Quality determination of fresh, refrigerated, frozen an refrozen goat colostrum using an optical and BRIX refractometer

Abstract

Colostrum is the first source of immunoglobulins, especially IgG, in newborn goat kids, therefore it is of vital importance that they consume it during the first hours of life. However, in many cases reduced colostrum volumen or low-quality colostrum (i.e., low IgG concentration) force farmers to have good-quality colostrum stored. As there is a strong correlation between IgG concentration and BRIX degrees, optical and digital refractometers has been used in fresh colostrum to quickly determine colostrum quality (i.e., IgG concentration). Considering this need, the present study animed to investigate if the use of optical and digital refractometers could be used to quickly determine colostrum quality in fresh, refrigerate, frozen and refrozen colostrum. The results of the sent study showed that IgG concentration was not affected by treatment (P = 0.995). However, BRIX degrees measured with the digital refractometer tended to be affected by the treatment (P = 0.086). Regarding the correlation between IgG and BRIX degrees, there was a high correlation in fresh colostrum (r = 0.80), although no correlation was observed for those refrigerated, frozen or refrozen colostrums (r = 0.11, r = 0.33, r = 0.29, respectively). The results of the present study contribute to understand the chemical changes of colostrum stored at different changes and may set the path for future research on the field.