Search Results (106)

In remote alpaca breeding regions, access to advanced sperm analysis laboratories is limited. This study validates a practical cytometric method for evaluating sperm viability and acrosomal integrity in epididymal alpaca sperm using early fluorochrome staining, formaldehyde fixation, and intermediate storage. Thirty-two testes were transported at 5 °C, and spermatozoa were collected from the cauda epididymis. After morphometric screening, 26 samples were included. Aliquots were stained with Zombie Green (viability) and FITC–PSA (acrosomal integrity), at time zero. Each aliquot was divided for cytometric analysis at T0 (immediately), T24 (24 h after formaldehyde fixation) and T1w (1 week post-fixation). Fixed samples showed higher viability and acrosomal integrity values (T24: 70.75%, 97.24%; T1w: 71.80%, 97.21%) than T0 (67.63%, 95.89%). This may reflect fluorescence alterations associated with fixation. Strong correlations and Bland–Altman analysis confirmed consistency across time points. This method enables accurate sperm quality evaluation up to one week after collection, offering a useful tool for reproductive monitoring in field conditions without immediate analysis. Further research on ejaculated semen and field protocols is recommended. Full article

A single domain antibody (SDAb) targeting canine PD-1 was developed as a potential immunotherapeutic for canine cancer. An alpaca was immunized with canine PD-1 protein, and a phage-display library was constructed using mRNA isolated from peripheral lymphocytes. Screening of the library yielded multiple SDAb candidates capable of nanomolar binding to canine PD-1. Among these, clone STX-1b5 demonstrated high expression in a yeast-based recombinant system and was selected for further characterization. Binding and competition assays using ELISA confirmed its ability to bind canine PD-1 and block PDL-1 interaction. In silico structural modeling supported the interaction of STX-1b5 with key PD-1 residues implicated in ligand binding. These findings support the feasibility of using SDAbs and cost-effective yeast expression systems to generate immunotherapeutics for veterinary use, with STX-1b5 representing a promising lead candidate for future clinical development. Full article

Diarrhea in alpaca crias significantly impacts livestock health in high-altitude regions, with Escherichia coli as a common pathogen. This study analyzed 10 E. coli isolates from diarrheic and healthy alpacas using whole-genome sequencing to assess genetic diversity, virulence factors, and antibiotic resistance. Predominant sequence types (ST73, ST29), serotypes (O22:H1, O109:H11), and phylogroups (B2, B1, A) were identified. Virulence profiling revealed ExPEC-like and EPEC pathotypes, while resistance genes for β-lactams (blaEC-15), fosfomycin (glpT_E448K), and colistin (pmrB) were prevalent. These findings highlight the need for genomic surveillance and antimicrobial stewardship to manage E. coli infections in alpacas and reduce public health risks. Full article

As part of an implementation in the Peruvian textile industry, the use of different sources to obtain blue hues in alpaca fiber has taken on a prominent role. The present study investigated the optimization of the dyeing process of alpaca fibers using indigo carmine as dye. The methodology was based on a central composite design (CCD) and response surface methodology (RSM) with color strength (K/S) as response variable. The results demonstrate that the independent variables significantly affected the color strength (K/S). In this context, an increase in both mordant concentration (3.9887 g/L) and dyeing temperature (95 °C), coupled with lower exhaust time (30.0019 min), enhanced levels of superficial dye adsorption. Additionally, color fastness properties provided tolerable values according to the gray scale. In conclusion, the optimization of the dyeing process of alpaca fibers using indigo carmine enabled the achievement of a blue shade with satisfactory fastness properties in the fiber yarns. Full article

This study aimed to perform ultrasonography of the tympanic bulla in healthy, non-sedated camelids for the first time. In the first step, dissection and sonography in cadaver specimens allowed the essential identification of the anatomical structures of the region of interest. Ultrasonography of the tympanic bulla was then performed on 71 healthy llamas and alpacas, and the length of the visible lateral bulla wall was measured sonographically. The reproducibility of measuring was determined between two examiners. Differences in length and the influences of gender, age, and body condition scores were monitored. A 10 MHz linear probe was positioned in the rostrocaudal and dorsoventral directions caudal to the mandibular ramus and ventral to the base of the ear using a lateral approach. The equipment used proved to be appropriate to visualize the tympanic bulla, the zygomatic bone, the paracondylar process, the external ear canal, and the parotid gland in the cadaver specimens and all live animals. Llamas revealed a significantly longer visible lateral bulla wall than alpacas, but its length was not influenced by gender, body condition score, or age. In alpacas, older females showed a significantly shorter tympanic bulla wall. The intra- and inter-observer reliability yielded a significant agreement. Based on this study’s results, ultrasonography may serve as a non-invasive diagnostic tool for detecting osseous and soft-tissue changes in camelids with otitis media. Full article

There is limited investigation of the alpaca microbiome on a global scale, with no previous research conducted in Australia characterising the faecal microbiome. The microbiome composition in other ruminants has been shown to impact feed efficiency, average daily gain and methane production. This study aimed to characterise the faecal microbiome of alpacas raised in south-eastern Australia and identify variation across geographic regions. Faecal samples were collected from 59 healthy adult female alpacas, aged between 15 months and 17 years in NSW, Australia. Firmicutes were identified as the dominant phyla, accounting for 57.78% of the cumulative abundance, followed by Bacteroidota (29.12%). These two phyla accounted for 90% of the taxa, with the cumulative abundance of Firmicutes and Bacteriodota significantly differing (p < 0.05) across locations. There was no effect of age on the frequency of microbes identified at either phyla or class levels. The alpaca’s production status only significantly affected the abundance of Firmicutes Clostridia Oscillospirales (p = 0.0026). The breakdown of the alpaca faecal microbiome identified here is consistent with previous ruminant and camelid studies. This study provides a valuable baseline for the microbiome characterisation of alpacas in south-eastern Australia and can be used as a baseline for further microbiome studies. Full article

This study evaluated the genetic diversity and population structure of Vicugna pacos (Huacaya alpacas) from two contrasting breeding contexts in Junín, Peru: the genetically managed herd of INIA’s Santa Ana Experimental Station (Suitucancha) and the community-based herd of Huayre, where natural, unregulated mating practices are common. An external reference population from Quimsachata was also included. Genetic diversity parameters revealed high allelic richness and heterozygosity within all populations. Analyses of molecular variance (AMOVA), principal coordinate analysis (PCoA), Bayesian clustering, and phylogenetic reconstruction indicated moderate genetic differentiation between Suitucancha and Huayre, likely influenced by the use of selected males under controlled mating in Suitucancha versus natural, unregulated group mating in Huayre, which facilitates broader gene flow. The Quimsachata group displayed distinct genetic characteristics, likely reflecting limited gene flow due to its role as a germplasm conservation nucleus under closed reproductive management. These results reflect how differences in reproductive management may influence population structure in alpacas. Full article

Mycobacterium is one of the most dangerous pathogens of both animals and humans. Bovine tuberculosis (BTB) is a disease caused by mycobacteria belonging to the Mycobacterium tuberculosis complex (MTBC), which spreads mainly among domestic cattle but also to mammals other than cattle. The transmission of MTBC between different species requires research and epidemiological investigations to control its spread. When multiple species are a reservoir of infection, it poses a significant public health and veterinary concern. In this study, the diagnosis of alpaca, cattle, horses, dogs, a sheep and a cat from one farm suspected of bovine tuberculosis was performed. The animals (except for one horse, the dogs and the cat) were euthanised after the intradermal tuberculin tests. Mycobacterial isolation from animal tissue samples was performed. The obtained Mycobacterium strains were genotyped using spoligotyping and mycobacterial interspersed repetitive unit–variable number tandem repeat (MIRU-VNTR) methods. The isolates from a horse, two cows, a sheep and an alpaca were classified as Mycobacterium (M.) bovis. The single M. bovis spoligotype SB0666 pattern was isolated, and the MIRU-VNTR results presented the same 222632237401435 patterns. The molecular investigation uncovered information on the relationship of Mycobacterium bovis. Full article

The Chikungunya virus (CHIKV) is a priority endemic pathogen identified by the World Health Organization and its infection induces an acute febrile illness in humans that is often associated with arthritis and musculoskeletal pain. Therefore, specific vaccines and treatments are urgently needed to prevent or treat Chikungunya disease. Here, we identify a series of CHIKV-specific neutralizing nanobodies (Nbs) from an alpaca which exhibit distinct binding modes compared to those previously reported. Two representative anti-CHIKV Nbs, N033-Fc and N053-Fc, demonstrated significant antiviral activity in Ifnar^−/− mice against lethal challenge. Further studies elucidated the functional mechanisms of N033-Fc and N053-Fc in blocking CHIKV infection at multiple stages of the viral life cycle. This study identifies multiple candidate Nbs that may be suitable for next-generation antibody therapies to combat CHIKV infection. Full article

Rift Valley fever virus (RVFV) is a mosquito-transmitted bunyavirus that can cause substantial morbidity and mortality in livestock and humans, for which there are no currently available licensed human therapeutics or vaccines. Therefore, the development of safe and effective antivirals is both necessary and urgent. The Gc protein is the primary target of the neutralizing antibody response related to Rift Valley fever virus. Here, we report one Gc-specific neutralizing antibody (NA137) isolated from an alpaca and one bispecific antibody (E2-NA137), the protective efficacies of which we evaluated in A129 mice. In this prophylactic study, the survival rates of the NA137 and E2-NA137 groups were both 80%, and in the treatment study, the survival rates were 20% and 60%, respectively. Altogether, our results emphasize that NA137 and E2-NA137 provide a potential approach for treating RVFV either prophylactically or therapeutically. Full article

Understanding maternal behaviour is essential for good animal husbandry; yet, little scientific information currently exists regarding nursing behaviour of alpacas (Vicugna pacos). Moreover, allonursing (the nursing of non-filial offspring) has only been documented in captive non-domesticated guanacos. This study aimed to (1) describe the nursing behaviour of alpacas within traditional husbandry systems in their place of origin, and in foreign conditions, and to (2) investigate the occurrence of allonursing in alpacas. A total of 1899 nursing bouts were observed in the Andes and Central Europe. Additionally, 102 Andean farmers were asked if they observed allonursing in their herds. Nursing behaviour was similar at both locations, with most of the nursing bouts initiated by crias and terminated by dams. However, several significant differences between localities were noted, such as the less frequent sniffing of crias by Andean dams. Crias’ age and sex did not affect the percentage of nursing bouts initiated or terminated by the dams. Rare cases of allonursing were recorded in Central Europe (n = 5), and 18.6% of surveyed Andean farmers reported allonursing in their herds. This study provides insight into alpaca nursing and allonursing behaviour, which may contribute towards their management both in their place of origin and farther. Full article

The aim of the study was to determine the extent and intensity of gastrointestinal parasite infections in alpacas (Vicugna pacos) in Poland, considering factors such as region, gender, age, and season. The research was conducted on 29 herds located throughout Poland. Faecal samples from 512 alpacas were collected in autumn 2023 and spring 2024. Examination was performed using the direct flotation and McMaster methods. The average prevalence of gastrointestinal parasitic infections was 74.4%; 68.8% of alpacas were infected with nematodes and 34.8% with protists of the genus Eimeria. The most commonly detected parasites were Nematodirus spp. (38.5%) and Eimeria punoensis (18.2%). The analysis revealed significant differences in the intensity of gastrointestinal parasitic infections depending on region, age, gender, and season, suggesting the need to tailor deworming programs to the specific requirements of different groups of alpacas. Furthermore, regional differences in the prevalence of Strongyloides sp. and Strongylida infections were observed, indicating a significant impact of local environmental conditions and husbandry practices on the risk of infection. Seasonal variations in the intensity of Eimeria infections, particularly in autumn, were also noted. Parasitic infections in alpacas in Poland are common and generally asymptomatic. These results highlight the need for the implementation of a comprehensive preventive program for controlling parasitic infection, including regular diagnostics, pasture management optimization, maintenance of hygiene, and selective use of antiparasitic drugs in alpacas. Full article

Background/Objectives: Doxycycline, a tetracycline-class antibiotic, is commonly used across various species to treat infections caused by susceptible bacteria. However, pharmacokinetic data on its use in alpacas remains limited. This study aimed to investigate the pharmacokinetics of doxycycline following intravenous (IV) and subcutaneous (SC) administration in alpacas. Methods: A randomized crossover study (n = 6) was employed, with dosages of 5 mg/kg and 20 mg/kg after intravenous and subcutaneous administration, respectively. Blood samples were collected at predetermined times up to 96 h after both routes of administration. Plasma doxycycline concentrations were determined using validated high-performance liquid chromatography with a UV detector and then analyzed based on non-compartmental pharmacokinetic methods. Results: All alpacas maintained optimal health and general condition throughout the trial period. After intravenous administration, the V_z value (0.90 L/kg) indicated a good distribution of this antibiotic in the alpacas. The maximum concentration value (C_max) after SC administration of doxycycline was 1.40 µg/mL, reached at 1.92 h. Low bioavailability (F = 36.83%) of doxycycline was observed after SC administration. Conclusions: PK/PD ratios calculated from the pharmacokinetic data obtained, at a dose of 20 mg/kg and SC route of administration, suggest that doxycycline administered every 24 h could be effective against bacterial infections with MICs of 0.125 and 0.5 µg/mL. However, multi-dose and pharmacodynamic studies are needed to further evaluate the efficacy of using doxycycline in alpacas. Full article

Zearalenone (ZEN), a toxic estrogenic mycotoxin in cereals, threatens human and animal health through reproductive, immune, and cytotoxic effects, necessitating sensitive detection methods. While nanobodies offer advantages over conventional antibodies for on-site ZEN detection, their application remains unexplored. This study aimed to develop an anti-ZEN nanobody derived from an anti-ZEN phage display nanobody library. An alpaca was immunized with a ZEN-bovine serum albumin (ZEN-BSA) antigen, achieving peak serum antibody titers (1:25,600) following four immunizations. A high-capacity phage display nanobody library (1.0 × 10¹¹ plaque-forming units/mL) was constructed. Following four rounds of biopanning, an enrichment factor of 479 was achieved. Phage ELISA screening identified six phage display nanobodies with specific ZEN-binding activity, and multiple sequence alignment revealed four unique nanobody sequences. The selected phage display nanobody, designated phage-V44, was expressed and purified, and its presence was validated by SDS-PAGE and western blotting, which detected a single approximately 17 kDa band consistent with the expected nanobody size. We established a working curve for an indirect competitive enzyme-linked immunoassay (ELISA) for ZEN, which showed an IC50 value of 7.55 ng/mL. The specificity and affinity of the V44 were also verified. Collectively, the study successfully constructed an anti-ZEN phage display nanobody library, screened four specific ZEN-binding phage display nanobodies, and prepared the anti-ZEN nanobody V44. Thereby establishing a foundation for the nanobody’s future integration into rapid on-site detection methods for ZEN in both animal feed and human food products. Full article