aggressive behavior. This study demonstrates the applied value of using SNA to investigate the longer term effects that aggressive behavioral interactions have on fin damage and welfare in Atlantic salmon.We thank all the members of staff at the Aquaculture Research Station in Tromsø for their technical help and support during the experiment. Hernán A. Cañon Jones was sponsored by a Chevening Scholarship from the Foreign Commonwealth Office of the British Government and managed by the British Council, Cambridge Overseas Trust and the National Science and Technology Commission of the Government of Chile/Comisión Nacional de Investigación Científica y Tecnológica del Gobierno de Chile (CONICyT), and by Becas Chile Scholarship from CONICyT of the Government of Chile. Substantive additional financial support was received from Nofima, project 172487/S40, COST Action 867: Welfare of fish in European aquaculture, Magdalene College Research Fund and Cambridge Philosophical Society.This is the author accepted manuscript. The final version is available from Wiley via https://doi.org/ 10.1111/jwas.1232

Behavioural indicators of welfare in farmed fish

Behaviour represents a reaction to the environment as fish perceive it and is therefore a key element of fish welfare. This review summarises the main findings on how behavioural changes have been used to assess welfare in farmed fish, using both functional and feeling-based approaches. Changes in foraging behaviour, ventilatory activity, aggression, individual and group swimming behaviour, stereotypic and abnormal behaviour have been linked with acute and chronic stressors in aquaculture and can therefore be regarded as likely indicators of poor welfare. On the contrary, measurements of exploratory behaviour, feed anticipatory activity and reward-related operant behaviour are beginning to be considered as indicators of positive emotions and welfare in fish. Despite the lack of scientific agreement about the existence of sentience in fish, the possibility that they are capable of both positive and negative emotions may contribute to the development of new strategies (e. g. environmental enrichment) to promote good welfare. Numerous studies that use behavioural indicators of welfare show that behavioural changes can be interpreted as either good or poor welfare depending on the fish species. It is therefore essential to understand the species-specific biology before drawing any conclusions in relation to welfare. In addition, different individuals within the same species may exhibit divergent coping strategies towards stressors, and what is tolerated by some individuals may be detrimental to others. Therefore, the assessment of welfare in a few individuals may not represent the average welfare of a group and vice versa. This underlines the need to develop on-farm, operational behavioural welfare indicators that can be easily used to assess not only the individual welfare but also the welfare of the whole group (e. g. spatial distribution). With the ongoing development of video technology and image processing, the on-farm surveillance of behaviour may in the near future represent a low-cost, noninvasive tool to assess the welfare of farmed fish.Fundação para a Ciência e Tecnologia, Portugal [SFRH/BPD/42015/2007]info:eu-repo/semantics/publishedVersio

Effect of sitagliptin on cardiovascular outcomes in type 2 diabetes

BACKGROUND: Data are lacking on the long-term effect on cardiovascular events of adding sitagliptin, a dipeptidyl peptidase 4 inhibitor, to usual care in patients with type 2 diabetes and cardiovascular disease. METHODS: In this randomized, double-blind study, we assigned 14,671 patients to add either sitagliptin or placebo to their existing therapy. Open-label use of antihyperglycemic therapy was encouraged as required, aimed at reaching individually appropriate glycemic targets in all patients. To determine whether sitagliptin was noninferior to placebo, we used a relative risk of 1.3 as the marginal upper boundary. The primary cardiovascular outcome was a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for unstable angina. RESULTS: During a median follow-up of 3.0 years, there was a small difference in glycated hemoglobin levels (least-squares mean difference for sitagliptin vs. placebo, -0.29 percentage points; 95% confidence interval [CI], -0.32 to -0.27). Overall, the primary outcome occurred in 839 patients in the sitagliptin group (11.4%; 4.06 per 100 person-years) and 851 patients in the placebo group (11.6%; 4.17 per 100 person-years). Sitagliptin was noninferior to placebo for the primary composite cardiovascular outcome (hazard ratio, 0.98; 95% CI, 0.88 to 1.09; P<0.001). Rates of hospitalization for heart failure did not differ between the two groups (hazard ratio, 1.00; 95% CI, 0.83 to 1.20; P = 0.98). There were no significant between-group differences in rates of acute pancreatitis (P = 0.07) or pancreatic cancer (P = 0.32). CONCLUSIONS: Among patients with type 2 diabetes and established cardiovascular disease, adding sitagliptin to usual care did not appear to increase the risk of major adverse cardiovascular events, hospitalization for heart failure, or other adverse events

Identification and Validation of Operational Welfare Indicators Appropriate for Small-Scale Goat Farming in Chile

Goat production in Chile is carried by small-scale farmers obtaining milk and cheese as the main products. The welfare of goats under these types of production systems is currently unknown and no appropriate validated operational welfare indicators are currently available. We took the tasks of identifying operational welfare indicators and validating them with all stakeholders. A total of 37 operational welfare indicators were obtained. The use of these validated indicators and the welfare score is appropriate to Chilean goat production systems and may successfully increase the sustainability of production and farmers in Chile

Quillaja saponaria (Molina) Extracts Inhibits In Vitro Piscirickettsia salmonis Infections

P. salmonis infections are the cause of major bacterial disease in salmonids in Chile, and the reason for using more antibiotics compared to other salmon-producing countries. Vaccination and antibiotics have not been efficient and new approaches are needed. The safety of Quillaja saponaria extracts was measured by cytotoxicity using flow cytometry of cytopathic and death of fish cell cultures and efficacy was assessed using in vitro infection models with pathogenic P. salmonis. Cytotoxicity was low and control of in vitro infections was achieved with all products, with protection of over 90%. Minimum inhibitory concentrations were much higher than those in the infection using cell cultures. These results suggest a dual mechanism of action where less purified extracts with a combination of saponin and non-saponin components simultaneously decrease P. salmonis infection while protecting cell lines, rather than exerting a direct antimicrobial effect. Quillaja saponins controlled in vitro infections with P. salmonis and could be considered good candidates for a new, safe and sustainable method of controlling fish bacterial infectious diseases