The fresh cow experiences several metabolic disorders that often occur at a subclinical level, the most common of these being ketosis and acidosis. Both of these metabolic disorders cause immunosuppression. This, along with the negative energy balancedue to increase in milk production and lower feed intake, makes the postpartum cow a poor target for a strong immune response. Timing of booster vaccinations should take these metabolic factors into consideration resulting in vaccination later in the postpartum period or earlier in the dry cow period.
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