## 1 Introduction  
Finding alternatives to human milk is crucial when breastfeeding is impossible and cov milk is unobtainable. According to several authors, donkey milk is the best human milk substitute [1], mainly because its composition is clearly more similar to human milk than that of other animals (cow, buffalo, sheep, goat and camel [2]) and additionally due to its nutrient and functional compound richness [3]. Colostrum, the initial secretion of milk in mammals, is an important fluid that contains bioactive components, namely immunoglobulins (lgs: IgA, IgM and IgG) and substantial concentrations of antimicrobial factors, including elevated levels of various enzymes (e.g., lysozyme) possessing antimicrobial properties [4]. Even though colostrum is richer in dry matter, protein, fat, vitaminsBoth human colostrum and milk are currently processed by thermal pasteurization in low-temperature/long-time conditions (62.5 \({}^{\circ}\)C, 30 min) in human milk banks, a process known as Holder pasteurization [6; 7]. However, it has been verified that when TP is applied to human colostrum, a decrease in IgA, IgM and IgG is observed, for instance, in values around 20, 51 and 23%, respectively [7], thus reducing the nutritional and functional quality. In lieu of traditional thermal pasteurization (TP), high-pressure pasteurization (HPP) without the application of heat can serve as a nonthermal method for pasteurization. HPP has the capability to inactivate microorganisms, resulting in the production of safe and minimally processed food products. Additionally, HPP helps to preserve the nutritional and organoleptic qualities of the food to a greater extent [8]. No publications were found concerning HPP's effect on the microbiological quality and immunologic parameters (Igs and lysozyme activity) of donkey colostrum, although there are a few studies on donkey milk [9; 10] but dealing only with microbial quality. [PERSON] et al. (2016) [10] studied the effects of TP (65 \({}^{\circ}\)C, 30 min), HPP (400 MPa, 180 s) and TP+HPP (65 \({}^{\circ}\)C, 30 min + 400 MPa, 100 s) on microbiological indicators of donkey milk hygiene and their evolution during storage at 4 and 12 \({}^{\circ}\)C for 30 days, simulating a farm-scale pasteurization and packing system. In this study, it was verified that the HPP treatment of pasteurized milk extended the shelf-life of donkey milk and assured its microbial criteria for consumption up to 30 days if properly stored at 4 \({}^{\circ}\)C, verifying that combining both TP and HPP treatments allowed the enhancement of donkey milk shelf-life from 3 to 30 days. Recently, [PERSON] et al. (2023) [9] investigated the viability of _Escherichia coli_ O157:H7 in raw donkey milk, as well as in thermally pasteurized (50 \({}^{\circ}\)C for 30 min, TP) and HPP (400 MPa at 3 \({}^{\circ}\)C for 60 s) mills, and by combining TP+HPP. The authors reported that _E. coli_ O157:H7 exhibited viability in untreated donkey milk for a duration of 15 days, but in TP milk, it survived for a period of 4 days. The application of HPP effectively eliminated the pathogen, as it was not found from the beginning of the treatment. Hence, the application of HPP demonstrated efficacy in ensuring the microbiological integrity of the product. Regarding the effect of HPP on immunologic parameters (Igs and lysozyme activity), there are a few studies on colostrum from other species but none on donkey colostrum, for instance in caprine [11] and human [7; 12] colostrum. For caprine colorstrum, treatment at 400 and 500 MPa caused a decrease in the IgG content from 20 to 40%, respectively [11]. In human colostrum, low pressure levels (200-400 MPa) did not affect Ig content, but contrarily, 600 MPa (2.5 min) promoted IgM and IgG losses (21%) despite the maintenance of IgA. Longer treatments (600 MPa, 15 and 30 min) caused similar or higher Igs losses comparatively to TP [7], while lysozyme seemed to be resistant in HPP-treated human colostrum (statistically similar to unprocessed human colostrum) when compared to TP, which decreased 44%.