Οι επιδράσεις της παστερίωσης στην μικροβιολογική ποιότητα και τις ανοσοσφαιρινές Α, Γ κατά την μετάβαση του γαιδουρινού πρωτογάλατος σε γάλα

Abstract

Aim of this study was to investigate the changes that occur in the mammary secretions of jennies during the first 18 days after foaling. The colostrum and milk of the jennies were analysed for active acidity (pH), the microbial quality and immunoglobulins A and G by the ELISA method. Measurements were also taken after pasteurisation of all samples at 63°C for 30 minutes and 72°C for 15 seconds. Samples were collected from two female donkeys of Cypriot breed 1, 3, 5, 6, 7, 8, 9 and 18 days after foaling. These two jennies were healthy and no problems occurred during their foaling. At first, the two pasteurisations of colostrum resulted in its coagulation, mainly due to the high levels of immunoglobulins. The pH of the raw samples showed an increasing trend over time. The colostrum had the lowest pH at about 6,47 ± 0,05 and the milk of 18th day reached 7,14 ± 0,03. Also according to the microbial analysis, the samples from 1st and 3rd day showed the lowest number of total viable counts. In all samples the predominant category of microorganisms was lactic acid bacteria. In addition, the immunoglobulins A and G, were at their highest concentration in colostrum, reaching 6,79 ± 0,14 mg/ml and 77,55 ± 6,12 mg/ml respectively. In the following days there was a reduction but in the 7th day there was a small increase in both immunoglobulins. Finally no significant differences in both immunoglobulins were observed between pasteurised and raw samples.