Effect of temporary cessation of milking on the innate immune components in goat milk

摘要

Temporary cessation of milking is widely used duringthe dry period of dairy cows. Temporary cessation ofmilking induces an increase in the somatic cell count(SCC) and level of several inflammatory componentsof milk, which is believed to be a local adaptation anddefense mechanism of the mammary gland. In Japan,temporary cessation of milking combined with antibioticadministration is widely used to treat mastitis.The present study aimed to elucidate the role of theinnate immune system during temporary cessation ofmilking in a goat model by investigating the concentrationof several innate immune components in milkduring and around the temporary cessation. In experiment1, 6 goats were subjected to cessation of milkingfor 3 d in both udder halves, whereas in experiment2, 6 other goats were subjected to cessation of milkingfor 3 d only in 1 udder half. In experiment 1, themilk yield was lower on d 5 and 6, whereas the meanSCC was higher on d 5 compared with d 0 before temporarymilking cessation. The concentrations of goatDEFB1, S100A7, cathelicidin-2 and 7 (CATHL-2 and7), IgA, and lactoferrin were increased after temporarycessation of milking. In experiment 2, the milk yieldwas lower between d 5 and 7, whereas the mean SCCwas higher between d 4 and 7 compared with d 0. Theconcentrations of CATHL-2, IgA, and lactoferrin wereincreased after temporary cessation of milking only inthe udder half subjected to milking cessation. Theseresults suggest that temporary cessation of milkingincrease the SCC and concentration of several innateimmune components in milk without infection, whichmay contribute to mastitis treatment.