Ruminal microbiome and fermentation associated with the gastrointestinal nematode Haemonchus contortus
K. Mikulová1, D. Petrič1, D. Batťanyi1, M. Várady2, Z. Váradyová1
1 Institute of Animal Physiology of Centre of Biosciences, Slovak Academy of Sciences, Šoltésovej 4-6, 04001 Košice, Slovakia, 2 Institute of Parasitology, Slovak Academy of Sciences, Hlinková 3, 04001 Košice, Slovakia; email@example.com
We investigated the ruminal microbiota and fermentation patterns of lambs infected and non-infected with the gastrointestinal parasitic nematode Haemonchus contortus in vivo and in vitro. Twelve parasite-free lambs were divided into two groups: a control group (CON) with six uninfected lambs and an experimental group (EXP) with six lambs inoculated with 5000 infective H. contortus larvae. At 48, 49- and 50 days post-infection, sheep were sampled with their corresponding uninfected controls for histological analysis, and rumen fluids were collected for in vitro experiment, pH measurement, ruminal short-chain fatty acids, and microbial community isolation. The ruminal contents, fermentation parameters, and microbiome in vitro and in vivo were determined using molecular and microscopic techniques. Ruminal fermentation characteristics and methane production were affected by infection in vivo and in vitro (p < 0.05). The populations of Archaea (p < 0.05), Methanomicrobiales (p < 0.05), and Methanobacteriales (p < 0.05) were significantly higher for the EXP than the CON group. Total protozoa in the lambs did not differ significantly (p > 0.05) between the groups. During the parasitic load of the H. contortus pH increased in the rumen and the abomasum. Subsequently, there was a change in the microbial community of the abomasum, mainly an increase in the anaerobic microbial mass, and at the same time changes in the representation of individual microbial species. The study was supported by the Slovak Research and Development Agency (APVV 18-0131).