Access to open water is considered good for the health and welfare of Pekin ducks. These studies investigated: 1.- the effect of water resource type (nipple drinker, narrow bell drinker, wide bell drinker, trough or pool) on duck health and behavior; 2.- the preference shown by ducks between pools of different depths (10cm, 20cm or 30cm) and whether the behaviours performed differed between these depths. Stage 1.- There was a significant effect of treatment on hygiene scores and nostril condition, with baths and troughs being better than the other resources. Overall, there was no effect of treatment on eye health score, gait or foot pad dermatitis. Significantly fewer ducks were resting inactive by the baths and troughs, and the % of ducks performing bathing behaviours was higher in those resources. Stage 2.- None of the factors analyzed had a significant effect on pool preference. Provision of open water seems to improve some aspects of duck health and welfare, and ducks were neither more attracted to, nor more averse to, deeper water. However, further work is needed to investigate open water resources such as pools or troughs at a commercial scale.

Trabajo presentado al: XLVII Congreso Nacional y XXIII Internacional de la Sociedad Española de Ovinotecnia y Caprinotecnia (SEOC). Valencia (España). | Este estudio se enmarca en el proyecto PID2020-113395RB-C22 financiado por MCIN/AEI/10.13039/501100011033. | Peer reviewed

Salt baths in the production system of salmonids in fresh water, are important for the prevention and control of different diseases such as saprolegnia fungus. This standard procedure generates a rapid depletion of O2 in the water, leading to a significant increase of CO2, affecting blood parameters associated with animal welfare, such as Na+, Cl-, glucose and protracted hypercarbia. The aim of this study was to evaluate the response field of blood parameters related to fish welfare and the physical-chemical parameters of water to which they are subject during this period, comparing two sets of bath salt. One group of farmed Atlantic salmon (Salmo salar) in the pre-smolt stage was exposed in a salt bath system with the usual conditions and a second to a recirculation system with a waterfall for degasification, with two different exposure periods of one and two hours. The results of the concentration of CO2 in the water show significant variations between the two systems without recirculation compared to the control condition and salt. Significant differences were observed between the recirculating system and the control in blood levels of pCO2 and HCO3, but not pH. Our field data also show that salt baths that are performed regularly at the fish farms generate significant effects on blood parameters associated with animal welfare specifically fish pCO2 and HCO3 causing minor hypercarbia without generating blood acidosis. The addition of water recirculation with a waterfall does not affect blood parameters. | Los baños de sal, dentro del sistema productivo de salmónidos en agua dulce, son un paso clave en la prevención y el control de diferentes enfermedades como la saprolegnia. Este procedimiento habitual genera un agotamiento rápido del O2 en el agua, lo que genera un aumento significativo del CO2 en el agua, afectando parámetros sanguíneos asociados a bienestar animal, como Na+, Cl-, glucosa y en situaciones prolongadas hipercapnia. Este trabajo tiene como objetivo evaluar en terreno la respuesta de parámetros sanguíneos asociados a bienestar de los peces y parámetros físico-químicos del agua a la que están sometidos en este periodo, comparando dos sistemas de baño de sal. Para ello se sometió a un grupo de Salmo salar en etapa pre-smolt a un baño de sal habitual, otro grupo a un sistema de recirculación con cascada de agua para su desgasificación y un grupo control sin sal, exponiéndolos a diferentes periodos de una y dos horas. Los resultados de la concentración de CO2 en el agua muestran variaciones significativas entre ambos sistemas con y sin recirculación para la condición control y con sal. Los niveles sanguíneos evaluados en terreno de PCO2 y HCO3 presentaron diferencias significativas respecto del sistema con recirculación y al control, no así los niveles sanguíneos de pH. Nuestros datos de terreno demuestran que los baños de sal que se realizan con regularidad en los centros de cultivo generan efectos significativos sobre parámetros sanguíneos asociados a bienestar animal de los peces, específicamente PCO2 y HCO3, provocando hipercapnia leve sin generar acidosis sanguínea, al añadir recirculación del agua con una cascada a los baños de sal, no se ven afectados los parámetros sanguíneos.