Department of Animal Health

Reproductive efficiency in male livestock is essential for sustainable animal production; however, the use of synthetic reproductive drugs is constrained due to its, harmful side effects, antimicrobial resistance and effect on long-term reproductive health. Therefore, use of plant extracts to enhance reproductive performance in livestock has gained attention because of their bioactive compounds, affordability, and reduced side effects compared to synthetic drugs. The review analyses the impact of specific plants in sub-Saharan Africa (SSA) on male reproductive performance, concentrating on libido, testicular function, hormonal levels, and semen quality. Moringa oleifera and Zingiber officinale improve libido, testicular function, hormonal status, and semen quality of male animals. The bioactive components of those plants, including flavonoids, alkaloids, tannins, and saponins, have antioxidant, anti-inflammatory, and hormone-modulating effects that collectively improve reproductive outcomes. Further research is needed to optimise dosage, ensure safety, and promote the sustainable use of these plants to prevent over exploitation of specific species. Furthermore, the sustainable use of reproductive improving plants requires their cultivation, nursery development, farmer training, and community level processing to improve availability, quality control and economic value. Male animals can access these plants through managed browsing or grazing, cut and drying leaves and controlled supplementation, supported by separation of male animals to regulate breeding and accurately assess reproductive effects.

Bumped kinase inhibitors (BKIs) have demonstrated safety and promising efficacy against various apicomplexan pathogens both in vitro and in vivo, but do not act parasiticidal in vitro. In the closely related cyst-forming coccidians Toxoplasma gondii, Neospora caninum and Besnoitia besnoiti, treatments with BKI-1708 induce the conversion of intracellular tachyzoites into atypical multinucleated complexes named "baryzoites". In this study, we comparatively assessed tachyzoites and baryzoites of all three species with respect to ultrastructure, differential antigen expression by immunofluorescence, and overall differential protein expression by MS-proteomics. TEM demonstrated common, but also distinguishing, structural features in baryzoites of the three species. They contained newly formed zoites, unable to complete cytokinesis, and thus they were trapped intracellularly. An electron-dense cyst wall-like structure was found only in T. gondii baryzoites. Species-specific differences in antigen expression were observed by immunofluorescence. Comparative proteomic analysis of baryzoites versus tachyzoites revealed a downregulation of ribosomal proteins, proteins associated with secretory organelles, as well as of transcription and translation factors in baryzoites across all species. Bradyzoite-specific markers were upregulated only in T. gondii baryzoites. Two alveolin-domain filament proteins and a hypothetical protein (TGME49_236950, NCLIV_050850, BESB_060040) were detected at higher abundance in all three species. Thus, baryzoites exhibit distinct phenotypic and proteomic profiles, with ambiguous expression of tachyzoite and bradyzoite antigens, suggesting a reversible response to stress rather than progression into a fully differentiated form.

Data from Serrated Hinged Terrapin (SHT) and African Spurred Tortoise (AST) strains of tortoise and their crosses were used to assess the influence of parity on clutch traits of breeding tortoises. A total of forty-five (45) breeder tortoises (5 Sires and 40 Dams) were used to constitute the three mating groups. The mating groups were: SHT x SHT, AST x AST, and SHT x AST. The mating ratio was 1 male to 4 females. Five parities per female per mating group were monitored, giving a total of sixty (60) clutch sizes. Records were obtained on clutch sizes and weights at hatchling and juvenile stages. The clutch size trend in AST x AST was similar to that of SHT x SHT, with the highest clutch size recorded in the first parity. The level of heterosis in clutch size at hatchling was 4.63% this value, though relatively low, reflects a better genetic constitution of the crossbred than the parents. Clutch weight recorded at third and fifth parities with clutch sizes of 5.6 and 4.6, respectively, was higher than the corresponding weight for the clutch size of 6.5; the trend differs within the AST x AST group. Clutch size at the juvenile stage ranged between 4.3 and 8.3 for SHT x SHT, with a mean of 6.3. Significant (p<0.05) differences within parities were recorded for clutch size at hatchling and juvenile stages for the SHT x SHT breed. Conclusively, any of the three genotypes may be kept for optimum production, although the crossbred exhibited better performance numerically.

To gain insight into the common pathogenic, bacterial zoonosis represented by Salmonella infections in poultry and humans, we acted to determine salmonellosis prevalence in poultry and humans in Nigeria mapping hotspots. Using multi-sourced data, we conducted a meta-analysis to determine national and sub-national prevalence of salmonellosis in poultry from 2000 until 2020. Bayesian spatial joint modelling was used to map Non-Typhoidal Salmonella (NTS) infections in humans and poultry using climatic and demographic predictor variables. With the overall prevalence in poultry at 31.6%, the highest state-level prevalence rates were seen in Ogun (70.2%), Lagos (61.8%), Zamfara (58.2%) and Bauchi (57.1%). The North-West, South-West and South-South regions of Nigeria have the highest regional-level prevalence in poultry amounting to 38.5%, 36.9% and 33.6%, respectively. Thirteen states have higher than the average national prevalence (31.6%). While we found a negative association between NTS in humans and in poultry, the prevalence of diarrhoea in humans positively predicted salmonellosis in poultry. Not surprisingly, poultry populations positively predicted salmonellosis in other poultry populations. Higher numbers of human cases were predicted in the North, with more poultry cases in the South and in some North-Eastern states. The observed human NTS-poultry salmonellosis correlation is counterfactual to logic and plausibility as high poultry density and contamination in poultry are expected to predict human infection. The outcome pointed to under-reporting linked to self-treatment, under-testing in the public health and veterinary laboratory and lack of uniform primary healthcare services, particularly in under-served areas of Nigeria. Salmonellosis continues to be a serious burden, and provision of better health data is needed.

Chemotherapy of leishmaniasis, both human and canine, is far from ideal and new antileishmanial drugs are urgently needed. Therapeutic arsenal against the disease is old, of low antileishmanial efficacy and hampered by toxicity issues in some cases. Furthermore, hospitalization required for some drugs, the price of the safer presentations is high and there are growing reports of leishmanial resistance to first line medicines. In addition to human visceral cases, canine infections by Leishmania infantum represent a first order veterinary pathology with dogs being the main reservoir for this zoonotic infection. Thus, dog infections by L. infantum are needed to develop veterinary drugs and are the best surrogate model for human leishmaniasis. Many contributions on the efficacy of new drugs or presentations in dogs have been published but the variety of experimental designs makes comparisons challenging thus reducing their value. Present study offers a comprehensive review of canine experimental infections with visceral Leishmania , with a particular focus on L. infantum . The review encompasses a range of topics, including animal housing, regulatory aspects, ethical considerations, infection methods, follow-up procedures, and outcomes. The final aim of our contribution is to promote the standardization of some experimental procedures to enhance the comparability of the studies performed. This, in turn, is expected to reduce the use of animals and to increase the efficiency of drug discovery and development.

Vaccination is an essential tool for controlling the severity of influenza in swine and its spillover risk to humans. Due to fast mutation rates, genomic reassortment, and the high antigenic variability of influenza A viruses (IAV), it is necessary to update vaccine strains to better match and neutralize circulating viruses. In this study, we analyzed the immune cross-reactivity of hemagglutination inhibition (HI) antibodies induced by currently approved European swine influenza vaccines against Spanish swine influenza viruses (SIVs) isolated from 2016 to 2021, as well as human IAV strains, using a murine model. Sera from immunized mice with monovalent (MVV) or trivalent (TVV) swine influenza vaccines were tested against Spanish representative SIVs carrying HAs from different subtypes and lineages using a HI serological assay. Amino acids in the antigenic motifs of the receptor binding site (RBS) of the IAV HA were compared and contrasted among SIV strains to detect changes that may affect protein antigenicity. Sera from mice immunized with MVV or TVV showed no HI antibodies against a 2019 Eurasian avian-like H1 (EAswH1) SIV. TVV did not induce cross-reactive HI antibodies against two human seasonal H3 SIV from the 2000s (2000s-like H3) or against the human seasonal H3 vaccine strain (HuVacH3). Geometric mean (GM) HI titers of sera from TVV-immunized mice were below the protection threshold (GM < 40) against the recent human seasonal-like H1 (HUswH1) SIV, against an EAswH1 SIV, and against the human seasonal H1 vaccine strain (HuVacH1). HI antibodies induced by MVV showed high cross-reactivity with a 2019 EAswH1 SIV isolate. Currently authorized vaccines do not induce HI antibodies against some contemporary SIV circulating in Spain, nor against human seasonal influenza vaccine strains. Updating vaccine strains to better match new SIVs emerging in Spanish swine is warranted.