Oral administration of lipopolysaccharides from Escherichia coli (serotype O111:B4) does not induce an effective systemic immune response in milk-fed Holstein calves

摘要

It is well established that intravenous administrationof lipopolysaccharides (LPS)—cell wall componentsfrom gram-negative bacteria—induce acute inflammatoryresponses in dairy calves, but the effect of oraladministration of LPS to dairy calves is currently unknown.To evaluate the effects of oral administration ofLPS derived from Escherichia coli (serotype O111:B4)on innate immune responses in milk-fed Holstein calves,20 visually healthy calves (34 ± 1 d) received 4 L ofmilk with LPS (12 μg/kg body weight; n = 10; LPS)or without LPS (n = 10; control) at the morning feeding.Samples were collected at 0.5 h before the morningfeeding and at 3, 6, 24, 48, 72, and 168 h after themorning feeding to measure rectal temperature andheart rate, as well as plasma-negative and plasmapositiveacute phase proteins (i.e., haptoglobin, serumamyloid A, albumin, total protein, and fibrinogen) andimmunoglobulin concentrations (IgG, IgM, and IgA).None of these measurements was affected by the oraladministration of LPS. Oral administration of LPSat 12 μg/kg of body weight did not induce an acuteinflammatory response in visually healthy milk-fed Holsteincalves when administered in milk.