Objective—To assess the role of noncommercial pigs in the epidemiology of porcine reproductive and respiratory syndrome (PRRS) virus.
Design—Seroepidemiologic study and survey study.
Animals—661 pigs from which blood samples were collected at slaughter and 32 pigs from which blood samples were collected longitudinally.
Procedures—Spatial databases of commercial farms and 4-H participation were evaluated by use of commercial geographic information systems software. Information on disease knowledge and management methods of 4-H participants was obtained by mail survey and personal interview. Serum samples for antibody testing by PRRS ELISA were obtained from pigs at slaughter or at county fairs and on farms.
Results—Participation in 4-H swine programs was geographically associated with commercial swine production in Minnesota, and 39% of 4-H participants reared pigs at locations with commercial pigs. High seroprevalence at fairs (49%; range, 29% to 76%) and seroconversion after fairs indicated that PRRS virus exposure was common in pigs shown by 4-H participants and that transmission could occur at fairs.
Conclusions and Clinical Relevance—The small swine population shown by 4-H members (estimated 12,000 pigs) relative to the population of commercial swine in Minnesota (estimated 6.5 million pigs) suggested the former overall was likely of minor importance to PRRS virus epidemiology at present. However, the relative frailty of knowledge of biosecurity practices, evidence that PRRS virus exposure was frequent, common intentions to show pigs at multiple events, and often close interactions with commercial herds suggested that the 4-H community should be involved in regional efforts to control PRRS.
Objective—To determine whether withholding feed
from pigs prior to slaughter had any effects on meat
quality, percentage of pigs with Salmonella spp in
cecal contents during slaughter, or percentage of pigs
with lacerations of the gastrointestinal tract during
Procedures—At the finishing barn, pigs were
assigned to 30 pens. Feed withdrawal times were
assigned to pens at random, and pigs in each pen
were marketed in 3 groups. The first marketing group
consisted of the 10 heaviest pigs in each pen, the
second consisted of the next 10 heaviest pigs, and
the third consisted of all remaining pigs.
Results—Withdrawing feed improved the redness
score assigned to the meat but did not have any other
significant effects on carcass composition or meat
quality. The percentage of pigs with Salmonella spp in
the cecal contents decreased from the first (73%) to
the second (64%) to the third (52%) marketing group.
However, isolation of Salmonella spp from cecal contents
was not associated with feed withdrawal time
or with pen prevalence of Salmonella shedding during
the 2 months prior to slaughter. Feed withdrawal time
and marketing group did not have any significant
effects on overall prevalence of gastrointestinal tract
Conclusions and Clinical Relevance—Results suggest
that withdrawal of feed from pigs prior to slaughter
does not increase the prevalence of Salmonella
colonization or the risk of carcass contamination associated
with gastrointestinal tract lacerations during
slaughter but only slightly enhances meat quality.
(J Am Vet Med Assoc 2002;220:497–502)
Objective—To determine whether withdrawing feed
from pigs prior to slaughter had any effects on prevalence
or severity of gastric ulcers.
Procedures—At the finishing barn, pigs were assigned
to 30 pens. Feed withdrawal times (0, 12, or 24 hours)
were assigned to pens at random, and pigs in each pen
were marketed in 3 groups over a period of 4 weeks.
The first marketing group consisted of the 10 heaviest
pigs in each pen, the second consisted of the next 10
heaviest, and the third consisted of all remaining pigs.
Feed was withheld from all pigs in each pen prior to
removal of each marketing group. Thus, feed was withheld
once, twice, or 3 times for pigs in the first, second,
and third marketing groups, respectively.
Results—Feed withdrawal time was not significantly
associated with ulcer score at the time of slaughter.
Ulcer scores and prevalence of chronic damage were
higher in the third marketing group, regardless of
feed withdrawal time. Prevalence of severe damage,
prevalence of chronic damage, and prevalence of
esophageal constriction increased as carcass weight
decreased. No pigs died of gastric ulceration.
Conclusion and Clinical Relevance—Results suggest
that withdrawal of feed from pigs prior to slaughter
does not increase damage to the stomach and that
repeated feed withdrawal does not result in fatal gastric
ulceration. (J Am Vet Med Assoc 2002;220:503–506)
Recent state and federal legislative actions and current recommendations from the World Health Organization seem to suggest that, when it comes to antimicrobial stewardship, use of antimicrobials for prevention, control, or treatment of disease can be ranked in order of appropriateness, which in turn has led, in some instances, to attempts to limit or specifically oppose the routine use of medically important antimicrobials for prevention of disease. In contrast, the AVMA Committee on Antimicrobials believes that attempts to evaluate the degree of antimicrobial stewardship on the basis of therapeutic intent are misguided and that use of antimicrobials for prevention, control, or treatment of disease may comply with the principles of antimicrobial stewardship. It is important that veterinarians and animal caretakers are clear about the reason they may be administering antimicrobials to animals in their care. Concise definitions of prevention, control, and treatment of individuals and populations are necessary to avoid confusion and to help veterinarians clearly communicate their intentions when prescribing or recommending antimicrobial use.