The aim of this study was to investigate the biochemical indices in the saliva of leisure and sport horses undergoing different levels of workload. The experiment was conducted on 40 horses (4–28 years): sport horses (n = 20), and leisure horses (n = 20). The saliva samples were collected non-invasively 15 min before riding (A), 1 min before riding (B), 1 min after riding (C) and 15 min after riding (D). Albumin (Alb), alkaline phosphatase (ALP), α-amylase (AMY), creatine kinase (CK), creatinine (Crea), glucose (Glc), lactate (Lac), triacylglycerols (TG), total protein (TP), urea and lipid peroxidation (TBARS) were measured in saliva. Riding caused a significant change in many biochemical indices (Alb, CK, Glc, Lac, TBARS and urea) compared to baseline values in leisure horses ( P < 0.05) but only in a few indices (Glc, Crea and TBARS) in sport horses. On the other hand, when comparing groups of leisure and sport horses, higher concentrations of Alb, Glc, TG and urea were found in sport horses whereas raised concentrations of CK and Crea were found in leisure horses. The obtained results indicate the adaptation of trained horses to physical effort. Moreover, this study confirms other possibilities of using salivary biochemical properties for physical stress assessment. Other more detailed comparative studies of load response in horses may provide useful information to quantify the reference range of individual stress indices.

The aim of the study was to analytically evaluate quantum dots in immunohistofluorescence (IHF-QD) microscopic imaging as detectors of food allergens—peanut and wheat. The experiment was designed as two in silico experiments or simulations: (a) models of pastry samples were prepared with the addition of allergenic components (peanut and wheat protein components) and without the addition of allergenic components, and (b) positive and negative commercial samples underwent food allergen detection. The samples from both simulations were tested by the ELISA and IHF-QD microscopic methods. The primary antibodies (secondary antibodies to a rabbit Fc fragment with labeled CdSe/ZnS QD) were labelled at 525, 585, and 655 nm emissions. The use of quantum dots (QDs) has expanded to many science areas and they are also finding use in food allergen detection, as shown in the study. The study indicated that differences between the ELISA and IHF-QD microscopic methods were not observable among experimentally produced pastry samples with and without allergenic components, although differences were observed among commercial samples. The important value of the study is certainly the differences found in the application of different QD conjugates (525, 585, and 655). The highest contrast was found in the application of 585 QD conjugates that can serve for the possible quantification of present food allergens—peanuts and wheat. The study clearly emphasized that QD can be used for the qualitative detection of food allergens and can represent a reliable analytical method for food allergen detection in different food matrixes.