Development and characterization of a novel nanobody with SRMV neutralizing activity.

Peste des petits ruminants (PPR) is an acute, contact infectious disease caused by the small ruminant morbillivirus (SRMV), and its morbidity in goats and sheep can be up to 100% with significant mortality. Nanobody generated from camelid animals such as alpaca has attracted wide attention because of its unique advantages compared with conventional antibodies. The main objective of this study was to produce specific nanobodies against SRMV and identify its characteristics. To obtain the coding gene of SRMV-specific nanobodies, we first constructed an immune phage-displayed library from the VHH repertoire of alpaca that was immunized with SRMV-F and -H proteins. By using phage display technology, the target antigen-specific VHHs can be obtained after four consecutive rounds of biopanning. Results showed that the size of this VHH library was 2.26 × 1010 CFU/mL and the SRMV-F and -H specific phage particles were greatly enriched after four rounds of biopanning. The positive phage clones were selected and sequenced, and total of five independent different sequences of SRMV-specific nanobodies were identified. Subsequently, the DNA fragments of the five nanobodies were cloned into E. coli BL21(DE3), respectively, and three of them were successfully expressed and purified. Specificity and affinity towards inactivated SRMV of these purified nanobodies were then evaluated using the ELISA method. Results demonstrated that NbSRMV-1-1, NbSRMV-2-10, and NbSRMV-1-21 showed no cross-reactivity with other antigens, such as inactivated BTV, inactivated FMDV, His-tag labeled protein, and BSA. The ELISA titer of these three nanobodies against inactivated SRMV was up to 1:1000. However, only NbSRMV-1-21 displayed SRMV neutralizing activity at a maximum dilution of 1:4. The results indicate that the nanobodies against SRMV generated in this study could be useful in future applications. This study provided a novel antibody tool and laid a foundation for the treatment and detection of SRMV.

Morphological and physiological features in small ruminants: an adaptation strategy for survival under changing climatic conditions.

Climate change due to natural human activity is a significant global phenomenon affecting the sustainability of most countries' livestock industries. Climate change factors such as ambient temperature, relative humidity, direct and indirect sun radiation, and wind have significant consequences on feed, water, pasture availability, and the re-emergence of diseases in livestock. All these variables have a considerable impact on livestock production and welfare. However, animals' ability to respond and adapt to changes in climate differs within species and breeds. Comparatively, small ruminants are more adaptive to the adverse effects of climate change than large ruminants in terms of reproduction performance, survival, production yield, and resistance to re-emerging diseases. This is mainly due to their morphological features against harsh climate effects. Tropical breeds are more adaptive to the adverse effects of climate change than small temperate ruminants. However, the difference in morphological characteristics towards adaptation to the impact of climate change will guide the development of suitable policies on the selection of breeding stock suitable for different regions in the world. The choice of breeds based on morphological features and traits is an essential strategy in mitigating and minimizing the effects of climate change on small ruminants' production and welfare. This review highlights the adaptive morphological features within and among breeds of small ruminants toward adaptation to climate change.

Exploratory study for implementing a Global Burden of Animal Diseases case study in Senegal. / Etude exploratoire pour la mise en oeuvre d'une étude de cas du programme " Impact mondial des maladies animales " au Sénégal.

Senegal is a West African country with both extensive animal production systems, representative of the environmental, economic and animal health constraints specific to the Sahel region, and thriving commercial poultry and dairy production. An exploratory study was conducted in Senegal between 2021 and 2022 as a prelude to a case study of the Global Burden of Animal Diseases (GBADs) programme. An overview of existing animal production systems as well as the main priorities and issues in animal health on a national level was developed. A national workshop gathering representatives from the livestock production and academic sectors took place in Dakar in June 2022 with the objective of jointly developing a case study. The participants prioritised pastoralist production systems for cattle and agropastoral systems for small ruminants for the application of the GBADs programme. Through a series of activities, the participants highlighted the health, environmental, economic and socio-political challenges surrounding these systems, all of which limit their contribution to the well-being of pastoralist households, consumers and other stakeholders. While Senegal has in the past hosted a large number of research and cooperative projects on these two livestock systems, participants noted difficulties in obtaining, centralising and harmonising the existing data. This exploratory study led to the funding of a focused case study of the agropastoral small-ruminant sector that was carried out in 2023 in partnership with national and international organisations.

Le Sénégal est un pays d'Afrique de l'Ouest comprenant à la fois des systèmes de production animale extensifs représentatifs des contraintes environnementales, économiques et sanitaires propres à la zone sahélienne, et un élevage commercial avicole et laitier en plein essor. Une étude exploratoire en prélude à une étude de cas du programme " Impact mondial des maladies animales " (GBADs) a été menée au Sénégal sur la période 2021-2022. Un état des lieux des systèmes de production animale existants, ainsi que des principales priorités et questions en termes de santé animale au niveau national, a été dressé. Un atelier national rassemblant des représentants de l'administration des productions animales et du secteur académique a eu lieu à Dakar en juin 2022 avec pour objectif de construire l'étude de cas de manière concertée. Les participants ont donné la priorité aux systèmes d'élevage bovins pastoral et petits ruminants agropastoral pour l'application du programme GBADs. Par une série d'activités, les participants ont mis en évidence les enjeux sanitaires, environnementaux, économiques et socio-politiques autour de ces systèmes qui limitent leur contribution au bien-être des ménages d'éleveurs, de consommateurs et autres acteurs de la société. Si le Sénégal a accueilli par le passé un grand nombre de projets de recherche et de coopération portant sur les deux systèmes d'élevage, les participants ont fait remonter les difficultés à obtenir, centraliser et harmoniser les données existantes. Cette étude exploratoire a débouché sur le financement d'une étude de cas focalisée sur le secteur agropastoral des petits ruminants, réalisée en 2023 en partenariat avec des organisations nationales et internationales.

Senegal es un país de África occidental con sistemas de producción animal extensivos, representativos de las limitaciones ambientales, económicas y zoosanitarias propias de la región del Sahel, y una próspera producción comercial avícola y lechera. Entre 2021 y 2022, se llevó a cabo en Senegal un estudio exploratorio como paso previo a la realización de un estudio de caso en el marco del programa sobre el impacto global de las enfermedades animales (GBADs). Se elaboró una reseña de los sistemas de producción animal existentes, así como de las principales prioridades y cuestiones en materia de sanidad animal a escala nacional. En junio de 2022, se celebró en Dakar un taller nacional que reunió a representantes del sector de la producción ganadera y el sector académico con el objetivo de elaborar conjuntamente un estudio de caso. Los participantes priorizaron los sistemas de producción pastoral de ganado vacuno y los sistemas agropastorales de pequeños rumiantes para la aplicación del programa GBADs. A través de una serie de actividades, los participantes pusieron de relieve los retos sanitarios, ambientales, económicos y sociopolíticos en torno a dichos sistemas, que limitan su contribución al bienestar de los hogares pastorales, los consumidores y otras partes interesadas. Aunque Senegal ha acogido en el pasado un gran número de proyectos de investigación y cooperación sobre estos dos sistemas ganaderos, los participantes señalaron las dificultades para obtener, centralizar y armonizar los datos existentes. Este estudio exploratorio condujo a la financiación de un estudio de caso centrado en el sector agropastoril de pequeños rumiantes que se llevó a cabo en 2023 en colaboración con organizaciones nacionales e internacionales.

Udder health, bacterial isolation and antimicrobial sensitivity of Staphylococcus species from non-dairy goats on smallholder farms in Hong Kong.

This research article describes an investigation into the udder health, bacterial isolation and antimicrobial sensitivity of three staphylococcal species isolated from the milk of non-dairy goats, suckling their kids, on two smallholder farms in the Hong Kong Special Administrative Region. Udder lesions were visually noted in 21 of 34 goats and two goats had palpable abnormalities. Collected milk samples grew a total of 11 bacterial organisms and the most frequently isolated organism was Staphylococcus chromogenes. Selected isolates of S. aureus, caprae and simulans from both farms were tested by antimicrobial sensitivity testing for 23 antimicrobials and all isolates showed antimicrobial resistance to doxycycline and tetracycline. Less common resistance was shown to ampicillin, chloramphenicol, penicillin and rifampicin. This preliminary study confirms the presence of udder lesions and mastitis bacteria in non-dairy goats in Hong Kong, along with the first information on the antimicrobial profile of three common Staphylococcus species bacteria affecting goats.

Domain Organization of Lentiviral and Betaretroviral Surface Envelope Glycoproteins Modeled with AlphaFold.

The surface envelope glycoproteins of nonprimate lentiviruses and betaretroviruses share sequence similarity with the inner proximal domain ß-sandwich of the human immunodeficiency virus type 1 (HIV-1) gp120 glycoprotein that faces the transmembrane glycoprotein as well as patterns of cysteine and glycosylation site distribution that points to a similar two-domain organization in at least some lentiviruses. Here, high-reliability models of the surface glycoproteins obtained with the AlphaFold algorithm are presented for the gp135 glycoprotein of the small ruminant caprine arthritis-encephalitis (CAEV) and visna lentiviruses and the betaretroviruses Jaagsiekte sheep retrovirus (JSRV), mouse mammary tumor virus (MMTV), and consensus human endogenous retrovirus type K (HERV-K). The models confirm and extend the inner domain structural conservation in these viruses and identify two outer domains with a putative receptor binding site in the CAEV and visna virus gp135. The location of that site is consistent with patterns of sequence conservation and glycosylation site distribution in gp135. In contrast, a single domain is modeled for the JSRV, MMTV, and HERV-K betaretrovirus envelope proteins that is highly conserved structurally in the proximal region and structurally diverse in apical regions likely to interact with cell receptors. The models presented here identify sites in small ruminant lentivirus and betaretrovirus envelope glycoproteins likely to be critical for virus entry and virus neutralization by antibodies and will facilitate their functional and structural characterization. IMPORTANCE Structural information on the surface envelope proteins of lentiviruses and related betaretroviruses is critical to understand mechanisms of virus-host interactions. However, experimental determination of these structures has been challenging, and only the structure of the human immunodeficiency virus type 1 gp120 has been determined. The advent of the AlphaFold artificial intelligence method for structure prediction allows high-quality modeling of the structures of small ruminant lentiviral and betaretroviral surface envelope proteins. The models are consistent with much of the previously described experimental data, show regions likely to interact with receptors, and identify domains that may be involved in mechanisms of antibody neutralization resistance in the small ruminant lentiviruses. The models will allow more precise design of mutants to further determine mechanisms of viral entry and immune evasion in this group of viruses and constructs for structural determination of these surface envelope proteins.

Small ruminant lentivirus capsid protein (SRLV-p25) antigenic structural prediction and immunogenicity to recombinant SRLV-rp25-coupled to immunostimulatory complexes based on glycyrrhizinic acid.

Small ruminant lentiviruses (SRLV) infect sheep and goats resulting in significant economic losses. This study evaluated for the first time the predicted conformational structure of the SRLV-capsid-protein 25 (SRLV-p25) and analyzed the antigenicity of recombinant protein (SRLV-rp25) in mice by coupling to an immunostimulatory complexes based on glycyrrhizinic acid liposomes (GAL) and tested plasma from goats and sheep naturally infected. Analysis in silico and conformational structure of SRLV-p25 (genotype B-FESC-752) showed similar characteristics to other lentiviral capsids. The efficient expression of SRLV-rp25 was confirmed by Western blot. The humoral immune responses in mice showed an increased level of antibodies from day 21 to 35 of the SRLV-rp25-GAL and SRLV-rp25-ISCOM® groups and the cellular immune response showed no significant difference in IL-10 levels (P >.05), however, a significant difference (P <.001) was observed when comparing SRLV-rp25-GAL with SRLV-rp25 groups. Immunoreactivity toward SRLV-rp25 revealed 61% of positive samples from naturally infected goats and sheep.

Genetic variability of Haemonchus contortus isolates in small ruminants from slaughterhouses in Bangladesh.

Haemonchus contortus is a blood-sucking gastrointestinal nematode that infects all ruminants and causes significant economic losses in production. Characterizing the genetic variability of H. contortus populations is crucial for understanding patterns of disease transmission and developing effective control strategies against haemonchosis. This study aimed to identify the genetic variability of H. contortus isolates in small ruminants from slaughterhouses in Bangladesh. During January to December 2015, 400 abomasa samples were collected and 186 were found to be positive for Haemonchus. A 321-bp fragment of the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA and an 800-bp fragment of the mitochondrial nicotinamide dehydrogenase subunit-4 gene (nad4) were amplified using polymerase chain reaction (PCR) and directly sequenced. The results showed 10 genotypes (ITS-2) and 45 haplotypes (nad4) among the 186 worms. The sequences were 98.5 to 100% identical to reference sequences from the GenBank database. ITS-2 sequence analysis revealed four nucleotide substitutions at positions 30, 41, 42, and 216. There was one transition (C/T) at position 42 and three transversions (C/A at position 30, G/C at position 41, and T/A at position 216). The nad4 gene sequences showed 15 substitutions, all of which were transitions. The pairwise distance of ITS-2 between H. contortus populations ranged from 0.005 to 1.477. The nucleotide diversity (µ) among the populations was 0.009524 using ITS-2 and 0.00394 using nad4. This study indicated low genetic deviation among H. contortus populations in Bangladesh.

A meta-analysis of the genetic contribution to greenhouse gas emission in sheep.

The objective of this study was to use a random-effects model of meta-analysis to merge various heritability estimates of different gas emission traits (methane yield [METY], methane production [METP], carbon dioxide production [CO2 ], the sum of carbon dioxide and methane production [METP + CO2 ], METP METP + CO 2 ratio, and oxygen consumption [O2 ]) and their genetic association with growth and partial efficiency traits in sheep. A total of 53 genetic correlations and 47 heritability estimates from 13 scientific articles were used in the meta-analysis. The included papers were published between 2010 and 2022. To measure heterogeneity, Chi-square (Q) test was performed, and the I2 statistic was determined. The average heritability estimates for the studied traits were low to moderate and ranged from 0.137 (for METY) to 0.250 (for METP + CO2 ). The heterogeneity test of heritability estimates indicated that heritability estimates for METY, O2 consumption, and METP METP + CO 2 had low Q values and non-significant heterogeneity (p > 0.10). However, the average heritability estimates for other traits experienced significant heterogeneities (p < 0.10). The genetic correlation estimate between METP with O2 was -0.597 (p < 0.05), but its genetic correlations with other gas traits ranged from 0.593 (with METP + CO2 ) to 0.653 (CO2 ; p < 0.05). Also, mean estimates of genetic correlation between METP with live weight (LW), feed intake (FI), and residual feed intake (RFI) were 0.719, 0.598, and 0.408, respectively. The genetic correlations of CO2 with performance traits varied from 0.641 (with RFI) to 0.833 (with FI; p < 0.05). This meta-analysis showed gas emission traits in sheep are under low-to-moderate genetic control. The average genetic parameter estimates obtained in this study could be considered in the genetic selection programmes for sheep, especially when there is no access to accurate phenotypic records or genetic parameter estimates for gas emission traits.

Productive, thermoregulatory, and hormonal responses of dairy goats supplemented with selenium-enriched yeast in the Brazilian semi-arid region.

The aim of this study was to evaluate the effect of adding selenium-enriched yeast (SE) in the diet of dairy goats during 60 days of lactation and its effect on productive, thermoregulatory, and hormonal responses of animals managed in a semi-arid region. Sixteen Saanen × Toggenburg crossbred goats were used in a completely randomized design. Goats were weighed, and their milk yield was monitored weekly. Before the animals entered the treatments and at every 20-day milk producing, blood samples were collected to determine the SE levels. At 20, 40, and days of the lactation cycle, individual milk samples were collected to determine composition, casein, urea nitrogen, and selenium content. Measurements of respiratory rate (RR), rectal temperature (RT), coat surface temperature (CST), and epidermal temperature (ET) were performed weekly during the experimental period in two shifts, one in the morning (9 am) and the other in the afternoon (3 pm). No difference (P > 0.05) was detected for body weight, milk yield, composition, selenium concentration, and urea nitrogen. Lower RR and ET (P < 0.05) were observed for animals that received SE supplementation. Thyroid hormone concentrations were similar between treatments (P > 0.05). The positive results of the SE supplementation were concentrated in thermoregulatory responses, and there was no effect on productive, hormonal responses, and plasmatic concentration of selenium in the milk. The SE supplementation for dairy goats managed in a Brazilian semi-arid region was able to promote reduction of RR and coat temperatures.

Sheep and goat response to Trichostrongylus colubriformis infection based on egg output and worm burden.

This study was aimed to assess the performance of Trichostrongylus colubriformis and the host's responses to regulate egg outputs and worm burden. Infective larva (L3) was prepared by culturing egg of the worms harvested from the intestine of slaughtered sheep. Following this, L3 was maintained in the donor sheep to get adequate quantity of it for experimental trials. A complete randomized block design was used by considering host as blocking factor. Twenty eight small ruminants (sheep = 14) and (goat = 14) were employed in such a way that half of them were drenched with 10,000 T. colubriformis L3 and the remaining halves were controls. Faecal egg count (FEC) was recorded from the initial period (day-zero) up to day-56. At the end of experiment, animals were euthanized in humane manner, worms were recovered from the intestines, counted, and burden was estimated. FEC at various days post infection was insignificantly (P > 0.05) higher in goats than in sheep. The worm burden was significantly (P = 0.040) higher in infected goat than in infected sheep despite they were given equal dose of L3. In conclusion, relatively lower worm burden under natural conditions in goat may be due to their feeding behavior rather than their inherent resistance.

Species identification by MALDI-TOF MS and gap PCR-RFLP of non-aureus Staphylococcus, Mammaliicoccus, and Streptococcus spp. associated with sheep and goat mastitis.

Staphylococci and streptococci are common causes of intramammary infection in small ruminants, and reliable species identification is crucial for understanding epidemiology and impact on animal health and welfare. We applied MALDI-TOF MS and gap PCR-RFLP to 204 non-aureus staphylococci (NAS) and mammaliicocci (NASM) and to 57 streptococci isolated from the milk of sheep and goats with mastitis. The top identified NAS was Staphylococcus epidermidis (28.9%) followed by Staph. chromogenes (27.9%), haemolyticus (15.7%), caprae, and simulans (6.4% each), according to both methods (agreement rate, AR, 100%). By MALDI-TOF MS, 13.2% were Staph. microti (2.9%), xylosus (2.0%), equorum, petrasii and warneri (1.5% each), Staph. sciuri (now Mammaliicoccus sciuri, 1.0%), arlettae, capitis, cohnii, lentus (now M. lentus), pseudintermedius, succinus (0.5% each), and 3 isolates (1.5%) were not identified. PCR-RFLP showed 100% AR for Staph. equorum, warneri, arlettae, capitis, and pseudintermedius, 50% for Staph. xylosus, and 0% for the remaining NASM. The top identified streptococcus was Streptococcus uberis (89.5%), followed by Strep. dysgalactiae and parauberis (3.5% each) and by Strep. gallolyticus (1.8%) according to both methods (AR 100%). Only one isolate was identified as a different species by MALDI-TOF MS and PCR-RFLP. In conclusion, MALDI-TOF MS and PCR-RFLP showed a high level of agreement in the identification of the most prevalent NAS and streptococci causing small ruminant mastitis. Therefore, gap PCR-RFLP can represent a good identification alternative when MALDI-TOF MS is not available. Nevertheless, some issues remain for Staph. haemolyticus, minor NAS species including Staph. microti, and species of the novel genus Mammaliicoccus.

Infestation rates, seasonal distribution, and genetic diversity of ixodid ticks from livestock of various origins in two markets of Yaoundé, Cameroon.

Little is known about the impact of ticks on livestock and humans in Cameroon. This study aimed to determine the prevalence, seasonal variation, and genetic diversity of hard ticks in the country. Ticks were collected during a cross-sectional survey on domestic livestock in two markets of Yaoundé in 2019 and 2020 and identified using morphological keys, 16S ribosomal DNA, (16S rDNA), and the cytochrome c oxidase subunit 1 (Cox1) genes. The infestation rates were 39.18%, 11.53%, and 2.74% in cattle, sheep, and goats respectively. Three genera of ticks were identified, Rhipicephalus, Amblyomma, and Hyalomma comprising eleven tick species. The main species were Rhipicephalus decoloratus (30.25%), R. microplus (24.43%), and Amblyomma variegatum (12.96%). Rhipicephalus spp. (81.31%) and Amblyomma variegatum (51.54%) were abundant during the rainy season, while Hyalomma spp. (83.86%) during the dry season (p-value <0.00001). Cox1 and 16S rDNA analysis showed a high level of genetic diversity among tick species with sequences close to those observed across Africa. Phylogenetic analysis revealed that our R. microplus belong to clade A and we identified R. sanguineus s.l. as R. linnea. This study shows a high tick infestation rate in cattle, while low in small ruminants with an extensive diversity of tick species, including several known vectors of important tick-borne diseases.

Consumer attitudes toward dairy products from sheep and goats: A cross-continental perspective.

This study aimed to assess consumer knowledge, attitudes, and perceptions toward dairy products from sheep and goats. A web-based survey was conducted in Latin America (Mexico and Chile), Europe (Italy, Spain, Greece, and Denmark), and Asia (Bangladesh). From March to June 2021, adult participants answered an online survey available in 5 languages. In total, 1,879 surveys were completed. Categorical and ordinal data were analyzed as frequencies and percentages. To determine the relationship between the variables for purchasing and consumption behaviors of respondents who declared that they consume dairy products, a multiple correspondence analysis was carried out. Most completed surveys were from Mexico and Italy (30% and 33.7%, respectively). Most respondents were between 18 and 29 yr old, female, highly educated, and employed. The majority of respondents (70.8%) declared that they consume dairy products from small ruminants. Consumers preferred products from both sheep and goats (49.4%); however, it was observed that in Mexico, Denmark, and Bangladesh, more than 50% preferred goat dairy products. The most-consumed products were mature and fresh cheeses. Mature cheese was the most-preferred product in Chile; in Mexico, Italy, Greece, and Denmark, it was fresh cheese. Unlike the rest of the countries, in Bangladesh, dairy product consumption from small ruminants was observed by more than 30% of respondents. In Mexico, a higher percentage of people do not consume sheep or goat dairy products because they are unfamiliar with them. In Mexico, Chile, and Bangladesh, limited market availability was also a variable responsible for nonconsumption. In European and Asian countries, sheep and goat dairy products are not consumed because consumers dislike them, in addition to a greater awareness of sustainability and climate change issues. The multiple correspondence analysis defined 5 dimensions. Dimension 1 was associated with the geographic location of the respondent (country and continent), the type of milk (sheep or goat), and the consideration of well-being and health as characteristics associated with the consumption of dairy products from small ruminants. Dimension 2 was associated with the respondent's country of origin and the frequency of consumption. Dimension 3 was associated with gender, education, and employment status. Dimension 4 was associated with the respondent's age, the association of the "healthy" concept of sheep and goat dairy products, and the consideration of the nutritional benefits of dairy as responsible for considering them healthy. Dimension 5 was associated with a "strong smell and taste" of sheep and goat dairy products. This study showed that consumer attitudes toward dairy products from sheep and goats vary between continents. In conclusion, results showed consumer interest in animal welfare and environmental impact issues related to small ruminant farming as well as a general attraction to local products. It seems that these factors contribute to consumers' perception of the quality of dairy products, so the industry and select farmers should carefully consider incorporating them into their supply chain.

Nutrient intake, digestibility, feeding behavior, nitrogen balance, and performance of feedlot goat kids fed high-concentrate diets containing licury cake (Syagrus coronata).

The current trial was carried out to evaluate the impacts of adding licury cake (Syagrus coronata) in high-concentrate diets for goat kids feedlot-finished on growth performance and metabolic parameters. Forty crossbred non-castrated Boer goat kids with approximately four months and similar initial live weights (20.15 ± 2.79 kg). The experimental design used in this study was a completely randomized, with four diets (0, 10, 20, and 30% of licury cake inclusion in a dry matter basis (DM)). Licury cake inclusion decreased nutrient intake and digestibility (P < 0.05). Times spent in feeding (P < 0.001) and rumination (P = 0.003) activities, number of events in feeding (P < 0.001) and idling (P = 0.015) increased, whereas a linear reduction occurred in feeding and rumination efficiencies of DM and neutral detergent fiber (P < 0.001). Nitrogen (N) intake, retained N (P < 0.001), triglycerides concentrations (P = 0.002), aspartate-aminotransferase, alanine-aminotransferase, and gamma-glutamyltransferase decreased with the licury cake inclusion (P < 0.05). Final body weight (P = 0.008), average daily gain (P = 0.001), and total weight gain (P = 0.001) decreased linearly when licury cake was included in diets. High-concentrate diets containing increasing levels of licury cake decrease intake and apparent digestibility of nutrients and performance when supplied for goat kids feedlot-finished. Therefore, the inclusion of the studied levels of licury cake in goat kids fed high-concentrate diets is not recommended for feedlot-finished systems.

Replication of Small Ruminant Lentiviruses in Aluminum Hydroxide-Induced Granulomas in Sheep: a Potential New Factor for Viral Dissemination.

Aluminum (Al)-based salts are widely used adjuvants in ruminants and other species to strengthen the immune response elicited against vaccine antigen(s). However, they can lead to the formation of long-lasting granulomas composed of abundant activated macrophages. Small ruminant lentiviruses (SRLV) are widely distributed macrophage-tropic retroviruses that cause persistent infections in sheep and goats. Infected monocytes/macrophages and dendritic cells establish an inflammatory microenvironment that eventually leads to clinical manifestations. The aim of this work was to study the effect of Al-induced granulomas in the replication and pathogenesis of SRLV. Eleven adult, naturally SRLV-infected sheep showing clinical arthritis were distributed in vaccine (n = 6), adjuvant-only (n = 3), and control (n = 2) groups and inoculated with commercial Al-based vaccines, Al hydroxide adjuvant alone, or phosphate-buffered saline, respectively. In vitro studies demonstrated viral replication in Al-induced granulomas in 5 out of 10 sheep. Immunohistochemistry (IHC) evinced granular, intracytoplasmic SRLV presence in macrophages within granulomas. Viral sequences obtained from granulomas, blood monocytes, and other tissues were highly similar in most animals, suggesting virus circulation among body compartments. However, notable differences between isolated strains in granulomas and other tissues in specific animals were also noted. Interestingly, the B2 subtype was the most commonly found SRLV genotype, reaching a wider body distribution than previously described. Recombination events between genotypes B2 and A3 along the gag region were identified in two sheep. Our results indicate that Al-hydroxide-derived granulomas may represent an ideal compartment for SRLV replication, perhaps altering natural SRLV infection by providing a new, suitable target tissue.IMPORTANCE Granulomas are inflammation-derived structures elicited by foreign bodies or certain infections. Aluminum adjuvants included in vaccines induce granulomas in many species. In sheep, these are persistent and consist of activated macrophages. Small ruminant lentiviruses (SRLV), which are macrophage-tropic lentiviruses, cause a chronic wasting disease affecting animal welfare and production. Here, we studied the occurrence of SRLV in postvaccination granulomas retrieved from naturally infected ewes after vaccination or inoculation with aluminum only. SRLV infection was confirmed in granulomas by identification of viral proteins, genomic fragments, and enzymatic activity. The infecting SRLV strain, previously found exclusively in carpal joints, reached the central nervous system, suggesting that occurrence of SRLV in postvaccination granulomas may broaden tissue tropism. SRLV recombination was detected in inoculated animals, a rare event in sheep lentiviruses. Potentially, virus-host interactions within granulomas may modify viral pathogenesis and lead to more widespread infection.

Vaccines for caseous lymphadenitis: up-to-date and forward-looking strategies.

Caseous lymphadenitis (CLA) is an infectious chronic disease responsible for economic losses in sheep and goat breeding worldwide. CLA has no effective treatment, evidencing the vaccination schedule as the best control strategy. Although some commercial vaccines have been available, none of them provides total protection, which is sometimes insufficient and does not reach the same efficiency when compared in sheep and goats. They also have questionable safety levels and side effects. In light of this, several experimental vaccines are in development in order to improve safety, reproducibility, and protective immune response against the etiologic agent of CLA, Corynebacterium pseudotuberculosis. In this review, we discussed aspects as antigen, adjuvant, routes of administration, protection level, and animal models used in CLA vaccine development, as well the challenges and future perspectives. KEY POINTS: Caseous lymphadenitis (CLA) does not have an appropriate commercial vaccine. Different experimental vaccines are in development aiming to protect against Corynebacterium pseudotuberculosis. An ideal vaccine for CLA is necessary for the disease control.

Species-Specific Humoral Immune Responses in Sheep and Goats upon Small Ruminant Lentivirus Infections Inversely Correlate with Protection against Virus Replication and Pathological Lesions.

Maedi-Visna-like genotype A strains and Caprine arthritis encephaltis-like genotype B strains are small ruminant lentiviruses (SRLV) which, for incompletely understood reasons, appear to be more virulent in sheep and goats, respectively. A 9-month in vivo infection experiment using Belgian genotype A and B SRLV strains showed that almost all homologous (genotype A in sheep; genotype B in goats) and heterologous (genotype A in goats; genotype B in sheep) intratracheal inoculations resulted in productive infection. No differences in viremia and time to seroconversion were observed between homologous and heterologous infections. Higher viral loads and more severe lesions in the mammary gland and lung were however detected at 9 months post homologous compared to heterologous infection which coincided with strongly increased IFN-γ mRNA expression levels upon homologous infection. Pepscan analysis revealed a strong antibody response against immune-dominant regions of the capsid and surface proteins upon homologous infection, which was absent after heterologous infection. These results inversely correlated with protection against virus replication in target organs and observed histopathological lesions, and thus require an in-depth evaluation of a potential role of antibody dependent enhancement in SRLV infection. Finally, no horizontal intra- and cross-species SRLV transmission to contact animals was detected.

Outbreak of Peste des Petits Ruminants among Critically Endangered Mongolian Saiga and Other Wild Ungulates, Mongolia, 2016-2017.

The 2016-2017 introduction of peste des petits ruminants virus (PPRV) into livestock in Mongolia was followed by mass mortality of the critically endangered Mongolian saiga antelope and other rare wild ungulates. To assess the nature and population effects of this outbreak among wild ungulates, we collected clinical, histopathologic, epidemiologic, and ecological evidence. Molecular characterization confirmed that the causative agent was PPRV lineage IV. The spatiotemporal patterns of cases among wildlife were similar to those among livestock affected by the PPRV outbreak, suggesting spillover of virus from livestock at multiple locations and time points and subsequent spread among wild ungulates. Estimates of saiga abundance suggested a population decline of 80%, raising substantial concerns for the species' survival. Consideration of the entire ungulate community (wild and domestic) is essential for elucidating the epidemiology of PPRV in Mongolia, addressing the threats to wild ungulate conservation, and achieving global PPRV eradication.

A highly sensitive semi-nested real-time PCR utilizing oligospermine-conjugated degenerate primers for the detection of diverse strains of small ruminant lentiviruses.

Small ruminant lentiviruses (SRLVs) are highly diverse retroviruses infecting sheep and goats. Although PCR-based testing is being utilized for diagnostics, its application is hampered by various factors. These include, among others, the exceptionally high genetic variability of SRLVs, as well as the low number of infected blood monocytes. For this reason, a highly sensitive and specific semi-nested real-time PCR for proviral DNA detection and quantification was developed. The method is innovative in that a) its design is based on selecting the preferred codon usage in the targeted conserved genomic regions and b) oligospermine-conjugated degenerate primers with increased Tm were utilized. Modifications permitted primer/template duplex formation in the cases of mismatches due to sporadic nucleotide polymorphisms in a number of variant SRLV strains and consequently, the detection of highly diverse SRLV strains. The potential loss of analytical sensitivity and specificity was counterbalanced by including a semi-nested step in combination with LNA probes. An in silico procedure for the evaluation of hybridization efficiency of the designed oligonucleotides to all known targeted variants was also implemented. The method presents a linear range of quantification over a 3-log10 range and a limit of detection of 3.9 proviral dsDNA copies per reaction. Its diagnostic performance was evaluated by testing field samples from seropositive and seronegative animals, followed by phylogenetic analysis of the strains detected. To further increase the diagnostic sensitivity, a DNA extraction protocol for blood leukocytes was developed and evaluated. A minimum of 500 ng input DNA is recommended for PCR-based detection of SRLV proviral DNA, given the low numbers of infected blood monocytes. The developed methodology may serve as a useful tool, which can be adjusted for the quantitative detection of viruses exhibiting high genetic variability.

Molecular detection of small ruminant piroplasmosis and first report of Theileria luwenshuni (Apicomplexa: Theileridae) in small ruminants of Pakistan.

Theileriosis is a widespread and economically important disease of small ruminants in Pakistan. Ruminants are the intermediate hosts in the lifecycle of Theileria spp., with ticks of the family Ixodidae being the definitive hosts. To better understand the distribution and prevalence of theileriosis in Pakistan, a molecular survey was performed in small ruminants from the Lower Dir district of the Khyber Pakhtunkhwa province. A total of 200 healthy sheep and goats were screened from Maidan, Samar Bagh and Munda districts of district Dir Lower, Pakistan during December (2017) to April (2018). DNA samples were screened through nested PCR using universal primers. The amplified 492-498 bp amplicon was subjected to RLB analysis which was based on the hypervariable of the 18S rRNA gene to test for the presence of genotypes of Theileria in blood samples. A phylogeny was constructed to determine the species of Theileria genotypes. Nested PCR results indicated 53.5% prevalence of one or more Theileria genotypes in the blood of the host animal. From RLB assay, 27 animals (13.5%) showed infection with only a single species of Theileria while 80 animals (40%) showed coinfection by multiple Theileria spp. Based on the 18S rRNA phylogeny, the unknown genotype is of the species Theileria luwenshuni and is closely related to Chinese isolates. The present finding is the first report on molecular diagnosis of Theileria luwenshuni in small ruminants in Pakistan.