Predictive equations of selenium accessibility of dry pet foods
Dry pet foods are the most popular commercial diet type selected for pet dogs (Pet Food Manufacturers' Association, 2015). Dry pet foods can be processed by either extruding to kibbles or pelleting. Pellets and kibbles are formulated with a large range of both plant‐ and animal‐derived ingredients. Depending on the region of origin and type of ingredient, the Se concentration in pet food ingredients can differ (Reilly, 2006; van Zelst et al., 2015). In addition, the bioavailability of Se from pet foods has been reported to be low (Wedekind et al., 1997) and dependent on various factors such as protein, fat, sulphur and fibre content of the diet (Thiry et al., 2012). Therefore, the total dietary Se concentration may not reflect the amount of Se that is available to the animal.
This study aimed to develop equations to predict the amount of dietary Se from dry pet foods that is potentially available for dogs, expressed as in vitro accessibility (Aiv). This formed an estimation for in vivo availability for further confirmation in vivo in dogs. Accessibility here is defined as the percentage of dietary Se that is potentially available for absorption after in vitro digestion.