###### Abstract  
Since the first proposal to use spray-dried porcine plasma (SDPP) as an animal-based protein source feed additive for piglets in the late 1980s, a large number of studies have been published on the promotion effect of SDPP on piglets. SDPP contains biologically active components that support pig health during weaning stress and may be more economical to use compared to similar bovine-milk-derived protein sources. Unfortunately, animal blood proteins have been suspected as a source for African Swine Fever Virus (ASFV) spread in China. Furthermore, there are no officially recognized methods for quantifying SDPP in complex feed mixtures. Therefore, it is essential to develop rapid, high-effciency analytical methods to detect SDPP. The feasibility of detecting SDPP using an electronic nose and near-infrared spectroscopy (NIRS) was explored and validated by a principal component analysis (PCA). Both discrimination experiments and prediction experiments were implemented to compare the detect feature of the two techniques. On this basis, partial least squares discriminant analysis (PLS-DA) under various preprocessing methods was used to develop a qualitative discriminant model for estimating the prediction performance. Before selecting a specific regression model for the quantitative analysis of SDPP, a continuum regression (CR) model was employed to explore and choose the potential most appropriate regression model for these two different types of datasets. The results showed that the optimal regression model adopted partial least squares regression (PLSR) with the Savitzky-Golay first derivative and mean-center preprocessing for the NIRS dataset (R\({}_{\text{P}}^{2}\) = 0.999, RMSEP = 0.1905). Overall, combining the NIRS technique with multivariate data analysis methods shows more possibilities than an electronic nose for rapidly detecting the usage of SDPP in mixed feed samples, which could provide an effective way to identify the use of SDPP in feed mixtures. continuum regression; discriminant analysis; electronic nose; Fourier transform near-infrared spectroscopy; regression analysis; spray-dried porcine plasma +
Footnote †: journal: Applied(ASFV) can be spread by contamination of livestock feed. The risks for ASFV transmission in feed were evaluated by [PERSON] et al. Their findings demonstrated that the ASFV Georgia 2007 strain can easily be transmitted orally when consumed in liquid, but requires a much higher dose when provided in feed [1]. Recently, [PERSON] et al. detected the first ASFV, named Pig/HLJ/18, in Heilongjiang, and this virus is highly virulent and transmissible in domestic pigs in China [2]. [PERSON] et al. adopted gene sequencing analysis and indicated that the ASFVs derived from a pig sample and the SDPP of pig feed, in Jiamusi, Heilongjiang, were identical--both were Pig/HLJ/18 ASFV--which was the same strain found in previous studies. These findings demonstrated that using SDPP as a creep feed supplement could result in a substantial potential hazard for the spread of ASF [3]. To respond to the extremely grim situation in China, Regulation 64/2018, which was issued by the Ministry of Agriculture and Rural Affairs, mandated that the use of SDPP in creep feed be suspended to prevent and control the spread of ASF. Although SDPP plays a crucial role in creep feed, as it can promote intestinal development in piglets and prevent diarrhea [4], it was important to discriminate SDPP from other feed additives. Whey protein concentrate (WPC) is the best substitute for SDPP, but WPC is much more expensive, with a cost of nearly twice that of SDPP. Furthermore, studies have shown that WPC is only half as efficient as SDPP [5]. Later, the new Regulation 91/2018 was issued and implemented, under which ASFV-genome-free porcine blood products are permitted for use again in feed for swine. Hence, the quantitative analysis of the SDPP concentration detection also becomes meaningful. Thus, inspecting the usage of SDPP is an effective measure for verifying declared ingredients used in commercial feed.