# Palatability Testing of Spray-Dried Animal Plasma-Infused Dog Foods and Treats
## 4 Discussion  
Understanding the intricacies of canine feeding behavior is crucial for devising optimal formulations that enhance palatability while addressing health and welfare considerations. Numerous factors influence a dog's food selection, including the nutritional composition of the food itself. Wet pet food is generally more appealing to pets than dry food due to its enhanced palatability [34], underscoring the pivotal importance of palatability considerations, particularly in the production of dry pet food. Quality control and product development tests for pet foods often involve palatability testing with dogs and cats, underscoring the significance of palatability in pet food formulation [20]. Dry pet foods are the most popular pet food category purchased by pet owners because of their long shelf life, ease of preparation, and low price; however, they tend to be low in terms of their palatability to dogs compared to the wet and semi-moist types [35].  
The incorporation of SDAP into dog and cat food formulas is not a novel concept. Due to the documented beneficial effects of this dietary supplement on the growth, immunity, and hematological parameters of livestock [36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46], its use was extended to pets several decades ago. However, the palatability outcomes have not yet been conclusively determined. While in the case of cats, the SDAP additive demonstrated an evident positive impact on food palatability [14; 47], in the case of dogs, the results were inconsistent.  
[PERSON] et al. [14] found that the palatability or first-choice results with dogs were similar in both trials (1. containing 20 g/kg of SDAP or wheat gluten; 2. containing 10 g/kg of SDAP or 30 g/kg of wheat gluten), indicating that dogs cannot differentiate between the two products. [PERSON] et al. [48] did not find any differences in food intake when dogs were fed diets containing up to 3% SDAP either. [PERSON] et al. [18] observed that while most dogs showed a preference for a diet without SDAP addition over a diet containing 4% SDAP when both options were presented simultaneously, there was no significant difference in food intake when each diet was offered separately in a digestibility trial. This suggests that dogs do not reject foods (even with up to 12% SDAP), although they may opt for diets without SDAP when given a choice. In contrast, in our study, dogs were more likely to choose products with 2% SDAP content compared to control diets (i.e., 0% SDAP), while they were less likely to choose those with higher SDAP content (4%) (Figure 1). Considering our results alongside those of previous studies, it can be concluded that dogs' preference for SDAP is closely linked to its concentration in the product. Even small differences in the amount of SDAP in the food formulation (1%, 2%, 3%, or 4%) can significantly affect the product's palatability. Based on the results of previous studies and our findings, the addition of SDAP to dog food should be kept at 2%. Higher amounts (even 4%) have been found to reduce the palatability of dog products. It is important to note that a strong initial choice is often correlated with a higher food intake [49; 50; 51]. Although food intake was not measured in our study, it is reasonable to assume that the dogs ate more of their first choice.  
This study represents the first investigation to specifically examine the impact of SDAP on the palatability of dog treats. While previous research has explored the effects of SDAP in dog food, our study uniquely analyzes its inclusion in treats, which are a significant aspect of canine diets used for training, rewarding, and supplemental nutrition. Our findings demonstrate that a 2% addition of SDAP to dog treats enhances their palatability compared to the control diet (0% SDAP) (Figure 1), making them more appealing to dogs. This enhanced palatability can be particularly beneficial for products aimed at training or therapeutic purposes, where high acceptance is crucial.