Disease Of Sheep Research Articles

Investigation of the Occurrence of Lungworm Pneumonia in Sheep Based on Histopathological Study in Tehran Province

Lung parasites are one of the main causes of respiratory diseases in sheep in most parts of the world. The survival and development of lung parasites in sheep occurs more in tropical and subtropical regions of the world and this leads to the removal of this organ, which includes many economic losses. In this study, the lungs of 4500 sheep from various farms in an industrial slaughterhouse in Tehran province were examined. After slaughter, common methods of meat inspection were used to identify pathological lesions in carcasses using macroscopic examinations. As a result, macroscopic pneumonia was identified in the lungs of 420 sheep (9.33%). Then, based on specific features such as the presence of gray-white nodules, brown spots, and the presence of adult worms, 65 lungs suspected of lungworm pneumonia were identified and tissue samples were taken.

Prevalence of Haemonchosis in Slaughtered Sheep in Daronta, Nangarhar

Background: In developing countries, one of the most prevalent parasitic diseases is Haemonchosis. This infectious disease mostly caused severe clinical symptoms and ultimately death in small and large-scale ruminants. Materials and Methods: A cross-sectional investigation was carried out to seek the prevalence of Haemonchus spp. in slaughtered sheep at Daronta in various restaurant abattoirs in Nangarhar, Afghanistan. A total of 150 abomasum from slaughtered animals were observed from November 2018 to June 2019. The study animals were grouped based on sex (female and male) and their age (< 1 year, 1 – 2 years, and > 2 years). Findings: The results showed that the overall prevalence of Haemonchosis in sheep was 22.66%. In terms of age, the prevalence rate was higher in a group less than 1 year, (27.27%) followed by 1 to 2 years, (22.44%), and more than 2 years (14%) sheep. The sex-wise prevalence of Haemonchosis was higher in females (30.61%) as compared to males (18.81%). There was no significant difference (P > 0.05) between sex and age groups. Conclusion: The epidemiological evidence of the current study exhibited that Haemonchosis is a noticeably prevalent disease in sheep in Daronta, Nangarhar. To prevent, de-worming and good management practices are recommended.

Histopathological Inspection of the Occurrence of Lung Adenocarcinoma in Sheep in Tehran Province

Sheep pulmonary adenomatosis is a chronic respiratory disease with a long incubation period that many countries have long recognized. This disease is specific to sheep and most prominent in sheep over three years old. The cause of this disease in sheep is Beta Retroviruses (JSRV) which are transmissible among sheep. Since 1342, there have been reports of clinical cases of the disease in different regions of Iran. So far, histopathology has been one of the best diagnostic methods for this disease. The conducted research inspects the occurrence rate and pathological lesions of this disease in a slaughterhouse located in Tehran. All the studied sheep in this research were bred in the livestock farms of Tehran province and referred to the slaughterhouse. During routine inspections, the lungs that showed different macroscopic signs of pneumonia had been primarily identified and recorded; later, more thorough evaluations of macroscopic and microscopic examinations were performed. One hundred sheep lungs, which showed visible lesions of interstitial pneumonia, were selected for histopathological research. These lungs were generally heavy, edematous, had no signs of collapse, showed rib marks on the lung parenchyma, and appeared waterlogged in some cases. The affected areas were firm and light grey in some lungs. OPA histopathological lesions were observed and documented in 25 out of 300 suspicious lung samples. All twenty-five of the damaged lungs were almost similar in histopathological appearance and showed papillary protrusions consisting of short cuboid to columnar cells inside the ducts of alveoli and bronchioles, respectively. In the atypical form of the disease, which included all cases observed in the present study, infiltration of mononuclear cells and connective tissue was more substantial; large and foamy macrophages were also observed in the alveoli and bronchioles that were present in the vicinity of neoplastic lesions. The classical form of OPA, characterized by the infiltration of macrophages and lymphocytes and the formation of neutrophilic and fibrin molds, was observed in any of the cases.

Liver Diseases in Sheep and Goats: Parallel Sonographic and Pathologic Findings

Liver Diseases in Sheep and Goats: Parallel Sonographic and Pathologic Findings

Molecular Detection of Peste des Petits Ruminants Virus (PPRV) in Goats and in Sheep in Ibadan, Oyo State, Nigeria.

Peste des petits ruminants (PPR) is a vaccine-preventable transboundary animal disease of goats and sheep majorly, and is regarded as a major constraint to small ruminant production especially in developing countries like Nigeria. Despite different strategies that have been employed to control PPR in Nigeria, cases of the disease are still reported in PPR-vaccinated and unvaccinated small ruminant farms. In this study, molecular detection of field PPR virus (PPRV) strains was carried out to determine the presence of PPRV. A total of 135 samples (45 oculo-nasal swabs and 90 tissue samples) were purposively collected between August and October 2020 from goats and sheep at the Akinyele live small ruminant market and at Akinyele and Amosun abattoirs in Ibadan, Oyo State, Nigeria. Using reverse transcriptasepolymerase chain reaction with primers targeting the partial N-gene of PPRV, 10 out of the 135 (7.4%) field samples yielded positive results. The results of this study reveal that PPRV currently circulates in Ibadan. These findings underscore the need for continuous PPR surveillance, more extensive characterization of circulating PPRV strains and the importance of consistent use of quality vaccines in the country to achieve more effective preventive and control strategies against the disease.

Evaluation of Resistance and Susceptibility to Prion Diseases in Pelibuey Sheep from Mexico

Abstract Transmissible spongiform encephalopathies (TSEs) are a group of neurodegenerative diseases with a chronic and fatal course, which are caused by a misfolded form of the cellular prion protein that is encoded by the host. The purpose of this work was to evaluate the resistance and genetic susceptibility to prion diseases in Pelibuey sheep from Mexico. The sequences of 99 Pelibuey sheep from the central and southwestern regions of Mexico were analyzed to determine the polymorphisms related to resistance and genetic susceptibility to scrapie, the Hardy-Weinberg equilibrium test and the D-Tajima test was used to identify the effect of evolutionary forces on the PRNP gene. Twelve non-synonymous polymorphisms Q101R, M112T, A116P, G127A, A136V, M137T, L141F, H143R, R154H, Q171R, Q171H, N176K were detected, in addition two synonymous substitutions 231R (agg/cgg) and 237L (ctc/ctg) were found. As a result of the sequence analysis, the ARR allele was not under the Hardy-Weinberg equilibrium, indicating that there is an evolutionary force at work, and the D-Tajima suggest the existence of purifying genetic selection. In conclusion, Pelibuey sheep exhibit genotypes for the PRNP gene that make them resistant to developing classic scrapie; at least 98% of the population is a carrier of an allele related to scrapie resistance; while for atypical scrapie there is a very high probability that an outbreak occurred in the herds, since the ARQ allele in combination with the L substitution at codon 141 confers susceptibility to carrier sheep.

Abortions in Peste Des Petits Ruminants (PPR) infected flocks in Yola North of Adamawa and Askira Uba areas of Borno State, Nigeria

Peste des petits ruminants (PPR) is a highly contagious viral disease of sheep and goats with as high as 90% morbidity and 80% mortality rates. Although, its substantial economic consequences are reported in goats worldwide, there are currently little information regarding abortion cases in PPR endemic areas in Nigeria. This study investigated occurrences of abortion among PPR infected goats in Yola North and Askira Uba local government areas of Adamawa and Borno States respectively. The study involved analysis of clinical case records of two thousand Sahel goats (n = 2000) procured as part of a livestock restocking program by a government agency. The goats were purchased from local markets and held in quarantine for 2 weeks during which PPR infection was monitored. In the study, a fast spreading infection characterized by severe dehydration, respiratory difficulty, pyrexia, depression, anorexia, nasal and ocular discharges and death of many infected goats informed a suspicion of PPR infection. The number of abortions, mortality and age of the animals were recorded during the investigation. Data were organized in a 2×2 contingency table and analyzed using Chi-square. The overall mortality in both populations was 42% and the occurrence of abortion was 1% and 3% in Yola North and Askira Uba holding sites respectively. The proportion of abortions did not differ significantly (p > 0.05) between both populations but there was a positive association indicated as r = 0.4264 and 0.4638 between the occurrence of abortion and mortality in Yola North and Askira Uba holding sites respectively. In addition, the severity in clinical manifestation of the disease appeared higher in younger goats (< 1 years) than the adult ones. These findings suggest that PPR infection could be associated with abortions in goat flocks found in these PPR endemic areas.

Creation of poxvirus expressing foot-and-mouth and peste des petits ruminant disease virus proteins

Foot-and-mouth disease (FMD) and Peste des petits ruminant disease (PPR) are acute and severe infectious diseases of sheep and are listed as animal diseases for compulsory immunization. However, there is no dual vaccine to prevent these two diseases. The Modified Vaccinia virus Ankara strain (MVA) has been widely used in the construction of recombinant live vector vaccine because of its large capacity of foreign gene, wide hostrange, high safety, and immunogenicity. In this study, MVA-GFP recombinant virus skeleton was used to construct dual live vector vaccines against FMD and PPR. The recombinant plasmid pUC57-FMDV P1-2A3CPPRV FH was synthesized and transfected into MVA-GFP infected CEF cells for homologous recombination. The results showed that a recombinant virus without fluorescent labeling was obtained after multiple rounds of plaque screening. The recombinant virus successfully expressed the target proteins, and the empty capsid of FMDV could be observed by transmission electron microscope (TME), and the expression levels of foreign proteins (VP1 and VP3) detected by ELISA were like those detected in FMDV-infected cells. This study laidthe foundation for the successful construction of a live vector vaccine against FMD and PPR. • A recombinant MVA expressing FMDVP12A3C and PRRV HF proteins • Both the FMDV and PRRV proteins inserted into the virus were expressed • The proteins expressed by the recombinant poxvirus were assembled into VLPs.

Seroprevalence of Foot and Mouth Disease (FMD) in Small Ruminants (Sheep and Goat) Slaughtered in Karu Abbatoir, Federal Capital Territory, Nigeria.

Foot and Mouth Disease is a contagious viral disease of cattle and sheep, causing ulceration of the hoofs and around the mouth. The role of small ruminants in FMD epidemiology is still poorly understood in Nigeria. The aim of the study is to determine the prevalence of Foot and Mouth Disease Virus (FMDV) antibodies in sheep and goats slaughtered in Karu abattoir. One hundred and twenty (120) sera each were collected from both sheep and goats and screened for FMDV antibodies using 3ABC ELISA. The result showed that 89 (74.2) of the sheep sera screened were positive for FMDV antibodies whereas 103 (85.8) of the goat sera were positive. It was more prevalent in goats. The finding indicates a characteristic maintenance host nature for FMD virus in small ruminants without apparent clinical signs. This study suggested an on-going infection in small ruminant co-herding with cattle as a risk factor. This risk factor may enhance FMD transmission associated with increased movement of infected live animals from endemic states to markets and abattoirs following livestock trade activities. FMD is a Transboundary Animal Disease (TAD) affecting livestock production and disrupting regional and international trade in animals and animal products. The detection of FMD antibodies in sheep and goats slaughtered in Karu abattoir suggests small ruminants play important roles in the epidemiology of Foot and Mouth Disease in Nigeria. Good tracking of origin and proper surveillance system for FMD in animals brought into the abbatoir to be slaughtered are recommended for a comprehensive prevention and control of the disease.

Longitudinal Study on Seroreactivity of Goats Exposed to Colostrum and Milk of Small Ruminant Lentivirus-infected Dams.

Small ruminant lentivirus (SRLV) causes caprine arthritis-encephalitis in goats and maedi-visna disease in sheep. Transmission is via ingestion of colostrum and milk from infected dams or long-term direct contact between animals. Lifelong seroconversion can occur several weeks after infection via ingestion. However, sub-yearling lambs that ingest contaminated colostrum may be able to clear the infection and become seronegative. Whether a similar phenomenon occurs in goats remains unknown. Therefore, the serological status of goats was studied longitudinally from the moment of natural exposure to colostrum and milk of SRLV-positive dams through the age of 24 months. Between February 2014 and March 2017 a dairy goat herd was studied which had been infected with SRLV for more than 20 years and carried maedi-visna virus-like genotype A subtype A17. Thirty-one kids born to dams seropositive for SRLV for at least a year beforehand were followed. They ingested colostrum immediately after birth and then remained with their dams for three weeks. The goats were tested serologically every month using two commercial ELISAs. The clinical condition of the goats was also regularly assessed. Out of 31 goats, 13 (42%) seroconverted at the age ranging from 3 to 22 months with a median of 5 months. Two goats seroconverted in the second year of life. The other eleven did so before the age of one year; two of these reverted to seronegative status. Only 9 out of 31 goats (29%) seroconverted in the first year of life and remained seropositive. They were early and stable seroreactors to which SRLV was transmitted lactogenically. The age at which they seroconverted ranged from 3 to 10 months with a median of 5 months. In 8 of the 18 persistently seronegative goats, a single isolated positive result occurred. No goats showed any clinical signs of arthritis. The level of maternal antibodies at the age of one week did not differ significantly between the stable seroreactors and the remainder. Seroconversion appears to occur in less than 50% of goats exposed to heterologous SRLV genotype A via ingestion of colostrum and milk from infected dams and is delayed by 3-10 months. The natural lactogenic route of transmission of SRLV genotype A in goats appears to be less effective than this route of genotype B transmission reported in earlier studies.

Identification, molecular characterization, and pathological features of orf virus in sheep and goats in Punjab province, Pakistan

Orf virus (ORFV) causes an acute, contagious, skin disease of sheep and goats which is economically important. The objectives of this study were to identify ORFV and to explore its pathological and phylogenetic profiles in 350 goats and 91 sheep of 14 districts of Punjab, Pakistan, from July 2020 to July 2021. Skin scrapings (total no. of samples = 441) of suspected animals were subjected to polymerase chain reactions, phylogenetic analysis, and pathological observations. The partial length of GIF/IL-2 gene (408bp) was successfully amplified in 58/441 samples. Phylogenetic analysis of GIF/IL2 gene showed that the study isolates belonged to ORFV-cluster I, together with the viruses reported in India and China. Pakistan ORFV isolates were shared 97.6-98.7% nucleotide and 97.6-100% amino acid identities with the reference strain (NC_005336). Moreover, Chinese ORFV-isolates were detected unique multiple amino acid substitutions (F11L, Q21H, D27N, I46V, N49S, N82D, D103N, S129G) with study isolates. Naturally infected animals were anorexic, emaciated, dull, and depressed. The macroscopic lesions included multifocal to coalescing, ulceration followed by proliferative papules, pustules, and crust formation on the epidermis of gums, lips, mouth commissure, muzzles, nose, and udder. Histopathological examination revealed hyperplasia, anastomosing rete ridges formation and degenerative changes, including spongiosis and vacuolation of epidermal cells. Keratinocytes exhibited eosinophilic intracytoplasmic inclusion bodies with pyknotic and karyorrhexis nuclei. This is the first report on molecular characterization of ORFV from Pakistan, with insight into its pathogenesis and comparative analysis of pathological alterations and genetic diversity between ORFV strains reported in different geographical areas.

Penerapan Teorema Bayes pada Sistem Pakar Pendeteksi Penyakit Domba

Sheep are one of the livestock that can provide benefits such as meat, milk, and skin which are used as a source of income for the community, especially in the Asahan regency area. However, still, the farmer's knowledge in terms of care and knowledge of sheep diseases can result in the sheep being able to die. The purpose of this study was to create an expert system to diagnose sheep disease using the theory of Bayes. The waterfall is used as a model in this study with stages, analysis, design, implementation, and testing. analysis was carried out to find the required data using observations and interviews. The design of this system consists of Unified Modeling Language (use case ), diagram classes, flowcharts, and interfaces. Testing the system uses a black box which aims to find out the functionality of the system that has been implemented, and data analysis using the theory of Bayes. Our findings resulted in bayes having an expert system for the diagnosis of diseases in sheep. The results of Bayes analysis with the theory of Bayes showed that the disease experienced in sheep is deworming with a probability level of 60.71%. The results of the black box test show that the functionality of this system is already running well

Whole-Genome Sequencing of Six Neglected Arboviruses Circulating in Africa Using Sequence-Independent Single Primer Amplification (SISPA) and MinION Nanopore Technologies.

On the African continent, a large number of arthropod-borne viruses (arboviruses) with zoonotic potential have been described, and yet little is known of most of these pathogens, including their actual distribution or genetic diversity. In this study, we evaluated as a proof-of-concept the effectiveness of the nonspecific sequencing technique sequence-independent single primer amplification (SISPA) on third-generation sequencing techniques (MinION sequencing, Oxford Nanopore Technologies, Oxford, UK) by comparing the sequencing results from six different samples of arboviruses known to be circulating in Africa (Crimean-Congo hemorrhagic fever virus (CCHFV), Rift Valley fever virus (RVFV), Dugbe virus (DUGV), Nairobi sheep disease virus (NSDV), Middleburg virus (MIDV) and Wesselsbron virus (WSLV)). All sequenced samples were derived either from previous field studies or animal infection trials. Using this approach, we were able to generate complete genomes for all six viruses without the need for virus-specific whole-genome PCRs. Higher Cq values in diagnostic RT-qPCRs and the origin of the samples (from cell culture or animal origin) along with their quality were found to be factors affecting the success of the sequencing run. The results of this study may stimulate the use of metagenomic sequencing approaches, contributing to a better understanding of the genetic diversity of neglected arboviruses.

Effects of Ovine Monocyte-Derived Macrophage Infection by Recently Isolated Toxoplasma gondii Strains Showing Different Phenotypic Traits.

Ovine toxoplasmosis is one the most relevant reproductive diseases in sheep. The genetic variability among different Toxoplasma gondii isolates is known to be related to different degrees of virulence in mice and humans, but little is known regarding its potential effects in sheep. The aim of this study was to investigate the effect of genetic variability (types II (ToxoDB #1 and #3) and III (#2)) of six recently isolated strains that showed different phenotypic traits both in a normalized mouse model and in ovine trophoblasts, in ovine monocyte-derived macrophages and the subsequent transcript expression of cytokines and iNOS (inducible nitric oxide synthase). The type III isolate (TgShSp24) showed the highest rate of internalization, followed by the type II clonal isolate (TgShSp2), while the type II PRU isolates (TgShSp1, TgShSp3, TgShSp11 and TgShSp16) showed the lowest rates. The type II PRU strains, isolated from abortions, exhibited higher levels of anti-inflammatory cytokines and iNOS than those obtained from the myocardium of chronically infected sheep (type II PRU strains and type III), which had higher levels of pro-inflammatory cytokines. The present results show the existence of significant intra- and inter-genotypic differences in the parasite-macrophage relationship that need to be confirmed in in vivo experiments.

Social behaviour and transmission of lameness in a flock of ewes and lambs.

Sheep have heterogenous social connections that influence transmission of some infectious diseases. Footrot is one of the top five globally important diseases of sheep, it is caused by Dichelobacter nodosus and transmits between sheep when infectious feet contaminate surfaces, e.g., pasture. Surfaces remain infectious for a few minutes to a few days, depending on surface moisture levels. Susceptible sheep in close social contact with infectious sheep might be at risk of becoming infected because they are likely to step onto infectious footprints, particularly dams and lambs, as they cluster together. High resolution proximity sensors were deployed on 40 ewes and their 54 lambs aged 5-27 days, in a flock with endemic footrot in Devon, UK for 13 days. Sheep locomotion was scored daily by using a 0-6 integer scale. Sheep were defined lame when their locomotion score (LS) was ≥2, and a case of lameness was defined as LS ≥2 for ≥2 days. Thirty-two sheep (19 ewes, 9 single, and 4 twin lambs) became lame during the study, while 14 (5 ewes, 5 single, and 4 twin lambs) were lame initially. These 46 sheep were from 29 family groups, 14 families had >1 lame sheep, and transmission from ewes to lambs was bidirectional. At least 15% of new cases of footrot were from within family transmission; the occurrence of lameness was higher in single than twin lambs. At least 4% of transmission was due to close contact across the flock. Most close contact occurred within families. Single and twin lambs spent 1.5 and 0.9 hours/day with their dams, respectively, and twin lambs spent 3.7 hours/day together. Non-family sheep spent only 0.03 hours/day in contact. Lame single lambs and ewes spent less time with non-family sheep, and lame twin lambs spent less time with family sheep. We conclude that most transmission of lameness is not attributable to close contact. However, in ewes with young lambs, some transmission occurs within families and is likely due to time spent in close contact, since single lambs spent more time with their dam than twin lambs and were more likely to become lame.

Evaluation of Clinical Accuracy of Portable Glucometers in Sheep at the Beginning of the Breeding Season

Measurements of blood glucose concentrations are frequently used to diagnose and monitor diseases in sheep. Portable blood glucometers are widely used in human medicine because of their practicality. However, there are not enough studies on the accuracy of these devices in sheep. In this study, it was aimed to determine the changes in the measurement values of two different portable blood glucometers and biochemistry autoanalyzer devices. The study was carried out on a total of 47 Kangal sheep, 17-18 months old, healthy and sick. According to the clinical examination, 35 healthy sheep (Group 1) and 12 patients whose hematocrit and total protein values were higher than the reference values were included in the study (Group 2). Glucose concentrations measured with portable glucometers were compared with the result obtained using the biochemistry autoanalyzer device. The agreement between the measured values was evaluated by Pearson correlation analysis and Bland-Altman plots. In addition, Tukey's test was performed to evaluate glucose measurement between groups. In the study found that there were -3.63% and 6.83% differences in the blood glucose measurement readings between the Optium Xceed (OX), On Call Pluss (CP), and biochemistry autoanalyzer devices in Group 1. These figures were found to be 6.08% and 9.66% in Group 2. The variety of measurement differences between the biochemistry autoanalyzer and glucometers should therefore be known in the clinical evaluation of blood glucose levels.

Management of breech presentation with a large pelvic hydatid cyst in late pregnancy in Tibet: a case report

BackgroundHydatid cystic disease (HCD) is primarily a disease of sheep and cattle. Human beings are accidental hosts. It is prevalent in the Tibet Autonomous Region (TAR) of China. In pregnancy, it can cause many complications.Case presentationWe present a multigravida with breech presentation at 37 weeks of pregnancy in whom a large pelvic hydatid cyst and multiple hepatic hydatids were diagnosed by ultrasonography. The large pelvic hydatid cyst was drained through the posterior fornix under the guidance of ultrasound, and an external cephalic version was performed. A healthy baby was delivered vaginally with head presentation at term.ConclusionHCD during pregnancy presents with management difficulty. It is important to formulate individualized treatment plans according to the actual situation of the patient and the local level of treatment.

Molecular diagnosis of peste des petits ruminants virus (PPR) in goats and sheep populations

Peste des petits ruminants (PPR) is an economically important viral disease of goats and sheep. The disease is confused clinically with other infections such as the mild strain of rinderpest in small ruminants. Effective control measures for PPR need that a proper and rapid diagnostic technique of disease. Therefore, the use of reverse transcriptase-polymerase chain reaction (RT-PCR) to detect suspected field samples collected from diseased goats and sheep in Dammam city, Kingdom of Saudia Arabia (KSA) has helped to give an effective diagnosis that was needed to control measure of the spread of the disease. This assay is based on the rapid purification of RNA on glass beads followed by the reverse transcription-polymerase chain reaction (RT-PCR). The primers (NP3/NP4) were used to amplify specifically a fragment of about 350 bp, that technique has a more specific and sensitive method for rapid diagnosis of disease.Key words: Peste des petits ruminants virus; reverse transcriptase polymerase chain reaction; diagnosis; goats; sheep

Characterization of Classical Sheep Scrapie in White-tailed Deer after Experimental Oronasal Exposure.

Classic scrapie is a prion disease of sheep and goats that is associated with accumulation of abnormal prion protein (PrPSc) in the central nervous and lymphoid tissues. Chronic wasting disease (CWD) is the prion disease of cervids. This study was conducted to determine the susceptibility of white-tailed deer (WTD) to the classic scrapie agent. We inoculated WTD (n = 5) by means of a concurrent oral/intranasal exposure with the classic scrapie agent from sheep or oronasally with the classic scrapie agent from goats (n = 6). All deer exposed to the agent of classic scrapie from sheep accumulated PrPSc. PrPSc was detected in lymphoid tissues at preclinical time points, and necropsies in deer 28 months after inoculation showed clinical signs, spongiform lesions, and widespread PrPSc in neural and lymphoid tissues. Western blots on samples from the brainstem, cerebellum, and lymph nodes of scrapie-infected WTD have a molecular profile similar to CWD and distinct from samples from the cerebral cortex, retina, or the original classic scrapie inoculum. There was no evidence of PrPSc in any of the WTD inoculated with classic scrapie prions from goats. WTD are susceptible to the agent of classic scrapie from sheep, and differentiation from CWD may be difficult.

20 Young Scholar Talk PHD: Implications of Histone Toxicity and Complement System Activity in Sheep and Cattle During Immunomodulatory States Including Respiratory Disease and Pregnancy

Abstract The immunostimulatory and toxic effects of extracellular histones have been demonstrated in humans and rodents suffering from acute respiratory distress syndrome and acute lung injury. Accumulating evidence suggests intricate interactions between extracellular histones and immune complement system proteins occur as a regulatory mechanism. However, limited information is available on the interactions of complement system activity and histone toxicity during immunomodulatory events in livestock. Therefore, our current research is aimed at investigating the contributions of histone toxicity and complement system activity in relation to respiratory disease and pregnancy in wild and domestic sheep and cattle. In an initial study, feedlot heifers were evaluated for protective capacity against extracellular histones and complement activity related to subsequent disease outcomes. At feedlot arrival, serum samples were collected from 118 heifer calves (BW 229 ± 2.4 kg) and subjected to a histone toxicity assay and a 50% hemolytic complement activity assay. Heifers were retrospectively assigned as either never receiving treatment with antibiotics for bovine respiratory disease (NT; n = 80) or calves that died from bovine respiratory disease within 1 wk of entering the feedlot (DA; n = 9). Serum from DA animals was less (P < 0.001) protective against histone toxicity compared to NT heifers. Likewise, complement activity of DA animals was reduced (P < 0.05) compared to NT animals. These results suggest cattle predisposed to severe cases of respiratory disease have impaired complement system activity presumably leading to reduced protection against histone toxicity. In a second study, wild Alaskan Dall sheep (Ovis dalli dalli) and domestic sheep (Ovis aries) were evaluated for susceptibility to histone toxicity. Serum was collected from Debouillet sheep (n = 150) with no clinical signs of illness and serum of wild Alaskan Dall sheep (n = 135) was collected from live capture and release animals. Dall sheep serum was less (P < 0.05) protective against histone toxicity compared to Debouillet sheep. Low protection against histone toxicity may be related to higher reported disease states for wild sheep. Furthermore, recognizing that disease modulates immune function, it is also recognized pregnancy relies on immune system activation. Therefore, pregnant sheep serum was evaluated to determine the effect of histone toxicity and complement system activity. Serum was collected from Debouillet ewes (n = 8) and analyzed for histone toxicity protectiveness and complement activity. Serum was collected from ewes prior to breeding (d -0) and at d 1 and 17 of the estrous cycle. Serum protective capacity against histones and complement activity was not significantly different on d -0 compared to d 1 and d 17. Collectively, these data implicate the toxic effect of extracellular histones and complement system activity during respiratory disease states with less obvious observations during pregnancy.