High-quality colostrum is crucial in preventing hypogammaglobulinemia and infectious diseases in foals. This study aims to estimate the suitability of a Brix refractometer for estimating IgG concentration. To estimate the reliability of using the refraction method (Brix refractometer) to assess colostrum quality in Dezhou donkeys by comparing its performance with that of the radial immunodiffusion method. Colostrum samples (n = 69) were collected from 23 Dezhou jennies at 0, 6, and 12 hours after birth. Regression analysis and one-way analysis of variance (ANOVA) were carried out on the collected data. The results showed strong correlations between the two methods (P<0.01). Regression analysis revealed a statistically significant relationship between the IgG concentration and Brix value (R²=0.9177). By using the regression equation between the two methods, the colostrum of Dezhou donkeys could be classified into four categories: excellent, good, fair, and poor quality, based on Brix values greater than 17.96, between 15.03 and 17.96, between 12.88 and 15.03, and less than 12.88%, respectively.  These results suggested that the refraction method can be a reliable and efficient alternative to estimate colostrum quality in Dezhou donkeys.

To Cite This Article: Li C, Gao N, Ding Z, Li H, Li M, Wei C, Wang H, Yu J, Wang T, Gong Y, Hou C, Zhuo K, Chen Y, Wang M, Zhu W, Zhang W, Khan A, Tang Y and Dong J, 2025. Rapid and accurate assay to detect IgG concentration in colostrum of Dezhou donkeys. Pak Vet J, 45(1): 445-449. http://dx.doi.org/10.29261/pakvetj/2025.134