Francis M J, Black L
Res Vet Sci. 1984 Jul;37(1):72-6.
Three pairs of sows were vaccinated against foot-and-mouth disease (FMD) at various intervals before farrowing and samples of blood were collected from their piglets periodically for 70 days after birth. When the sows were vaccinated 12 to 13 days before farrowing the predominating FMD neutralising antibody at time of parturition was IgM and the observed half lives of the maternally derived antibodies in the piglets were short (four to eight days). However, when sows were last vaccinated 30 to 32 days before farrowing, the maternally derived FMD neutralising antibodies in the piglets were predominantly IgG and the observed half lives were seven to 21 days. These observed half lives for IgG were shown to be closely related to the period over which the maternally derived antibodies could be demonstrated and to the rate of increase of the piglet's blood volume over the same period. If corrections were made for increase in blood volume the decay rate of IgM antibodies in piglets was seven to 18 days while the decay rate for IgG was greater than 408 days. This result suggested that there was little or no IgG catabolism or excretion during the first 70 days of the piglet's life.
三对母猪在分娩前不同时间间隔接种口蹄疫（FMD）疫苗，并在其仔猪出生后70天内定期采集血样。当母猪在分娩前12至13天接种疫苗时，分娩时占主导的口蹄疫中和抗体是IgM，且仔猪中母源抗体的观察到的半衰期较短（4至8天）。然而，当母猪在分娩前30至32天最后一次接种疫苗时，仔猪中母源的口蹄疫中和抗体主要是IgG，观察到的半衰期为7至21天。这些观察到的IgG半衰期显示与母源抗体能够被检测到的时间段以及同一时期仔猪血容量的增加速率密切相关。如果对血容量增加进行校正，仔猪中IgM抗体的衰减速率为7至18天，而IgG的衰减速率大于408天。这一结果表明，在仔猪生命的前70天内，几乎没有或不存在IgG的分解代谢或排泄。
