Goat colostrum IgG determination: Alternative methods to apply on farm

Abstract

Due to the type of placenta present in goats does not allows the transfer of antibodies from the mother to the fetus during gestation. For that reason, to ensure a correct passive immune transfer, colostrum intake plays a crucial role in the survival and development of the progeny in this species. Colostrum quality has been studied in deep, and it is well known that there are differences in colostrum composition, including IgG concentration, not only between species, but also within herds. Thus, to prevent the presence of failure of immune passive transfer in goat kids, the IgG concentration of colostrum needs to be checked. ELISA is considered nowadays as standards. However, it has some limitations such as the large time needed as well as the cost among others. So, the development and evaluation of additional techniques looking for the suitability of the results but also the possibilities to be applied on farms. The objectives of this study are to compare the analytical techniques used to determine IgG concentration in goat colostrum, as well as the use of a new method and its application on-farm. To do that, 40 colostrum samples from Majorera goats were analyzed using different techniques (ELISA, Clinic refractometer, Brix refractometer, Instrumental colour and an Alternative method). Descriptive statistics was performed and Saphyro-wik was used to analyze the normality. Pearson and Spearman´s correlation test were used for those variables with normal and non-normal distribution, respectively. Significant differences were set as p≤0.05. No high correlations (>0.6) between the studied techniques with the standard (ELISA) were observed. However, Brix and clinic refractometers were highly correlated (0.91; p<0.001). The Alternative Method tested in this study did not show strong correlation neither with ELISA nor with the any of the refractometers used, although it seems that 550 nm could be the better of the used wavelength. Further studies using more colostrum samples and testing a wider range of wavelengths are needed