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Prof. Eva-Maria Saliu, PhD, Organic animal husbandry, Eberswalde University for Sustainable Development

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There is a strong relationship between nutrient digestibility and pig performance as shown previously by us (1,2). A. suum infected pigs display reduced body weight gain and recent work suggests the involvement of reduced intestinal nutrient uptake (3-5) which may act together with reduced feed intake and feed conversion (6,7). It is thus conceivable that metabolic perturbations associated with the energy intensive characteristics of the Ascaris parasite physiology and tissue repair requirements (intestine, liver and lung damage due to larval migration; rapid growth into adult worms > 30 cm; release of >2x105 eggs per female/day) impose significant challenges not only for overall pig performance, but also for immune responses to unrelated parties such as vaccines and opportunistic pathogens. Furthermore, A. suum infection results in significant shifts in the composition of the intestinal microbiota, which may affect fermentation processes and energy supply for the host (8). Our preliminary unpublished data indicate that elevated microbial metabolites derived from a highly fermentable fiber in the pig diet licenses stronger mucosal immune responses, resulting in impaired A. suum growth. Our published work further demonstrates that the dams’ microbiota is important for the development of the piglets’ microbiome and fosters resilience of suckling pigs against infections (9). In addition, we observed a strong positive correlation of maternal and piglet immunoglobulins and an impact on the intestinal barrier function (10). Along that line, our work in broiler chicken revealed protective effects of parent vaccination on the offspring of chicken, resulting in the modification of the microbiota, altered signature profiles of microbial metabolites, and, consequently, improved performance (11).

The DR projects will therefore dissect the consequences of A. suum infection at the mucosal interfaces by 1) determination of the humoral anti-viral vaccine response and resilience to lung pathogens in A. suum infected pigs, and 2) deciphering the impact of intestinal barrier repair/integrity, nutrient uptake and pig performance in piglets exposed to A. suum early vs. late in life.

Both DRs will perform mechanistic in vitro laboratory work in simplified models (e.g. cell culture, gene expression, organoids) and then pursue animal trials embedded in the regular production cycle of an organic pig farm in Brandenburg (sows, suckling and weaned piglets, fattening pigs in indoor/outdoor pens) to address the complex system. An A. suum free conventional farm will serve as control. 

References:
1) Saliu et al. 2024, doi: 10.1080/1745039X.2024.2368284; 2) Ellner et al. 2021, doi: 10.1080/1745039X.2021.1958647; 3) Koehler et al. 2022, doi: 10.1186/s13071-021-05029-1; 4) Clark et al. 2003; 5) Boes et al. 2010, doi: 10.1016/j.vetpar.2010.05.007; 6) Forsum et al. 1981, doi: 10.1017/S0031182000080483; 7) Thamsborg et al. 2013, doi: 10.1016/B978-0-12-396978-1.00014-8; 8) Midha et al. 2022, doi: 10.1186/s40168-022-01399-5; 9) Grześkowiak et al. 2022 doi: 10.1007/s00284-022-02848-y; 10) Grześkowiak et al. 2023, doi : 10.1016/j.animal.2022.100697; 11) Fuhrmann et al. 2022b doi: 10.3390/antibiotics11121703; 12) Brodkorb et al. 2019, doi: 10.1038/s41596-018-0119-1; 13) Pérez-Burillo et al., 2021 doi: 10.1038/s41596-021-00537-x.