Why is it recommended to vaccinate gilts at 6.5 months or older?

Vaccinating gilts at 6.5 months or older is commonly recommended primarily to prevent Erysipelas infections. Erysipelas is caused by the bacterium Erysipelothrix rhusiopathiae and can lead to significant health issues such as endocarditis, skin lesions, and reproductive failures in swine.

By vaccinating gilts before they reach the breeding stage or before they are introduced into a breeding herd, the immunity formed helps protect them and the future offspring against this disease. This timing is crucial as it provides adequate protection during their critical developmental stages and before they face potential exposure to pathogens in a breeding environment. Protecting against such infections ensures the overall health and productivity of the breeding stock.

While improving reproductive performance might be a consequence of vaccination, the primary objective is to ensure that gilts are shielded from disease, which can have direct implications on reproductive success. Therefore, preventing Erysipelas infections is the most pivotal reason for choosing to vaccinate gilts at this specific age.