Evaluation of Lactoferrin Concentrations in Goat Milk from Udder Inoculated with Staphylococcus aureus

Abstract

The purpose of this study is to monitor the variation of milk lactoferrin concentrations (LFC) during subclinical mastitis in dairy goats after an intramammary bacterial inoculation. Two Alpine and two Saanen lactating goats in mid-lactation of first lactation were used in this study. One of the healthy udder halves of each goat was inoculated with Staphylococcus aureus. Daily changes of lactoferrin concentration (LFC) in normal and subclinical mastitis milk were determined for two weeks. For comparison, all milk samples were also monitored for their somatic cell count (SCC). standard plate count (SPC). California mastitis test (CMT), and milk yields. Daily LFC of the infected milk increased from below 30μg/mL(day 1) to 1000μg/mL (day 4) and gradually decreased to 100 to 300 μg/mL (day 10). It remained at this level till the end of the experiment (day 14). In contrast, daily LFC in non-mastitis control milk were consistent at about 30 to 100 μg/mL for the 14 day-duration of the experiment. The LFC was significantly higher in the infected milk than that in normal milk after day 3. The SCC and CMT scores were also significantly higher in the infected milk as compared to that in the normal milk after day 3. In conclusion, inoculation of S. aureus into udder halves of goat resulted in a 10 to 100 folds increase of milk LFC, but the LFC in milk from healthy goats were constantly found to be at low and steady levels.