Show vaccination tests at experiment stations vaccination tests at ames kansas and other experiment stations indicate that pigs even a few days old can be immunized against cholera in a high percentage of cases and with pigs approaching weaning seven to nine weeks w eel s old immunity is as certain as with old hogs the explanation offered by careful observers of tills this apparent variation between experiments and practice generally binges on this fact P pigs gs up to til or eight weeks of age have tender pliable skin and soft flesh with ordinary vai vaccinating practice tle where rapid handling and treatment is commonly the rule it is probable that among certain individual pigs there Is more or less leakage of serum from the hole bole through which it was injected it if this is true it does offer a reasonable ond and plausible explanation why vaccination Is uncertain with young pigs this fault or error should not apply to pigs eight weeks old or older especially when the job is carefully done with speed not the dominating thought while the job is being done it appears to be sound policy to vaccinate pigs when the younger ones reach two months of age |