Individual risk factors for Mycoplasma hyopneumoniae infections in suckling pigs at the age of weaning

Abstract

BackgroundIn recent years, the occurrence and the relevance of Mycoplasma hyopneumoniae infections in suckling pigs has been examined in several studies. Whereas most of these studies were focused on sole prevalence estimation within different age groups, follow-up of infected piglets or assessment of pathological findings, none of the studies included a detailed analysis of individual and environmental risk factors. Therefore, the aim of the present study was to investigate the frequency of M. hyopneumoniae infections in suckling pigs of endemically infected herds and to identify individual risk factors potentially influencing the infection status of suckling pigs at the age of weaning.ResultsThe animal level prevalence of M. hyopneumoniae infections in suckling pigs examined in three conventional pig breeding herds was 3.6% (41/1127) at the time of weaning. A prevalence of 1.2% was found in the same pigs at the end of their nursery period. In a multivariable Poisson regression model it was found that incidence rate ratios (IRR) for suckling pigs are significantly lower than 1 when teeth grinding was conducted (IRR: 0.10). Moreover, high temperatures in the piglet nest during the first two weeks of life (occasionally >40°C) were associated with a decrease of the probability of an infection (IRR: 0.23-0.40). Contrary, the application of PCV2 vaccines to piglets was associated with an increased infection risk (IRR: 9.72).ConclusionsSince single infected piglets are supposed to act as initiators for the transmission of this pathogen in nursery and fattening pigs, the elimination of the risk factors described in this study should help to reduce the incidence rate of M. hyopneumoniae infections and thereby might contribute to a reduced probability of high prevalences in older pigs.

Current Status of <i>M. hyopneumoniae</i> in Pigs in Grenada, West Indies

“…Females under the age of 1 year are more strongly affected. Our findings are in agreement with Nathues et al [19] who also reported gender difference in the incidence of Mycoplasma hyopneumoniae in suckling pigs. They found 56.1% incidence in females compared to 43.9% in males.…”

“…A total number of 459 samples were tested from pigs for M. hyopneumoniae, out also reported more seropositivity in younger age pigs [9] [18] [19]. In another study Grosse et al [20] found older sows in some herds in Germany more often seropositive than younger ones.…”

“…The researchers used PCR on nasal swabs [18] [23], various serological tests [9] [22], bacterial cultures of lung tissue and combination of tests. Nathues et al [19] used a combination of PCR on nasal swabs and ELISA for antibodies in serum. Makhanon et al [24] compared the results of culture and PCR in various tissues of slaughtered pigs for the detection of different species of Mycoplasma.…”

Modelling the within-herd transmission of Mycoplasma hyopneumoniae in closed pig herds

“…2). The function parameters were selected in order to reproduce observed prevalence of M. hyopneumoniae infections in suckling pigs [22]. …”

“…The likelihood of transmission of M. hyopneumoniae from sows to their offspring increased exponentially with the length of the suckling period, which is equal to the time under exposure [22, 26, 27]. Two scenarios assuming a length of the suckling period equal to 21 and 28 days, respectively, were tested.…”