Disruption of Tight Junction Integrity, and Induced Mammary Involution in Lactating Goats by Saponins

Four multiparous pregnant Nubian goats at late lactation were subjected to injection of a saponin preparation from Gypsophila roots. Saponin solution was injected into one single gland of each goat after milking 8 times. At day 2 in treatment, milk yield began to be affected, and dropped down dramatically from day 3 till dry off at day 8. The pH value of milk was increased in udder halves treated with the saponin solution after 2 days, whereas the control halves exhibited semi-plateau manner all over the experiment. Sodium concentration increased and potassium concentration decreased after 2 d in treatment. Calcium concentration in the treated udder declined after 8 d and the values of these ions were roundabout the plasma concentrations indicating that milk secreted from the treated udder halves with saponins was mostly composed of interstitial fluid.