Growth and microbial flora of nonmedicated, segregated, early weaned pigs from a commercial swine operation.

OBJECTIVE: To determine whether segregated, early weaned pigs have better growth performance and different microbial flora than those pigs raised on-site. DESIGN: Prospective, observational study. ANIMALS: Pigs from a commercial operation that were known to be infected with several common swine pathogens. PROCEDURE: Pigs (7 to 10 days old) were weaned and segregated from the farm of origin and compared with littermate control pigs (14 to 17 days old) that were weaned and raised on-site. Pig weight was measured and microbial flora were isolated at 14-day intervals for 84 days, beginning when the pigs were 7 to 10 days old. RESULTS: At 50 days of age, the segregated, early weaned pigs had a mean weight of 23.7 kg, compared with a mean weight of 12.5 kg for control pigs. Pasteurella multocida was isolated from fewer segregated, early weaned pigs than from controls. Signs of Mycoplasma hyopneumoniae infection were detected in control pigs but not in segregated early weaned pigs. Clinical, serologic, or bacteriologic signs of early postnatal vertical transmission of Actinobacillus pleuropneumoniae were not detected in either group. CLINICAL IMPLICATION: Vertical transmission of M hyopneumoniae was prevented by weaning pigs at 7 to 10 days of age and segregating them off-site, without the use of medication. Although medicated controls were not compared, results from this herd revealed that use of antibiotics is not the most important factor for disease control in segregated, early weaning programs. Minimizing antibiotic use in disease-control protocols reduces costs as well as removes the need for extra-label drugs.