Curtis S E, Kingdon D A, Simon J, Drummond J G
Am J Vet Res. 1976 Mar;37(3):299-301.
Young pigs (1, 6, 18, or 26 days of age) were exposed to an aerosol of a nonpathogenic strain of Escherichia coli and then held for a 3-hour clearance period in either a thermoneutral (32 C environmental temperature at 1 or 6 days of age, 24 C at 18 or 26 days of age) or a cold (6 C) environment. Pigs were then killed and pulmonary bacterial clearance was determined. There appeared to be an age dependent improvement in the capability of the pig to clear its lungs of the bacterial load. Cold appeared to inhibit pulmonary bacterial clearance, but this inhibitory effect became progressively less as the pigs became older. In a supplementary experiment conducted to assess the effect of age-within-litter (2 and 14 days of age) on pulmonary bacterial clearance, it was confirmed that young pigs were less able to clear nonpathogenic E coli from the lungs.
将幼猪（1、6、18或26日龄）暴露于非致病性大肠杆菌菌株的气溶胶中，然后在热中性环境（1或6日龄时环境温度为32℃，18或26日龄时为24℃）或寒冷环境（6℃）中保持3小时的清除期。随后处死幼猪并测定肺部细菌清除率。幼猪清除肺部细菌负荷的能力似乎存在年龄依赖性改善。寒冷似乎会抑制肺部细菌清除，但随着幼猪年龄增长，这种抑制作用逐渐减弱。在一项补充实验中，为评估同窝幼猪年龄（2和14日龄）对肺部细菌清除的影响，证实幼猪清除肺部非致病性大肠杆菌的能力较弱。
