The use of non-therapeutic antibiotics as animal feed additives has raised public health concerns due to the increasing resistance of pathogens to antibiotics. It is therefore required to develop safe and effective alternative feed additives to replace non-therapeutic antibiotics. The aim of this study was to assess the effects of the multiherbal compound, KIOM-C, on growth performance and immune response of growing-to-finishing pigs under farm conditions. The experimental trials were performed in a Korean commercial swine growing-to-finishing complex, and a total of 70-day-old 160 pigs were selected. Eighty pigs were treated with KIOM-C at the level of 2 kg/tonne until slaughter age (KT group), while another 80 pigs were not treated with KIOM-C (NT group). All animals were vaccinated against foot-and-mouth disease (FMD) at 60 and 110 days of age. During the trial period, average daily weight gain (ADWG), average daily feed intake (ADFI), feed conversion ratio (FCR), survival rates, and average slaughter ages were measured. The serum concentrations of tumor necrosis factor-a (TNF-α), interferon-γ (IFN-γ), and IgA were also evaluated. In order to evaluate specific humoral immune responses, the foot-and-mouth disease virus (FMDV) serotype O-specific antibody was measured. The ADWG, ADFI, and FCR of the KT group were significantly greater than those of the NT group (p<0.05). Serum concentrations of IgA in the KT group was statistically higher than the NT group. The antibody levels of the KT group against FMDV serotype O was higher than the NT group, and 86.67% of the KT group tested positive for anti-FMDV antibodies. Overall, these findings suggest that KIOM-C improves growth performance and immune response of pigs under growing-to-finishing farm conditions, and implies that the herbal compound may be used as a suitable alternative feed additive.

Rotaviruses are enteric pathogens causing acute watery dehydrating diarrhea in humans and animals. The importance of group C rotavirus (GpC-RV) infections has not been established as the studies on the GpC-RV have been hampered by the lack of an in vitro culture system. However, diarrheal diseases associated with GpC-RV have been gradually increasing worldwide. In this study, VP6 gene of bovine GpC-RV Korean isolate was expressed, and monoclonal antibodies (mAbs) against VP6 were produced and characterized. The VP6 gene was cloned and expressed based on a baculovirus expression system. Indirect fluorescence antibody (IFA), polymer chain reaction (PCR), and Western blot assays were used to confirm expression of VP6 gene synthesized by the recombinant baculovirus. Eleven mAbs against VP6 were produced using expressed VP6. Cross-reactivity of the mAbs was assessed with recombinant VP6 proteins from porcine GpC-RV and human GpA-RV, or different serotypes of group A rotavirus strains by IFA test. Some mAbs reacted with intact porcine GpC-RV Cowden strain as well as bovine GpC-RV VP6 recombinant baculoviruses, but not with human and animal GpA-RV strains. The VP6-specific mAbs might be useful to develop immunodiagnostic tests such as rapid diagnostic kit, IFA and enzyme-linked immunosorbent assay (ELISA) for detection of GpC-RV.

Norovirus (NoV) is an etiologic agent of human and animal acute gastroenteritis and is a member of the family Caliciviridae. NoV is classified based on nucleotide sequences of the VP1 gene into at least six genogroups (GI-GVI), among which GI, GII, and GIV are known to infect humans and GII is the most prevalent genogroup. In this study, VP1, the full gene of GII human NoV, was cloned from a human fecal sample and expressed using a baculovirus expression system. Human NoV VP1-specific monoclonal antibodies (MAbs) were produced using expressed recombinant VP1. Expressed VP1 in the recombinant virus was confirmed by polymerase chain reaction (PCR), indirect fluorescence antibody (IFA) test, and Western blot analysis. Eight hybridomas secreting VP1-specific MAbs against human GII NoV were generated and characterized. All of the MAbs produced in this study reacted with human GII NoV VP1-recombinant baculoviruses but not with other non-human calicivirus recombinant baculoviruses. These MAbs reacted specifically with human NoV GII.4-2009 virus-like particles (VLPs), and some MAbs showed cross-reactivity with other GII.4 variant VLPs. Expressed human GII NoV VP1-recombinant protein and MAbs specific to this protein can be used as useful reagents for detecting and characterizing human NoV.