形態・生理1

[IV-16-18] Changes in antibacterial component concentration in goat milk after cessation of milking

*孫 錦昆¹、鈴木 直樹¹、津上 優作¹、新居 隆浩¹、磯部 直樹¹ (1. 広島大院統合生命)

[Objectives] Mastitis frequently occurs during the dry period in dairy cows. We investigated changes in antimicrobial component concentration in goat milk after cessation of milking. [Methods] Tokara or Shiba goats at late lactation stage were used. Based on somatic cell count (SCC) before cessation, the udders were classified as high and low SCC (> or < 10⁶ cells/mL) groups, respectively, and the udders with high SCC induced by the lipopolysaccharide (LPS) infusion as LPS group. Milk was collected weekly for 8 weeks. [Results] Milk in the low SCC group was yellow and higher viscosity compared with the other two groups. SCC increased rapidly in only low SCC group after milking cessation and returned to a low value after 8 weeks. Lactoferrin, cathelicidin-2, cathelicidin-7 and S100A8 concentrations were higher in the low SCC group than other 2 groups after milking cessation. S100A7 showed the highest concentration in the LPS group. These results suggest differential antimicrobial components due to the inflammation status at the onset of milking cessation, which may be related to the prevention of infection in the mammary gland during the dry period.