Control Sheep Research Articles

In situ assessment of neuroinflammatory cytokines in different stages of ovine natural prion disease.

According to the neuroinflammatory hypothesis, a cytokine-mediated host innate immune response may be involved in the mechanisms that contribute to the process of neurodegeneration. Specifically, regarding prion diseases, some experimental murine models have evidenced an altered profile of inflammatory intermediaries. However, the local inflammatory response has rarely been assessed, and never in tissues from different natural models throughout the progression of neurodegeneration. The aim of this study was to use immunohistochemistry (IHC) to in situ assess the temporal protein expression of several cytokines in the cerebellum of sheep suffering from various clinical stages of scrapie. Clear changes in the expression of most of the assessed markers were observed in the affected sheep compared to the healthy control sheep, and from different stages. In summary, this preliminary IHC study focusing in the Purkinje cell layer changes demonstrate that all cytokines or respective receptors studied (IL-1, IL-1R, IL-2R, IL-6, IL-10R, and TNFαR) except for IFNγR are disease-associated signaling proteins showing an increase or decrease in relation to the progression of clinical disease. In the future, this study will be extended to other inflammatory mediators and brain regions, focusing in particular on the release of these inflammatory mediators by astroglial and microglial populations.

Imaging Glucose Metabolism and Dopaminergic Dysfunction in Sheep (Ovis aries) Brain Using Positron Emission Tomography Imaging Reveals Abnormalities in OVT73 Huntington's Disease Sheep.

Huntington's disease (HD) is a neurodegenerative disease that causes cognitive, movement, behavioral, and sleep disturbances, which over time result in progressive disability and eventually death. Clinical translation of novel therapeutics and imaging probes could be accelerated by additional testing in well-characterized large animal models of HD. The major goal of our preliminary cross-sectional study is to demonstrate the feasibility and utility of the unique transgenic sheep model of HD (OVT73) in positron emission tomography (PET) imaging. PET imaging studies were performed in healthy merino sheep (6 year old, n = 3) and OVT73 HD sheep (5.5 year old, n = 3, and 11 year old, n = 3). Region-of-interest and brain atlas labels were defined for regional analyses by using a sheep brain template. [18F]fluorodeoxyglucose ([18F]FDG) was employed to compare the regional brain glucose metabolism and variations in FDG uptake between control and HD sheep. We also used [18F]fluoro-3,4-dihydroxyphenylalanine ([18F]FDOPA) to compare the extent of striatal dysfunction and evaluated the binding potential (BPND) in key brain regions between the groups. Compared with healthy controls and 11 year old HD sheep, the 5.5 year old HD sheep exhibited significantly increased [18F]FDG uptake in several cortical and subcortical brain regions (P < 0.05-0.01). No difference in [18F]FDG uptake was observed between healthy controls and 11 year old HD sheep. Analysis of the [18F]FDOPA BPND parametric maps revealed clusters of reduced binding potential in the 5.5 year old and 11 year old HD sheep compared to the 6 year old control sheep. In this first-of-its-kind study, we showed the usefulness and validity of HD sheep model in imaging cerebral glucose metabolism and dopamine uptake using PET imaging. The identification of discrete patterns of metabolic abnormality using [18F]FDG and decline of [18F]FDOPA uptake may provide a useful means of quantifying early HD-related changes in these models, particularly in the transition from presymptomatic to early symptomatic phases of HD.

Sleep disturbance in clinical and preclinical scrapie-infected sheep measured by polysomnography

Neurodegenerative diseases are characterised by neuronal loss and abnormal deposition of pathological proteins in the nervous system. Among the most common neurodegenerative diseases are Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease and transmissible spongiform encephalopathies (TSEs). Sleep and circadian rhythm disturbances are one of the most common symptoms in patients with neurodegenerative diseases. Currently, one of the main objectives in the study of TSEs is to try to establish an early diagnosis, as clinical signs do not appear until the damage to the central nervous system is very advanced, which prevents any therapeutic approach. In this paper, we provide the first description of sleep disturbance caused by classical scrapie in clinical and preclinical sheep using polysomnography compared to healthy controls. Fifteen sheep classified into three groups, clinical, preclinical and negative control, were analysed. The results show a decrease in total sleep time as the disease progresses, with significant changes between control, clinical and pre-clinical animals. The results also show an increase in sleep fragmentation in clinical animals compared to preclinical and control animals. In addition, sheep with clinical scrapie show a total loss of Rapid Eye Movement sleep (REM) and alterations in Non Rapid Eyes Movement sleep (NREM) compared to control sheep, demonstrating more shallow sleep. Although further research is needed, these results suggest that prion diseases also produce sleep disturbances in animals and that polysomnography could be a diagnostic tool of interest in clinical and preclinical cases of prion diseases.

Fear of the human 'super predator' in native marsupials and introduced deer in Australia.

Recent experiments have demonstrated that carnivores and ungulates in Africa, Asia, Europe and North America fear the human 'super predator' far more than other predators. Australian mammals have been a focus of research on predator naiveté because it is suspected they show atypical antipredator responses. To experimentally test if mammals in Australia also most fear humans, we quantified the responses of four native marsupials (eastern grey kangaroo, Bennett's wallaby, Tasmanian pademelon, common brushtail possum) and introduced fallow deer to playbacks of predator (human, dog, Tasmanian devil, wolf) or non-predator control (sheep) vocalizations. Native marsupials most feared the human 'super predator', fleeing humans 2.4 times more often than the next most frightening predator (dogs), and being most, and significantly, vigilant to humans. These results demonstrate that native marsupials are not naïve to the peril humans pose, substantially expanding the taxonomic and geographic scope of the growing experimental evidence that wildlife worldwide generally perceive humans as the planet's most frightening predator. Introduced fallow deer fled humans, but not more than other predators, which we suggest may result from their being introduced. Our results point to both challenges concerning marsupial conservation and opportunities for exploiting fear of humans as a wildlife management tool.

Poly(ADP-Ribose) Polymerases-Inhibitor Talazoparib Inhibits Muscle Atrophy and Fatty Infiltration in a Tendon Release Infraspinatus Sheep Model: A Pilot Study.

Structural muscle changes, including muscle atrophy and fatty infiltration, follow rotator cuff tendon tear and are associated with a high repair failure rate. Despite extensive research efforts, no pharmacological therapy is available to successfully prevent both muscle atrophy and fatty infiltration after tenotomy of tendomuscular unit without surgical repair. Poly(ADP-ribose) polymerases (PARPs) are identified as a key transcription factors involved in the maintenance of cellular homeostasis. PARP inhibitors have been shown to influence muscle degeneration, including mitochondrial hemostasis, oxidative stress, inflammation and metabolic activity, and reduced degenerative changes in a knockout mouse model. Tenotomized infraspinatus were assessed for muscle degeneration for 16 weeks using a Swiss Alpine sheep model (n = 6). All sheep received daily oral administration of 0.5 mg Talazoparib. Due to animal ethics, the treatment group was compared with three different controls from prior studies of our institution. To mitigate potential batch heterogeneity, PARP-I was evaluated in comparison with three distinct control groups (n = 6 per control group) using the same protocol without treatment. The control sheep were treated with an identical study protocol without Talazoparib treatment. Muscle atrophy and fatty infiltration were evaluated at 0, 6 and 16 weeks post-tenotomy using DIXON-MRI. The controls and PARP-I showed a significant (control p < 0.001, PARP-I p = 0.01) decrease in muscle volume after 6 weeks. However, significantly less (p = 0.01) atrophy was observed in PARP-I after 6 weeks (control 1: 76.6 ± 8.7%; control 2: 80.3 ± 9.3%, control 3: 73.8 ± 6.7% vs. PARP-I: 90.8 ± 5.1% of the original volume) and 16 weeks (control 1: 75.7 ± 9.9; control 2: 74.2 ± 5.6%; control 3: 75.3 ± 7.4% vs. PARP-I 93.3 ± 10.6% of the original volume). All experimental groups exhibited a statistically significant (p < 0.001) augmentation in fatty infiltration following a 16-week period when compared to the initial timepoint. However, the PARP-I showed significantly less fatty infiltration (p < 0.003) compared to all controls (control 1: 55.6 ± 6.7%, control 2: 53.4 ± 9.4%, control 3: 52.0 ± 12.8% vs. PARP-I: 33.5 ± 8.4%). Finally, a significantly (p < 0.04) higher proportion and size of fast myosin heavy chain-II fiber type was observed in the treatment group. This study shows that PARP-inhibition with Talazoparib inhibits the progression of both muscle atrophy and fatty infiltration over 16 weeks in retracted sheep musculotendinous units.

Gestational testosterone excess early to mid-pregnancy disrupts maternal lipid homeostasis and activates biosynthesis of phosphoinositides and phosphatidylethanolamines in sheep

Gestational hyperandrogenism is a risk factor for adverse maternal and offspring outcomes with effects likely mediated in part via disruptions in maternal lipid homeostasis. Using a translationally relevant sheep model of gestational testosterone (T) excess that manifests maternal hyperinsulinemia, intrauterine growth restriction (IUGR), and adverse offspring cardiometabolic outcomes, we tested if gestational T excess disrupts maternal lipidome. Dimensionality reduction models following shotgun lipidomics of gestational day 127.1 ± 5.3 (term 147 days) plasma revealed clear differences between control and T-treated sheep. Lipid signatures of gestational T-treated sheep included higher phosphoinositides (PI 36:2, 39:4) and lower acylcarnitines (CAR 16:0, 18:0, 18:1), phosphatidylcholines (PC 38:4, 40:5) and fatty acids (linoleic, arachidonic, Oleic). Gestational T excess activated phosphatidylethanolamines (PE) and PI biosynthesis. The reduction in key fatty acids may underlie IUGR and activated PI for the maternal hyperinsulinemia evidenced in this model. Maternal circulatory lipids contributing to adverse cardiometabolic outcomes are modifiable by dietary interventions.

Application of Titanium Mesh in the Early Treatment of Flail Chest

Objective: To investigate the effect of the titanium mesh on flail chest and bone healing from clinical and animal experiments.Methods: Clinical experiment: 24 patients with flail chests in our hospital from January 2020 to January 2023 were prospectively selected and divided into control and titanium mesh groups according to different treatment plans and basic data‐matching principles, with 12 cases in each group. The control group was treated with conservative external fixation, and the titanium mesh group was treated with titanium mesh fixation. The clinical efficacy index, visual analog scale and blood gas indexes and hemodynamic indexes of the two groups of patients were recorded. Chest CT and pulmonary function and life quality were examined after operation. Animal experiment: The flail chest sheep were treated conservatively with a titanium mesh, and the expression of bone‐healing‐related proteins was detected.Results: The mechanical ventilation time, drain indwelling time, ICU observation time, and hospital time in the titanium mesh group were significantly shorter than those in the control group (p &lt; 0.05). The PaO2, CVP, FVC, FEV1, MVV, and life quality of the titanium mesh group were significantly better than those of the control group after operation, and the visual analog scale, PaCO2, CI, ELWI, and the proportions of atelectasis, thoracocyllosis, and consolidation tardive after operation were significantly lower than those of the control group (p &lt; 0.05). The expressions of BMP2, IGF‐1, VEGF, and PDGFD in the rib tissue of titanium mesh sheep were higher than those of control sheep at 4 weeks after operation (p &lt; 0.05).Conclusion: Titanium mesh is a safe and effective treatment for flail chest, which can improve pain, blood gas, hemodynamic indexes, and pulmonary function and promote fracture healing.

Influence of nitric oxide delivery on kidney damage in experimental model of cardiopulmonary bypass with circulatory arrest

Aim. To evaluate the efficiency and safety of nitric oxide delivery for kidney protection in the simulation of cardiopulmonary bypass and circulatory arrest in the experiment.Materials and Methods. We performed an experimental modeling of cardiopulmonary bypass with circulatory arrest in 20 sheep of the Altai breed weighing 30-32 kg. Circulatory arrest was performed at moderate hypothermia (30-32°C) for 15 minutes and was followed by reperfusion and warming up to 37°C. Animals were divided into 2 equal groups: 10 sheep which received nitric oxide (NO) through the inhalations supply and cardiopulmonary bypass machine at a dose of 80 ppm, and 10 control sheep. We further collected biological fluids and tissue specimens for subsequent assessment of the safety of NO use and its nephropro-tective properties.Results. The proposed method of NO therapy during the cardiopulmonary bypass with circulatory arrest was safe and did not lead to an increase in toxic metabolites. In sheep which received NO therapy, the average concentration of NO2 throughout the entire period of the experiment was 1.2 ± 0.19 ppm (with a maximum allowable concentration of 3.0 ppm), and the concentration of methemoglobin (MetHb) was 2.3 ± 0.34% (with a maximum allowable level of 5.0%). Neutrophilic gelatinase-associated lipocalin (NGAL) was significantly lower in sheep which received NO therapy (0.67 ± 0.255 ng/mL versus 2.23 ± 0.881 ng/mL in the control group, p = 0.0001). Acute kidney injury was mitigated in sheep which received NO therapy.Conclusion. Experimental delivery of NO at a dose of 80 ppm during the cardiopulmonary bypass and circulatory arrest is safe and is associated with reduced acute kidney injury.

Placental assessment using spectral analysis of the envelope of umbilical venous waveforms in sheep

IntroductionThis study was designed to test the efficacy of an ultrasound flow measurement method to evaluate placental function in a hyperandrogenic sheep model that produces placental morphologic changes and an intrauterine growth restriction (IUGR) phenotype. Materials and methodsPregnant ewes were assigned randomly between control (n = 12) and testosterone-treatment (T-treated, n = 22) groups. The T-treated group was injected twice weekly intramuscularly (IM) with 100 mg testosterone propionate. Control sheep were injected with corn oil vehicle. Lambs were delivered at 119.5 ± 0.48 days gestation. At the time of delivery of each lamb, flow spectra were generated from one fetal artery and two fetal veins, and the spectral envelopes examined using fast Fourier transform analysis. Base 10 logarithms of the ratio of the amplitudes of the maternal and fetal spectral peaks (LRSP) in the venous power spectrum were compared in the T-treated and control populations. In addition, we calculated the resistive index (RI) for the artery defined as ((peak systole – min diastole)/peak systole). Two-tailed T-tests were used for comparisons. ResultsLRSPs, after removal of significant outliers, were −0.158 ± 0.238 for T-treated and 0.057 ± 0.213 for control (p = 0.015) animals. RIs for the T-treated sheep fetuses were 0.506 ± 0.137 and 0.497 ± 0.086 for controls (p = 0.792) DiscussionLRSP analysis distinguishes between T-treated and control sheep, whereas RIs do not. LRSP has the potential to identify compromised pregnancies.

Metabolomic Analysis of Plasma in Huntington's Disease Transgenic Sheep (Ovis aries) Reveals Progressive Circadian Rhythm Dysregulation.

Metabolic abnormalities have long been predicted in Huntington's disease (HD) but remain poorly characterized. Chronobiological dysregulation has been described in HD and may include abnormalities in circadian-driven metabolism. Here we investigated metabolite profiles in the transgenic sheep model of HD (OVT73) at presymptomatic ages. Our goal was to understand changes to the metabolome as well as potential metabolite rhythm changes associated with HD. We used targeted liquid chromatography mass spectrometry (LC-MS) metabolomics to analyze metabolites in plasma samples taken from female HD transgenic and normal (control) sheep aged 5 and 7 years. Samples were taken hourly across a 27-h period. The resulting dataset was investigated by machine learning and chronobiological analysis. The metabolic profiles of HD and control sheep were separable by machine learning at both ages. We found both absolute and rhythmic differences in metabolites in HD compared to control sheep at 5 years of age. An increase in both the number of disturbed metabolites and the magnitude of change of acrophase (the time at which the rhythms peak) was seen in samples from 7-year-old HD compared to control sheep. There were striking similarities between the dysregulated metabolites identified in HD sheep and human patients (notably of phosphatidylcholines, amino acids, urea, and threonine). This work provides the first integrated analysis of changes in metabolism and circadian rhythmicity of metabolites in a large animal model of presymptomatic HD.

Role of the succinate and GPR91 pathway in atrial fibrillation mechanisms

Atrial fibrillation (AF) is the most common arrhythmia and is associated with increased morbidity and mortality. The mechanisms underlying the transition from paroxysmal to persistent AF are still a matter of debate. Recent studies indicate a potential role for metabolic remodelling in the AF stabilization process and increased levels of a specific metabolic substrate, succinate, have been found in blood plasma of AF patients. While succinate is known to increase reactive oxygen species (ROS) production, the role of the succinate receptor (GPR91) in atrial function is unknown. To assess the impact of the succinate pathway on AF vulnerability in a sheep model. GPR91 expression levels were quantified by Western Blot (WB) in a previously described sheep model of persistent AF induced by burst-pacing. Optical experiments were subsequently performed in ex vivo right atria (RA) from control sheep (n = 5). RA were perfused by Tyrode solution, then supplemented with the cis-epoxysuccinic acid (cESA), a specific activator of GPR91 (150 μM) to study its involvement in atrial electrophysiology and AF. Action potential duration at 80% of repolarization (APD80) were assessed from 2 to 5 Hz pacing frequency. We used an S1S2 pacing protocol to determine effective refractory period (ERP) and a burst pacing protocol (30 Hz) to assess ex vivo AF vulnerability. Finally, we investigated these properties in a human RA from an AF patient. WB experiments revealed an increase in GPR91 expression in AF sheep compared to sham sheep. Interestingly, in resistant sheep (no AF after 90 days of burst pacing), expression levels were decreased compared to sham. During cESA perfusion in control sheep RA, sinus rhythm (119 vs. 95 bpm; P = 0.03) and ERP (202 vs. 178 ms; P = 0.36) were decreased when compared to baseline. We also observed a decrease in APD80 (199 vs. 177 ms; P = 0.009) and in CV (127 vs. 115 cm/sec; P = 0.01). These electrophysiological perturbations led to an increase in AF vulnerability by burst pacing (0% vs. 60%) and an increase in spontaneous arrhythmias. These results were corroborated in the human RA were cESA decreased APD80 (265 vs. 241 ms), ERP (240 vs. 220 ms), and CV (119 vs. 94 cm/sec) and increased arrhythmia vulnerability. For the first time, we demonstrated that GPR91 is expressed in atrial tissue and that its activation through succinate can play a major role in AF mechanisms.

PO-01-159 ROLE OF THE SUCCINATE PATHWAY IN ATRIAL FIBRILLATION MECHANISMS

Atrial fibrillation (AF) is the most common arrhythmia and is associated with increased morbidity and mortality. The mechanisms underlying the transition from paroxysmal to persistent AF are still a matter of debate. Recent studies indicate a potential role for metabolic remodelling in the AF stabilization process and increased levels of a specific metabolic substrate, succinate, have been found in blood plasma of AF patients. While succinate is known to increase reactive oxygen species (ROS) production, the role of the succinate receptor (GPR91) in atrial function is unknown. To assess the impact of the succinate pathway on AF vulnerability in a sheep model. GPR91 expression levels were quantified by Western Blot (WB) in a previously described sheep model of persistent AF induced by burst-pacing. Optical experiments were subsequently performed in ex vivo right atria (RA) from control sheep (N=5). RA were perfused by Tyrode solution, then supplemented with the cis-epoxysuccinic acid (cESA), a specific activator of GPR91 (150μM) to study its involvement in atrial electrophysiology and AF. Action potential duration at 80% of repolarization (APD80) were assessed from 2 to 5Hz pacing frequency. We used an S1S2 pacing protocol to determine effective refractory period (ERP) and a burst pacing protocol (30Hz) to assess ex vivo AF vulnerability. Finally, an organ donation program allowed us to investigate these properties in a human RA from an AF patient. WB experiments revealed an increase in GPR91 expression in AF sheep compared to sham sheep. Interestingly, in resistant sheep (no AF after 90 days of burst pacing), expression levels were decreased compared to sham. During cESA perfusion in control sheep RA, sinus rhythm (119 vs 95 bpm; p=0,03) and ERP (202 vs 178 ms; p=0,36) were decreased when compared to baseline. We also observed a decrease in APD80 (199 vs 177 ms; p=0.009) and in CV (127 vs 115 cm/sec; p=0.01). These electrophysiological perturbations led to an increase in AF vulnerability by burst pacing (0% vs 60%) and an increase in spontaneous arrhythmias. These results were corroborated in the human RA were cESA decreased APD80 (265 vs 241 ms), ERP (240 vs 220 ms), and CV (119 vs 94 cm/sec) and increased arrhythmia vulnerability. For the first time, we demonstrated that GPR91 is expressed in atrial tissue and that its activation through succinate can play a major role in AF mechanisms.

Rumen protozoa population and carbohydrate-digesting enzymes in sheep fed a diet supplemented with hydrolysable tannins

Abstract The aim of the study was to compare the effect of adding different sources of hydrolysable tannins to the sheep diet on protozoa population and carbohydrate digestion in the rumen. The study was performed in 3 Polish Lowland ewes fistulated to the rumen in a 3 × 3 Latin square design. Control sheep (CON) received (g/d): meadow hay (600), barley meal (300), soybean meal (100) and vitamin-mineral premix (20). Sheep from the experimental groups were additionally administered 12.6 g/kg DM oak bark extract (OAK) and 3.91 g/kg DM tannic acid (TAN ). The net consumption of tannins was approx. 0.4% DM for both additives. Regarding the count of protozoa, a significant interaction between diet and sampling time was documented for all ciliates (P&lt;0.01), with a significant effect of both factors when considered separately. Experimental diets reduced the number of total protozoa and Entodinium spp. (before feeding, 2 and 4 h after feeding; P&lt;0.01), while increasing the abundance of Isotricha spp. population (4 h after feeding; P&lt;0.01) in the rumen. Interestingly, the count of Ophryoscolex spp. after feeding the TAN diet increased before feeding and 2 h after feeding in comparison to the CON and OAK groups, respectively, and subsequently decreased compared to the CON diet (4 and 8 h after feeding, P&lt;0.01). A significant interaction between the diet and sampling time was observed for xylanolytic activity (P&lt;0.01) in the rumen, with a significant effect of sampling time, which decreased its activity in CON (after feeding) and OAK sheep (2 h after feeding; P&lt;0.01). For amylolytic activity (P&lt;0.10), there was a trend towards a significant interaction between experimental factors, with a significant effect on both diet and sampling time. Detailed analysis showed that the TAN diet significantly reduced amylolytic activity 2 h after feeding compared to the CON group (P&lt;0.05). In conclusion, the TAN diet significantly reduced the number of total protozoa and Entodinium spp., which consequently reduced amylolytic activity in the rumen, without any significant effect on pH and carbohydrate fermentation in the rumen.

Digestibility, Growth Performance, Body Measurement and Hormone of Sheep Fed with Different Levels of Brachiaria decumbens Diets.

Limited data are available regarding the effects of Brachiaria decumbens on sheep's growth performance at different times. Therefore, this current study focused on sheep's nutrient apparent digestibility, feed efficiency, body index, and growth hormone when they are fed with low and high levels of B. decumbens diets. A total of 30 six-month-old male Dorper cross sheep were divided randomly into three treatment groups with 10 sheep per treatment. Treatment 1 (control) sheep were fed with Pennisetum purpureum and pellets as the basal diet, whereas Treatment 2 and 3 sheep were fed with feed mixed with low (10%) and high (60%) levels of B. decumbens, respectively. The study was conducted in two phases consisting of short-term feeding (seven days) and long-term feeding (90 days). Throughout the experiment, daily fecal voided were collected in the morning for seven days continuous before the end of each feeding phases for the determination of nutrient apparent digestibility. The amount of feed offered and refusals plus body weight gain were recorded daily to determine the feed efficiency (FE). Besides, the body measurements of each sheep from every treatment were measured weekly and blood samples were collected for the analysis of growth hormone (GH) concentration. There were significant differences (p < 0.05) in the nutrient apparent digestibility, growth performance, body measurement, and GH concentration among treatment sheep throughout the study period. Treatment 3 sheep fed with 60% of B. decumbens diet revealed the lowest dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) digestibility during the long-term feeding. Likewise, Treatment 3 (T3) sheep had the lowest total bodyweight gain, average daily gain, total feed intake, and daily feed intake among treatment sheep. The heart girth index (HGI) of T3 sheep was also significantly lower during the short-term feeding. Moreover, the GH concentration of T3 sheep was significantly lower as compared to the control that decreases steadily throughout the study period. In conclusion, high levels of B. decumbens showed the most significant results out of all three treatments indicating the presence of saponins, which produce negative effects on the sheep's overall performance.

Evaluation of Clinical and Biochemical Traits in Egyptian Barki Sheep with Different Growth Performances.

The Barki sheep industry is becoming increasingly important in Egypt because of the high quality of their meat and wool. This sheep breed is also commonly known for its resistance to arid and harsh environmental conditions. Such characteristics can be exploited in solving the problematic situation of inadequate animal protein for human consumption, particularly under climatic changes. However, very few studies have investigated aspects of breeding, nutrition, and susceptibility to infectious or non-infectious diseases in Barki sheep. Herein, we propose to unravel the differences in the clinical and biochemical profiles among Barki sheep of different growth rates. We measured clinical and biochemical parameters in stunted (n = 10; test group) and in good body condition (n = 9; control group) Barki sheep. Animals subjected to this experiment were of the same sex (female), age (12 months old), and housed in the same farm with similar conditions of feeding, management practice, and vaccination and deworming regimens. Regarding clinical examination, stunted/tested sheep showed a significantly higher pulse and respiratory rate compared to sheep with a good body condition/control group. The appetite, body temperature, and digestion processes were the same in both groups. In biochemical investigations, nutritional biomarkers were reduced markedly in stunted sheep compared with the control sheep, including total protein (p = 0.0445), albumin (p = 0.0087), cholesterol (p = 0.0007), and triglycerides (p = 0.0059). In addition, the Barki sheep test group suffered from higher levels of urea and blood urea nitrogen than the control group. Consistently, growth and thyroid hormone levels were lower in stunted sheep than the control sheep, although the differences were not statistically significant (p > 0.05). No significant differences were detected in both groups for serum levels of calcium, phosphorus, magnesium, iron, and zinc (p > 0.05). To detect the reasons for emaciation, certain debilitating infections were tested. All tested sheep showed negative coprological tests for gastrointestinal parasites, and had no obvious seropositivity to brucellosis, toxoplasmosis, neosporosis, or Q fever. This study demonstrates the useful biochemical markers for monitoring growth performance in Egyptian Barki sheep and unravels the usefulness of this breed in nationwide breeding and farming.

Identifying hepatic genes regulating the ovine response to gastrointestinal nematodes using RNA-Sequencing.

Gastrointestinal nematode (GIN) infections are considered the most important disease of grazing sheep and due to increasing anthelmintic resistance, chemical control alone is inadequate. Resistance to Gastrointestinal nematode infection is a heritable trait, and through natural selection many sheep breeds have higher resistance. Studying the transcriptome from GIN-exposed and GIN-unexposed sheep using RNA-Sequencing technology can provide measurements of transcript levels associated with the host response to Gastrointestinal nematode infection, and these transcripts may harbor genetic markers that can be used in selective breeding programs to enhance disease resistance. The objective of this study was to compare liver transcriptomes of sheep naturally exposed to Gastrointestinal nematode s, with either high or low parasite burdens, to GIN-unexposed control sheep in order to identify key regulator genes and biological processes associated with Gastrointestinal nematode infection. Differential gene expression analysis revealed no significant differentially expressed genes (DEG) between sheep with a high or low parasite burden (p-value ≤0.01; False Discovery Rate (FDR) ≤ 0.05; and Fold-Change (FC) of > ±2). However, when compared to the control group, low parasite burden sheep showed 146 differentially expressed genes (64 upregulated and 82 downregulated in the low parasite burden group relative to the control), and high parasite burden sheep showed 159 differentially expressed genes (57 upregulated and 102 downregulated in the low parasite burden group relative to the control) (p-value ≤0.01; FDR ≤0.05; and FC of > ±2). Among these two lists of significant differentially expressed genes, 86 differentially expressed genes (34 upregulated, 52 downregulated in the parasited group relative to the control) were found in common between the two parasite burden groups compared to the control (GIN-unexposed sheep). Functional analysis of these significant 86 differentially expressed genes found upregulated genes involved in immune response and downregulated genes involved in lipid metabolism. Results of this study offer insight into the liver transcriptome during natural Gastrointestinal nematode exposure that helps provide a better understanding of the key regulator genes involved in Gastrointestinal nematode infection in sheep.

Rapid and accurate screening of cystic echinococcosis in sheep based on serum Fourier-transform infrared spectroscopy combined with machine learning algorithms.

Cystic echinococcosis (CE) in sheep is a serious zoonotic parasitic disease caused by Echinococcus granulosus sensu stricto (s.s.). Presently, the screening technology for CE in sheep is time-consuming and inaccurate, and novel screening technology is urgently needed. In this work, we combined machine-learning algorithms with Fourier transform infrared (FT-IR) spectroscopy of serum to establish a quick and accurate screening approach for CE in sheep. Serum samples from 77 E. granulosus s.s.-infected sheep to 121 healthy control sheep were measured by FT-IR spectrometer. To optimize the classification accuracy of the serum FI-TR method for the E. granulosus s.s.-infected sheep and healthy control sheep, principal component analysis (PCA), linear discriminant analysis, and support vector machine (SVM) algorithms were used to analyze the data. Among all the bands, 1500-1700 cm-1 band has the best classification effect; its diagnostic sensitivity, specificity, and accuracy of PCA-SVM were 100%, 95.74%, and 96.66%, respectively. The study showed that serum FT-IR spectroscopy combined with machine learning algorithms has great potential for rapid and accurate screening methods for the CE in sheep.

Experimental infection of sheep at mid-pregnancy with archetypal type II and type III Toxoplasma gondii isolates exhibited different phenotypic traits

Toxoplasma gondii is a major cause of reproductive failure in small ruminants. Genotypic diversity of T. gondii strains has been associated with variations in phenotypic traits in in vitro and murine models. However, whether such diversity could influence the outcome of infection in small ruminants remains mostly unexplored. Here, we investigate the outcome of oral challenge in sheep at mid-pregnancy with 10 sporulated oocysts from three different T. gondii isolates belonging to archetypal II and III and selected according to their genetic and phenotypic variations shown in previous studies. Seventy-three pregnant sheep were divided in four groups: G1 infected with TgShSp1 isolate (type II, ToxoDB#3), G2 with TgShSp16 isolate (type II, ToxoDB#3), G3 with TgShSp24 isolate (type III, ToxoDB#2) and G4 of uninfected control sheep. Two different approaches were carried out within this study: (i) the outcome for the pregnancy after infection (n = 33) and (ii) the lesions and parasite tropism and burden at 14 and 28 days post infection (dpi) (n = 40). The onset of hyperthermia and seroconversion occurred one and two days later, respectively in G1 when compared to G2 and G3. However, sheep that suffered from reproductive failure, either by abortion, foetal dead at the time of euthanasia or stillbirth were similar among infected groups (50%, 40% and 47%, respectively). Histological lesions in placentomes and foetal tissues from euthanized animals from the second approach were only detected at 28 dpi and mainly in G1. At 14 dpi, T. gondii-DNA was only detected in G1 in the 11% of the placentomes. However, at 28 dpi the frequency of detection in placentomes was higher in G1 (96%) than in G2 and G3 (7% and 47%, respectively) besides in foetuses was lower in G2 (20%) than in G1 and G3 (100% and 87%, respectively). Regarding late abortions, stillbirths, and lambs of G1, G2 and G3, the frequency of microscopic lesions was similar between groups (79%, 78% and 67%, respectively) whereas T. gondii-DNA was evidenced in 100%, 55% and 100%, respectively. These recently obtained T. gondii isolates led to similar reproductive losses but intra- and inter-genotype variations in the rise of hyperthermia, dynamics of antibodies, frequency of lesions and parasite detection and distribution. Thus, the different phenotypic traits of the isolates could influence the outcome of the infection and mechanisms responsible for it, and further investigations are warranted.

Shared stressful experiences affect social proximity in Merino sheep.

While it is well established that humans develop stronger relationship bonds when they share stressful experiences, there is little known on how shared stressful experiences may influence relationship bonding in animals. Here, we present a study looking at social proximity between individuals in small groups of Merino ewes following a shared stressful experience compared with control sheep that were not exposed to stress. Some sheep were familiar to each other. Analyses of social proximity using real-time-kinematic Global Navigation Satellite System (GNSS) on-animal devices showed sheep preferred to be closest to familiar individuals, but across the study duration they also developed a preference for the individuals they shared the stressful experience with, relative to their proximity to control individuals. These results contribute to limited research on what factors may instigate the development of bonds between unfamiliar sheep. Between-individual bonds may develop as a means of socially mediated stress buffering. Social bonding following a shared stressful experience aligns with human social relationships and increases our understanding of how animals perceive their conspecifics in relation to stressful environmental change.

Developmental programming: Preconceptional and gestational exposure of sheep to a real-life environmental chemical mixture alters maternal metabolome in a fetal sex-specific manner

BackgroundEveryday, humans are exposed to a mixture of environmental chemicals some of which have endocrine and/or metabolism disrupting actions which may contribute to non-communicable diseases. The adverse health impacts of real-world chemical exposure, characterized by chronic low doses of a mixture of chemicals, are only recently emerging. Biosolids derived from human waste represent the environmental chemical mixtures humans are exposed to in real life. Prior studies in sheep have shown aberrant reproductive and metabolic phenotypes in offspring after maternal biosolids exposure. ObjectiveTo determine if exposure to biosolids perturbs the maternal metabolic milieu of pregnant ewes, in a fetal sex-specific manner. MethodsEwes were grazed on inorganic fertilizer (Control) or biosolids-treated pastures (BTP) from before mating and throughout gestation. Plasma from pregnant ewes (Control n = 15, BTP n = 15) obtained mid-gestation were analyzed by untargeted metabolomics. Metabolites were identified using Agilent MassHunter. Multivariate analyses were done using MetaboAnalyst 5.0 and confirmed using SIMCA. ResultsUnivariate and multivariate analysis of 2301 annotated metabolites identified 193 differentially abundant metabolites (DM) between control and BTP sheep. The DM primarily belonged to the super-class of lipids and organic acids. 15-HeTrE, oleamide, methionine, CAR(3:0(OH)) and pyroglutamic acid were the top DM and have been implicated in the regulation of fetal growth and development. Fetal sex further exacerbated differences in metabolite profiles in the BTP group. The organic acids class of metabolites was abundant in animals with male fetuses. Prenol lipid, sphingolipid, glycerolipid, alkaloid, polyketide and benzenoid classes showed fetal sex-specific responses to biosolids. DiscussionOur study illustrates that exposure to biosolids significantly alters the maternal metabolome in a fetal sex-specific manner. The altered metabolite profile indicates perturbations to fatty acid, arginine, branched chain amino acid and one‑carbon metabolism. These factors are consistent with, and likely contribute to, the adverse phenotypic outcomes reported in the offspring.