Effects of and factors associated with umbilical hernias in a swine herd.
Of 2,958 pigs from a 320-sow, farrow-to-finish herd that were evaluated from birth to slaughter, 44 (1.5%) developed umbilical hernias. Hernias were detected mostly (34/44) when the pigs were between 9 and 14 weeks of age and were not fatal despite lack of treatment. Among littermates, weight gain prior to weaning was significantly (P = 0.04) lower in pigs that developed hernias (144.7 g/d) by 30 weeks of age than for nonaffected pigs (163.3 g/d), but growth rates from weaning to about 45 kg did not differ significantly. Records of pigs sired by 13 purebred boars were used to evaluate breed-of-sire associations. Pigs sired by American Spotted (n = 19; relative risk [RR] = 8.3; 95% confidence interval [CI] = 2.1 to 32.7) and Duroc boars (n = 378; RR = 2.1; 95% CI = 1.0 to 4.5) were more likely to develop umbilical hernias than were pigs (n = 1,644) sired by Yorkshire boars. Umbilical lesions (omphalitis or umbilical abscess) were associated (RR = 7.6; 95% CI = 1.2 to 49.5) with umbilical herniation on an individual basis, but the association was not evident (RR = 1.2; 95% CI = 0.2 to 7.6) when the litter was the unit of analysis. Analysis of sire associations, stratified by umbilical lesion status, indicated increased risks in the nonlesioned stratum for the American Spotted (RR = 8.7) and Duroc sires (RR = 2.2). Adequate comparisons of sire breed in the lesioned stratum could not be made, because umbilical lesions were an infrequent finding (9/2, 958).(ABSTRACT TRUNCATED AT 250 WORDS)
Searcy-Bernal
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Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis.
Gardner
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Hird
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D000818:Animals; D001947:Breeding; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D006554:Hernia, Umbilical / Q000453:epidemiology / Q000235:genetics / Q000401:mortality / Q000662:veterinary*; D015994:Incidence; D008297:Male; D016012:Poisson Distribution; D011446:Prospective Studies; D012307:Risk Factors; D012737:Sex Factors; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D015430:Weight Gain