Increased blood levels of haptoglobin (Hp) [8, 23], tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) [24] have been found in sows diagnosed with MMA, and a decrease in white blood cell counts (WBC) and neutropenia was observed in sows developing agalactia after experimental intramammary infusion of Escherichia (E.)coli [25]. Here, TNF is linked to neutropenia.