Weaning pigs at an early age decreases cellular immunity

Area of Science:

• Animal Science
• Immunology
• Veterinary Medicine

Background:

• Early weaning is a common practice in pig farming.
• The impact of weaning age on young pigs' immune system requires further investigation.

Purpose of the Study:

• To evaluate how different weaning ages affect cell-mediated immunity in pigs.
• To determine the effects of early weaning on both in vivo and in vitro immune responses.

Main Methods:

• 118 pigs were divided into groups weaned at 2, 3, 4, or 5 weeks of age, with controls remaining with the sow.
• Phytohemagglutinin skin tests assessed in vivo cellular immunity.
• Lymphocyte blastogenic responses to mitogens were measured before and after weaning.

Main Results:

• Weaning at 2 or 3 weeks significantly reduced phytohemagglutinin skin-test responses.
• Lymphocyte blastogenesis was decreased in pigs weaned at 2 and 3 weeks.
• Pigs weaned at 5 weeks showed no significant alteration in cellular immunity compared to controls.

Conclusions:

• Weaning pigs before 5 weeks of age detrimentally affects their cellular immune reactivity.
• Early weaning may compromise the immune system of young pigs, potentially increasing their susceptibility to diseases.