Modelling the Effect of Maize Silage and Winter Oat Forage Crop on Cow-Calf Systems in Argentina

Cow-calf systems in the flooding Pampa - Argentina, are facing increasing competition with cropping systems for resources and land. In this context, to be more competitive livestock systems require system intensification, which demands an improvement on the feedbase. Forage crops and feeding silage have been used widely on dairy and beef cattle finishing systems. The purpose of the study was to assess with a model the level of intensification that can be achieved in cow calf systems and its economic effects by incorporating maize silage and winter grazing oat crops

Efecto de la gestión integral del estiércol en un sistema feedlot : modelación productiva y gases de efecto invernadero

Kazlauskas Kong, Leyli Giselle. Beca EVC-CIN.Bilotto, Franco. Universidad de Tandil. Facultad de Ciencias Veterinarias. Centro de Investigación Veterinaria de Tandil (CIVETAN). Tandil, Buenos Aires, Argentina.Fernandez Rosso, Catalina. Universidad de Tandil. Facultad de Ciencias Veterinarias. Centro de Investigación Veterinaria de Tandil (CIVETAN). Tandil, Buenos Aires, Argentina.Ferrati, Rosana. Instituto Multidisciplinario sobre Ecosistemas y Desarrollo Sustentable (UNCPBA- CIC). Buenos Aires, Argentina.Machado, Claudio F. Universidad de Tandil. Facultad de Ciencias Veterinarias. Centro de Investigación Veterinaria de Tandil (CIVETAN). Tandil, Buenos Aires, Argentina.136-150El stock de ganado bovino en la Argentina es de 54,5 millones de cabezas, con una participación creciente de los sistemas “feedlot”. El objetivo de este trabajo es cuantificar las emisiones de gases de efecto invernadero de un sistema “feedlot” mediante el desarrollo de un modelo dinámico productivo que permite analizar el efecto del barro sobre el consumo y la ganancia de peso vivo (GPV) en diferentes condiciones climáticas, las posibles instancias de mitigación a partir del manejo del estiércol, incluyendo su aplicación como fertilizante natural, y la incidencia de las emisiones provenientes de la producción del alimento en el cálculo de emisiones totales. Se consideró un “feedlot” base de 2500 animales con dos ciclos consecutivos. La intensidad de emisión del “feedlot” fue de 3,6 kg CO2.Eq. kg-1 producido, proveniente por el 42,7% del alimento, 30,3% de la fermentación entérica, 22,5% del estiércol y 4.5% del mantenimiento del mismo. El efecto barro en condiciones de humedad media y alta aumentó en 0,8 y 5,4% las emisiones de GEI respecto de la condición moderada cuando se realizó limpieza del corral luego de finalizado el ciclo. En condiciones de humedad media y considerando dos ciclos sin limpieza, el consumo total de alimento aumentó 12,5% y las emisiones totales un 14%. La aplicación directa o luego del apilado o del compostaje del estiércol como fertilizante natural de N ahorra un 42 y 27% respectivamente las emisiones respecto de la aplicación de urea sintética

Modelación productiva, económica y emisión de metano en sistemas de cría vacuna de Bahía Blanca y Coronel Rosales

El objetivo de este estudio de simulación fue evaluar la respuesta productiva, económica, emisión de metano y el valor marginal del agregado de alimento extra (VMA) en diferentes sistemas la cría vacuna de Bahía Blanca y Coronel Rosales. Se utilizó información regional y un modelo de simulación dinámico bioeconómico y ambiental (SIMUGAN) para evaluar cuatro planteos ganaderos basados en la incorporación tecnológica de pasturas perennes y prácticas de manejo como el tipo de destete: Tradicional (Trad), Transicional 1 (Trans1), Transicional 2 (Trans2) y Tecnificado (Tecn). El aumento en productividad se asoció positivamente con el margen bruto [MB($/ha)=-1488,6+30,2 x producción de carne kg/ha/año, R2 0,99] y con menor intensidad de emisión de metano [IMC(kgCH4 CO2 -e/kg peso vivo producido)=20,4-0,1x producción de carne, R2 0,98]. El VMA ($/KgMS/ha), en calidad de indicador sistémico de oportunidades de suplementación estratégica, fueron mayores en los planteos Trad y Trans1 que en Trans2 y Tecn. En líneas generales, los distintos planteos simulados presentaron un mayor VMA durante las estaciones de invierno y primavera por sobre la distribución anual de alimento extra. El presente análisis integral permitió identificar y cuantificar oportunidades de mejora en la productividad de estos sistemas incorporando pasturas permanentes.The aim of this study was to evaluate the productive, economic, methane emissions performance and the marginal value of additional feed (MVF) for the different cow-calf systems from Bahía Blanca and Coronel Rosales. A dynamic “whole-farm” model (SIMUGAN) and regional data was used to evaluate four cow-calf system scenarios based on changes in pasture area and management policies as the weaning date: Traditional (Trad), Transitional 1 (Trans1), Transitional 2 (Trans2) and High Technology (HTech). The increase in productivity was positively associated with gross margin GM($/ha)=-1488.6+30.2 x beef production, R2 0.99] and negatively associated with methane emission intensity [IMC(kgCH4 CO2 -e/kg live weight produced)= 20.4-0.1 x production, R2 0.98]. The MVF ($/KgMS/ha) is a systemic indicator for strategic supplementation opportunities, and Trad and Trans1 achieved higher values than Trans2 and Tecn. Overall, the scenarios showed higher VMA when during winter and spring seasons, followed by the annual feeding. This global assessment showed positive opportunities for improving system productivity based on perennial pasturesEEA BordenaveFil: Fernandez Rosso, Catalina. Universidad Nacional del Centro de la provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Centro de Investigación Veterinaria de Tandil. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión de Investigaciones Científicas de la provincia de Buenos Aires; Argentina.Universidad Nacional del Centro de la provincia de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Lauric, Miriam Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bordenave. Agencia de Extensión Rural Bahía Blanca; ArgentinaFil: De Leo, Geronimo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bordenave. Agencia de Extensión Rural Bahía Blanca; ArgentinaFil: Bilotto, Franco. Universidad Nacional del Centro de la provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Centro de Investigación Veterinaria de Tandil. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión de Investigaciones Científicas de la provincia de Buenos Aires; Argentina.Universidad Nacional del Centro de la provincia de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Torres Carbonell, Carlos Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bordenave. Agencia de Extensión Rural Bahía Blanca; ArgentinaFil: Machado, Claudio F. Universidad Nacional del Centro de la provincia de Buenos Aires. Facultad de Ciencias Veterinarias; Argentina. Red Interinstitucional de Modelación Agropecuaria Buenos Aires Sur; Argentin

Effect of integrated manure management in a feedlot system : modelling of animal production and yield of greenhouse gases

Fil: Kazlauskas Kong, Leyli Giselle. Beca EVC-CIN.Fil: Bilotto, Franco. Universidad de Tandil. Facultad de Ciencias Veterinarias. Centro de Investigación Veterinaria de Tandil (CIVETAN). Tandil, Buenos Aires, Argentina.Fil: Fernandez Rosso, Catalina. Universidad de Tandil. Facultad de Ciencias Veterinarias. Centro de Investigación Veterinaria de Tandil (CIVETAN). Tandil, Buenos Aires, Argentina.Fil: Ferrati, Rosana. Instituto Multidisciplinario sobre Ecosistemas y Desarrollo Sustentable (UNCPBA- CIC). Buenos Aires, Argentina.Fil: Machado, Claudio F. Universidad de Tandil. Facultad de Ciencias Veterinarias. Centro de Investigación Veterinaria de Tandil (CIVETAN). Tandil, Buenos Aires, Argentina.El stock de ganado bovino en la Argentina es de 54,5 millones de cabezas, con una participación creciente de los sistemas “feedlot”. El objetivo de este trabajo es cuantificar las emisiones de gases de efecto invernadero de un sistema “feedlot” mediante el desarrollo de un modelo dinámico productivo que permite analizar el efecto del barro sobre el consumo y la ganancia de peso vivo (GPV) en diferentes condiciones climáticas, las posibles instancias de mitigación a partir del manejo del estiércol, incluyendo su aplicación como fertilizante natural, y la incidencia de las emisiones provenientes de la producción del alimento en el cálculo de emisiones totales.\nSe consideró un “feedlot” base de 2500 animales con dos ciclos consecutivos. La intensidad de emisión del “feedlot” fue de 3,6 kg CO2.Eq. kg-1 producido, proveniente por el 42,7% del alimento, 30,3% de la fermentación entérica, 22,5% del estiércol y 4.5% del mantenimiento del mismo. El efecto barro en condiciones de humedad media y alta aumentó en 0,8 y 5,4% las emisiones de GEI respecto de la condición moderada cuando se realizó limpieza del corral luego de finalizado el ciclo. En condiciones de humedad media y considerando dos ciclos sin limpieza, el consumo total de alimento aumentó 12,5% y las emisiones totales un 14%. La aplicación directa o luego del apilado o del compostaje del estiércol como fertilizante natural de N ahorra un 42 y 27% respectivamente las emisiones respecto de la aplicación de urea sintética.tbls., grafs

Effects of pre-operative isolation on postoperative pulmonary complications after elective surgery: an international prospective cohort study an international prospective cohort study

We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05–1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4–7 days or ≥ 8 days of 1.25 (1.04–1.48), p = 0.015 and 1.31 (1.11–1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care. We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05–1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4–7 days or ≥ 8 days of 1.25 (1.04–1.48), p = 0.015 and 1.31 (1.11–1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care

Global attitudes in the management of acute appendicitis during COVID-19 pandemic: ACIE Appy Study

Background: Surgical strategies are being adapted to face the COVID-19 pandemic. Recommendations on the management of acute appendicitis have been based on expert opinion, but very little evidence is available. This study addressed that dearth with a snapshot of worldwide approaches to appendicitis. Methods: The Association of Italian Surgeons in Europe designed an online survey to assess the current attitude of surgeons globally regarding the management of patients with acute appendicitis during the pandemic. Questions were divided into baseline information, hospital organization and screening, personal protective equipment, management and surgical approach, and patient presentation before versus during the pandemic. Results: Of 744 answers, 709 (from 66 countries) were complete and were included in the analysis. Most hospitals were treating both patients with and those without COVID. There was variation in screening indications and modality used, with chest X-ray plus molecular testing (PCR) being the commonest (19\ub78 per cent). Conservative management of complicated and uncomplicated appendicitis was used by 6\ub76 and 2\ub74 per cent respectively before, but 23\ub77 and 5\ub73 per cent, during the pandemic (both P < 0\ub7001). One-third changed their approach from laparoscopic to open surgery owing to the popular (but evidence-lacking) advice from expert groups during the initial phase of the pandemic. No agreement on how to filter surgical smoke plume during laparoscopy was identified. There was an overall reduction in the number of patients admitted with appendicitis and one-third felt that patients who did present had more severe appendicitis than they usually observe. Conclusion: Conservative management of mild appendicitis has been possible during the pandemic. The fact that some surgeons switched to open appendicectomy may reflect the poor guidelines that emanated in the early phase of SARS-CoV-2