Arterial blood analysis of healthy residents in Huamachuco, Peru (3,164 m): a cross-sectional study.

Background: Given that arterial blood gas is affected by altitude and ethnicity, establishing reliable reference standards for these values requires analysis of arterial blood at different elevations and locations. Our objective was to measure the arterial blood gases of healthy young volunteers in Huamachuco, Peru, at 3,164 m above sea level. This is likely the first study of arterial blood gas analysis of healthy Northern Peruvians living at high altitude. Methods: Healthy residents of Huamachuco were recruited for this cross-sectional convenience sample study and arterial blood was drawn by standard procedures. People with obesity, diabetes, high levels of physical activity and a history of using selected substances were excluded. The samples were analyzed on-site in less than 15 minutes using a Stat Profile Prime CCS analyzer (Nova Biomedical). Results: Data from 46 participants (17 male, 29 female) were included in the study. The median values for arterial blood pH, oxygen, carbon dioxide, ionized calcium, glucose, lactate, hematocrit, oxygen saturation, and bicarbonate were 7.42, 9.3 kPa (70 mmHg), 4.5 kPa (33.5 mmHg), 1.04 mM, 5.19 mM, 1.8 mM, 50 %, 94 %, and 21.6 mM, respectively. We also found a lower prevalence of diabetes among highlanders compared to the Peruvian population. Conclusions: The results determined here were comparable to other results determined at different altitudes in the Americas, although arterial blood oxygen was slightly higher than predicted. These results indicate that Northern Peruvians have an Andean-style adaptation to high altitude.

Organic acids for broilers: Effects on intestinal morphology and growth performance / Ácidos orgánicos para pollos de engorde: Efectos sobre la morfología intestinal y el rendimiento del crecimiento / Ácidos orgânicos para frangos de corte: Efeitos na morfologia intestinal e no desempenho de crescimento

Abstract Background: Organic acids and ammonium salts added to drinking water can optimize productivity of broiler chickens. Objective: To evaluate the effect of acidifying drinking water on productive performance, blood and intestinal pH, and intestinal morphology of broilers. Methods: 1,400 one-day-old broiler chicks were used to evaluate two pH levels (4 and 6) of drinking water during three periods (1-21, 1-28, and 1-42 days of age). The treatments consisted of water added with a blend of formic acid (31%), propionic acid (19%), and their salts ammonium formate (26%), and ammonium propionate (6%) compared to a control group (pH 8). Results: Compared to the control, the groups consuming water at pH 6 (0.038 moles) continuously for 42 days improved (p≤0.01) live weight (2.785 vs 2.691 kg), feed conversion ratio (1.430 vs 1.463 kg/kg), and increased the number of intestinal villi (59.0 vs 55.7). Additionally, blood and intestinal pH was reduced vs the control group (7.75 vs 7.89; 6.32 vs 6.41, respectively). Conclusion: The blend of formic and propionic acids and their ammonium salts in drinking water at pH 6 during the complete production cycle of broilers improves performance, increases the number of intestinal villi, and reduces the pH of blood, duodenum, and ileum.

Resumen Antecedentes: Agregar ácidos orgánicos y sus sales amoniacales en el agua de bebida de pollos de engorde puede optimizar su productividad. Objetivo: Evaluar el efecto de la acidificación del agua de bebida sobre el rendimiento productivo, pH sanguíneo e intestinal, y morfología intestinal del pollo de engorde. Métodos: Se utilizaron 1.400 pollos de engorde de un día de edad para evaluar dos niveles de pH (4 y 6) en agua de bebida durante tres períodos (1-21, 1-28 y 1-42 días de edad). Los tratamientos consistieron en agua con una mezcla de ácido fórmico (31%), ácido propiónico (19%) y sus sales formiato de amonio (26%) y propionato de amonio (6%) en comparación con un grupo control (pH 8). Resultados: En comparación con el control, los grupos que recibieron agua a pH 6 (0,038 moles) continuamente durante 42 días tuvieron mejor (p≤0,01) rendimiento en términos de peso vivo (2,785 vs 2,691 kg) y conversión alimenticia (1,430 vs 1,463 kg/kg) así como un mayor número de vellosidades intestinales (59,0 vs 55,7). Adicionalmente, el pH sanguíneo e intestinal disminuyó vs el grupo control (7,75 vs 7,89; 6,32 vs 6,41, respectivamente). Conclusión: La mezcla de ácidos fórmico y propiónico y sus sales de amonio en el agua de bebida a pH 6 durante todo el ciclo productivo mejora los parámetros productivos en pollos de engorde, aumenta el número de vellosidades intestinales y reduce el pH de la sangre, duodeno e íleon.

Resumo Antecedentes: Recomendações para a aplicação de mistura de ácidos orgânicos e sais de amônio na água potável são necessárias para otimizar a produtividade em frangos de corte. Objetivo: Avaliar o efeito da acidificação da água de bebida no desempenho produtivo, pH sanguíneo e intestinal e morfologia intestinal. Métodos: 1.400 pintos de corte entre 1 e 42 dias de idade foram utilizados para avaliar dois níveis de pH (4 e 6) na água de beber entre três períodos (1-21, 1-28 e 1-42 dias de idade) de tratamentos em água com uma mistura de ácido fórmico 31%, ácido propiônico 19%, e seus sais formato de amônio 26% e propionato de amônio 6% em relação ao controle (pH 8). Resultados: Os grupos que receberam água continuamente pH 6 (0,038 mols), por 42 dias tiveram melhor desempenho em relação ao controle (p≤0,01) em termos de peso vivo (2,785 vs 2,691 kg) e conversão alimentar (1,430 vs 1,463 kg/kg), bem como aumento do número de vilosidades intestinais (59,0 vs 55,7), sangue e pH intestinal reduzidos vs controle (7,75 vs 7,89; 6,32 vs 6,41). Conclusão: A mistura dos ácidos fórmico e propiônico e seus sais de amônio na água de bebida em pH 6 durante o ciclo completo de produção melhorou os parâmetros de produção em frangos de 42 dias de idade e aumentou o número de vilosidades intestinais e uma redução no sangue, duodeno, e pH do íleo.

Capture stress and post-release mortality of blacktip sharks in recreational charter fisheries of the Gulf of Mexico.

Understanding the stress responses of sharks to recreational catch and release fishing has important management and conservation implications. The blacktip shark Carcharhinus limbatus is a popular recreational species targeted throughout the western, central and eastern Gulf of Mexico (Gulf) yet it is unclear what levels of physiological stress result from catch-release fishing practices with hook and line gear and if the stress levels result in post-release mortality. This study correlates physiological response to stress through blood chemistry analysis and examines post-release behaviour of adult blacktip sharks caught to determine post-release mortality rates. Release behaviour was determined by pop-up satellite archival transmitting (PSAT) tags that record temperature, depth and light level data. To quantify physiological stress levels, blood samples were collected from 52 blacktip sharks and a suite of metabolic and osmotic markers were measured. Thirty-six of those blacktip sharks were also outfitted with a PSAT tag yielding time-at-large from 3 to 180 days. Of the 36 tags, 22 (61%) provided sufficient data to confirm post-release fate and 11 (31%) were recovered providing high-resolution data. Tag data suggests a post-release morality rate of 22.7% (95% confidence interval 7.8-45.4%), with mortality occurring within minutes (immediate mortality) to over 12 h post-release (delayed mortality). Compared to survivors, immediate mortalities exhibited significantly higher lactate (median 2.8 mmol/Lsurvivor vs 5.9 mmol/Limmediate mortality) and significantly lower hematocrit (median 24.4% survivor vs 14% immediate mortality) levels, but no difference was detected between survivors and delayed mortalities. Higher mortality in the western (30%) compared to the central (20%) Gulf may be due to shark handling. All PSATs from mortalities (N = 5) were recovered, and archived data revealed evidence of tag ingestion by predators. Results suggest reduced fight time, decreased handling time and limited air exposure provide blacktip sharks the best survival chances after release by recreational anglers.