Sheep Ovis Research Articles

Our stubborn prejudice about donkeys is shifting as they protect Australia's sheep from wild dogs

Our complex and contradictory relationships with animals is demonstrated in our relationships with donkeys Equus asinus. The Australian context exemplifies these conflicting attitudes: once exploited as a beast of burden in the Outback in colonial times, the donkey has since been constructed as a pest to farmers, a feral animal that does not belong, and vermin to be exterminated. The latest incarnation is interesting as the donkey is once again proving ‘valuable’ as the guardian animal of choice for some farmers and pastoralists seeking to protect their flocks from wild dogs Canis lupus familiaris. There is an interesting inter-relationship between the domestic animals in this context: the sheep Ovis aries (valuable to humans), the wild animals: the dogs, (valued as the usual favoured companion but in this context, as a pest to be destroyed) and the donkeys (valuable again in their guardian role rather than a feral pest to be shot). To add to the irony of this situation, some of the donkeys employed in th...

Comparative characteristics of shoulder blade (Scapula) and shoulder bone (Humerus) of roe deer (Capreolus capreolus) and sheep (Ovis aries) in order to determine the animal species

In illegal hunting it is often possible only on the basis of morphological characteristics to determine the animal species. By the method of comparison there was performed the forensic analysis of roe deer and sheep osteological features. For the purpose of investigating the shoulder blade (Scapula) and shoulder bone (Humerus) comparative characteristics, there were used 6 shoulder blades and 6 shoulder bones of roe deer and 8 shoulder blades and 8 shoulder bones of sheep. After the skin, muscles, arterial, venous and lymphatic vessels as well as nerves were removed from the bones, they were thermally treated in an autoclave. Subsequently, the bones were placed in 3% solutioin of hydrogen peroxide (H2O2) for bleaching and degreasing. Then they were air dried and then photographed. Shoulder blade (Scapula) is a bone plate (Ossa plana) roughly triangular in shape. Scapular spine (Spina scapulae) is much more prominent in roe deer with acromion blade in the form of spike, while in sheep it is shorter and ends with acrimion at a right angle. Shoulder blade cup (Cavitas glenoidalis) in roe deer is round in shape, and in sheep it is oval. Tuberculum supraglenoidale and Processus coracoideus in sheep are more and in roe deer less developed. Shoulder bone (Humerus) in roe deer is relatively long, slender bone with proximal convexity turned cranially in regard to the same bone in sheep, which is stronger and heavier. Tuberculum majus in roe deer is less developed, and in sheep it is in a form of solid bone protuberance. Tuberculum minus and Tuberositas deltoidea in sheep are more developed than in roe deer. At medial condyle (Condylus medialis) in sheep there is shallow and wide groove, while in roe deer it is deeper and narrower. On the basis of morphological differences of roe deer and sheep bones, it can be determined with certainty which animal spesies they belong to.

Effects of water hyacinth silage in diets on feed intake, digestibility and rumen parameters of sheep (Ovis aries) in the Mekong Delta of Vietnam

Effects of water hyacinth silage in diets on feed intake, digestibility and rumen parameters of sheep (Ovis aries) in the Mekong Delta of Vietnam

Lungworm (Nematoda: Protostrongylidae) infection in wild and domestic ruminants from Małopolska region of Poland.

The conducted study has focused on domestic, as well as wild ruminant species. The post mortem examination was carried out on 68 animals, including three wild species: roe deer (Capreolus capreolus) (25 indyviduals), red deer (Cervus elaphus) (6), fallow deer (Dama dama) (5) and two domestic: sheep (Ovis aries) (14) and cattle (Bos taurus) (18). Some of the species have also been investigated in the field by the coproscopical analyses. The faecal samples from roe deer (27), fallow deer (20), red deer (36) and moose (Alces alces) (10) were collected from the environment, while from sheep (10) and goat (Capra hircus) (10)--per rectum. Based on the obtained results the following values were calculated: prevalence, mean intensity and intensity range. The post mortem examination did not reveal pulmonary nematodes neither in domestic nor in wild ungulates, however, the larvae of aforementioned parasites were often stated in the stool samples taken from the environment. All wild species, except fallow deer were infected. Consequently, six species of lungworms have been identified. The first stage larvae of Varestrongylus capreoli occurred in 11 samples of roe deer and Varestrongylus alces in one moose. The larvae of Elaphostrongylus cervi were found in 19 red deer and Varestrongylus sagittatus in 3. Furthermore, Elaphostrongylus alces larvae were noted in 6 moose. Within domestic ruminants only one sheep and two goats were infected by Muellerius capillaris.

Roads, routes and rams: does sexual segregation contribute to anthropogenic risk in a desert-dwelling ungulate?

Context Little is known about the consequences of sexual segregation (differential use of resources by the sexes outside of the mating season) for the conservation of large mammals. Roadways (i.e. the strip of land over which a road or route passes) are ubiquitous around the world, and are a major cause of wildlife mortality, as well as habitat loss and fragmentation. Many populations of bighorn sheep (Ovis canadensis) occur at low densities and in a metapopulation structure. Roadways could affect movements of males and females differentially, an outcome that has not been considered previously. Aims We investigated the propensity of the sexes to cross a paved two-lane road and a single-lane, maintained dirt route and predicted that adult males, because of their life-history characteristics, would cross those roadways more often than females. Methods We investigated movements of male and female bighorn sheep from 1986 to 1990. We used a fixed-wing aircraft with an H-antenna on each wing strut to locate individuals each week from October 1986 to December 1990. We estimated the degree of overlap among 50% core areas of use by males and females with the utilisation distribution overlap index (UDOI). Key results We relocated male and female bighorn sheep on 948 occasions during sexual aggregation and on 1951 occasions during sexual segregation. More males than females were likely to cross both types of roadways during segregation, and the dirt route during aggregation. Propensity of males and females to cross roadways was strongly influenced by time of year (i.e. whether the period of sexual aggregation or sexual segregation). The lowest overlap in 50% core areas was between females and males during periods of segregation (UDOI = 0.1447). Conclusions More males than females crossed Kelbaker Road and the unnamed dirt route during segregation, as well as the unnamed route during aggregation. Both of those features could affect males more than females, and could result in reductions in the use of habitat or increased mortality of bighorn sheep from vehicle collisions as a result of spatial segregation of the sexes. Implications During environmental review, biologists should consider sexual segregation when assessing potential anthropogenic effects on movements of bighorn sheep. Biologists also should consider sexual segregation and how roadways, even lightly traveled routes, affect movements of male and female ungulates differently before manipulating habitat, translocating animals, or constructing or modifying roadways.

Growth hormone polymorphisms and growth traits in Chinese Tibetan sheep Ovis aries.

Growth hormone (GH) plays an important role in promoting growth, protein and muscle accretion, and fat catabolism, suggesting that GH is a potential candidate gene affecting growth traits in vertebrates. In this paper, polymorphisms in GH were investigated in 632 Chinese Tibetan sheep, by using DNA sequencing. Three single nucleotide polymorphisms were identified, including two mutations (g.616G>A and g.624G>A) in intron 2 and one synonymous mutation (g.498G>C) in exon 2. Association analyses showed that both g.498G>C and g.616G>A were significantly associated with several growth traits (at P < 0.01 or P < 0.05) in three investigated breeds. Our results demonstrate that GH variation may be used as a molecular marker for growth traits in Chinese Tibetan sheep.

Characterization of the complete mitochondrial genome sequence of Ujumuqin sheep (Ovis aries)

Sheep is one of the most important and widespread domestic animals. Nevertheless, the origins of most sheep breeds are poorly understood, specifically the fat-tailed sheep that maternally originates from a specific group. Here, we reported the whole mitochondrial DNA of Ujumuqin sheep (Ovis aries), derived from one of the oldest fat-tailed sheep breed-Mongolian sheep in China. It harbors 2 ribosomal RNA genes, 13 protein-coding genes, 22 transfer RNA genes, and a D-Loop region. The mitogenome is 16 617 bp in length, with a homology of 50% between the mitogenome of Ujumuqin sheep and that of Texel sheep. The unveiling of the mitochondrial DNA sequence of Ujumuqin sheep will have a significant role to play in the further studies on sheep evolution and domestication.

Mortality and lamb body mass growth in free-ranging domestic sheep - environmental impacts including lethal and non-lethal impacts of predators

The management and recovery of large predator populations in areas where human persecution has driven them to ecological extinction requires a solid understanding of the effects of both predation and food limitation on prey populations. We used 11 yr of data on reported losses among 17.3 million free-ranging sheep Ovis aries in the Norwegian farming industry to elucidate the relative roles of climate, vegetation characteristics, sheep densities, lamb body mass and densities of predators and alternative prey on the number of lambs and ewes lost on summer pastures. We first examined whether predator densities predicted autumn lamb body mass through possible impacts of predators on body growth (non-lethal effects) but found no evidence for such effects in our study system. This might be due to weak anti-predator behavioral responses in domesticated sheep. However, autumn lamb body mass was predicted by both sheep density and winter and spring weather conditions, probably through food availability. Losses of both lambs and ewes were positively and strongly related to the density of Eurasian lynx Lynx lynx, wolverine Gulo gulo and brown bear Ursus arctos. In addition, food availability and spring weather conditions were associated to losses of lambs, while precipitation in May predicted losses of ewes. There was little evidence for interaction effects of predator species on losses, suggesting that most of the effects of the predators were additive to each other. Given the strong effect of predator densities on sheep losses, we conclude that changing livestock husbandry practices towards a system that actively protects sheep and/or active management of predator densities may be necessary to reduce sheep losses where predators are recolonizing.

Molecular detection of Babesia ovis in sheep and ticks using the gene encoding B. ovis surface protein D (BoSPD)

The gene encoding Babesia ovis surface protein D (BoSPD) was cloned from B. ovis cDNA library. This gene encodes a polypeptide chain of 155 amino acids, including a predicted 22 amino acid signal peptide. Sequence analysis of the BoSPD suggested that it is a surface protein with no known domains. BLAST analysis followed by multiple alignments showed four orthologs from other Apicomplexan species and suggested that BoSPD is specific for B. ovis. BoSPD-based PCR was then developed to specifically detect B. ovis in experimentally-infected sheep and Rhipicephalus bursa ticks, as well as in field samples. The PCR enabled detection of B. ovis at a calculated parasitemia of 0.0016% and was shown to be specific for B. ovis. Moreover, the BoSPD PCR allowed detection of prolonged subclinical infection in experimentally-infected lambs and in dissected organs of experimentally-infected ticks. Finally, the PCR was used to detect parasitemia in blood samples from naturally-infected sheep and in R. bursa ticks collected from sheep in an infected flock. These results suggest that the BoSPD gene sequence can be used as a specific and sensitive marker, allowing detection of subclinical parasitemia in sheep and in ticks. Based on its predicted properties, BoSPD may be considered as a candidate for anti-B. ovis vaccine development or a target for anti-B.ovis treatment.

PSOROPTES INFESTATION AND TREATMENT IN AN ISOLATED POPULATION OF BIGHORN SHEEP (OVIS CANADENSIS).

The authors captured bighorn sheep (Ovis canadensis) comprising a small population in the San Bernardino Mountains of California and evaluated the degree of infestation by mites of the genus Psoroptes for each individual. The animals were treated with two novel methods: amitraz-impregnated collars and cyfluthrin-impregnated ear tags and recaptured the following year to evaluate the effect of treatment. The authors compared data on degree of infestation for animals recaptured in the posttreatment year, detected no significant interyear differences in infestation severity scores among animals treated with amitraz or cyfluthrin, and could not detect any differences between treatment types. However, a significant (P<0.10) decreased pattern in severity scores from the beginning to the end of treatments was detected, suggesting a cumulative therapeutic value in repeated annual treatments across the 3-yr period. Additionally, the authors detected a lower median mite severity score between 2000 and a later capture in 2006. These positive outcomes may be the result of previous treatments during 2000-2002, but environmental covariates not accounted for could have been contributing factors. Avermectin drugs with longer release profiles may be a more effective treatment option in this and other small bighorn sheep populations that are compromised with mite infestations.

High occurrence of mitochondrial heteroplasmy in nepalese indigenous sheep (Ovis aries) compared to chinese sheep

Heteroplasmy due to length polymorphism with tandem repeats in mtDNAs within individual was hardly studied in domestic animals. In the present study, we identified intra-individual length variation in the control region of mtDNAs in Nepalese sheep by molecular cloning and sequencing techniques. We observed one to four tandem repeats of a 75-bp nucleotide sequences in the mtDNA control region in 45% of the total Nepalese sheep sampled in contrast to the Chinese sheep, indicating that the heteroplasmy is specific to Nepalese sheep. The high rate of heteroplasmy in Nepalese sheep could be a resultant of the mtDNA mutation and independent segregation at intra-individual level or a strand slippage and mispairing during the replication.

A tale of two markers: Population genetics of colorado rocky mountain bighorn sheep estimated from microsatellite and mitochondrial data

Five native herds of Rocky Mountain bighorn sheep (Ovis canadensis) occupy Rocky Mountain National Park and the immediate surrounding area. One of these herds, the Mummy herd, suffered a significant die-off following a suspected pneumonia outbreak in the mid-1990s with subsequent low population size and low yearling recruitment, as compared to the other 4 herds. To test the hypothesis that the Mummy herd's failure to thrive is due to decreased genetic variation as a result of a genetic bottleneck, we analyzed both microsatellite and mitochondrial data to estimate genetic differentiation, gene flow, and the extent of metapopulation substructure among all 5 herds. Our microsatellite analyses showed no evidence of a recent genetic bottleneck or inbreeding. Our comparisons of overall and pairwise population differentiation (Fst) and effective migration (Nm) from both microsatellite genotypes and mitochondrial haplotypes indicated that low population substructure was being maintained by moderate levels of gene flow among all 5 herds. Effective migration rates were both higher and more uniform among herds for microsatellite genotypes than for mitochondrial haplotypes, which exhibited an asymmetrical pattern among herds. A significant isolation-by-distance relationship for mitochondrial (but not microsatellite) data suggests that gene flow is primarily due to ram migration. Past translocations of sheep into, out of, and among these 5 herds are an important consideration when interpreting these results; however, our data clearly show that all 5 Rocky Mountain bighorn sheep herds have reasonable and equivalent levels of genetic variation. Thus, herd management and restoration efforts should be focused on other factors that might be detrimental to herd health, such as stress, nutritional deficiencies, habitat fragmentation, climactic factors, or disease. © 2015 The Wildlife Society.

The role of hunters in conservation, restoration, and management of North American wild sheep

Wild sheep in North America were abundant and widely distributed prior to European exploration and settlement. By the early twentieth century unregulated hunting, forage competition with domestic livestock, introduced diseases, and human encroachment had dramatically reduced bighorn sheep (Ovis canadensis) numbers and distribution in the western US, southern Canada, and mainland and Baja Peninsula Mexico. The restoration of bighorn sheep has been a remarkable conservation success, as a result of efforts by wildlife and land management agencies, conservation organizations, private landowners and other stakeholders. These efforts have been largely underwritten by pro-hunting conservation organizations.

First molecular isolation of Mycoplasma ovis from small ruminants in North Africa.

Eperythrozoonosis is a small ruminant disease caused by the bacterium Mycoplasma ovis (formerly known as Eperythrozoon ovis). Whilst acute infection in sheep may result in an anaemia and ill thrift syndrome, most animals do not develop clinical signs. Molecular methods were used to compare and evaluate the prevalence of infection with M. ovis in sheep and goats in Tunisia. A total of 739 whole blood samples from 573 sheep and 166 goats were tested for the M. ovis 16S rRNA gene using PCR. The overall prevalence was 6.28% ± 0.019 (36/573). Only sheep were infected with M. ovis (p < 0.001), and the prevalence was significantly higher in central Tunisia (29.2%) compared with other regions (p < 0.05). The prevalence revealed significant differences according to breed and bioclimatic zones (p < 0.001). Furthermore, the prevalence in young sheep (35/330; 10.6%) was higher than in adults (1/243; 0.41%) (p < 0.001). Only sheep of the Barbarine breed were infected, with a prevalence of 11.8% (p < 0.001). This is the first molecular study and genetic characterisation of M. ovis in North African sheep breeds.

Co-occurrence of reintroduced and resident ungulates on a shared winter range in northwestern Canada

For interspecific competition to occur species must use the same limited resources (e.g. food, habitat) and overlap in time and space. Bison (Bison bison) were reintroduced to southwestern Yukon, Canada, where they are sympatric with resident caribou (Rangifer tarandus), moose (Alces americanus) and thinhorn sheep (Ovis dalli). Concerns from local communities regarding potential competition between reintroduced bison and resident ungulates prompted us to test their spatial distribution for co-occurrence. In late-winter, we conducted multiple aerial surveys (n = 1–5) of 12.2 km2 cells (n = 779) to develop a presence–absence matrix (4 species × 779 cells) of the spatial distribution of ungulates. Randomization procedures were used to conduct a null model analysis of co-occurrence. Community-wide null model analysis indicated that community members were neither segregated nor aggregated; rather, their spatial distribution was random because they did not differ from simulated null communities (n = 50,000). Similar analyses conducted on sub-matrices for each species pair also did not find evidence for segregation or aggregation among any species pairs except caribou and sheep, who were spatially segregated. We conclude that the overall potential for competition between reintroduced bison and resident ungulates during late-winter is low, based on spatial overlap. However, further investigations on the potential for competition among other niche dimension axes (e.g. food, habitat use) are recommended. Even though bison are reintroduced, these species had interacted for thousands of years and have probably co-evolved mechanisms to partition resources and co-exist on a shared landscape.

Prenatal Development of Yankasa Sheep (Ovis aries) Kidney: A Histomorphometric Study

Histomorphometric study was conducted on the kidneyof seventeen (17) fetuses of the Yankasa sheep (Ovis aries) collected from the Sokoto metropolitan abattoir, over a period of one month at different gestational ages. The approximate age of the fetuses was estimated from the crown vertebral rump length (CVRL) and samples were categorised into first, second and third trimester. Out of the seventeen (17) fetuses at different gestational age used for the study, 7 (48%) were females while 10 (52%) were males. 6(35%) fetuses belong to first trimester, 5(30%) belong to second trimester and 6(35%) belong to third trimesters of pregnancy respectively. The mean crown vertebrate-rump length (CVRL) ranged from 12.47 ± 1.80 cm at first trimester to 33.79 ±1.52 cm at third trimester. Histological observation shows that the kidney appeared to have two zones via cortex and medulla right from first to third trimester. The development of renal tissues were found to be in succession, from the stage of mesenchyme cells, developing glomerulusand finally to fully developed glomerulus with advancement of gestational age among the three groups. The duct system also followed the same trend of development from immature to matured duct system. The cortex of the first trimester kidney was found to have numerous mesenchymal cells and connective tissues with few developing glomerulus. At second trimester few fully developed glomerulus were found, moderate number of mesenchyme cells and immature developing duct system. Numerous developed glomerulus and matured duct system with moderate developing glomerulus and connective tissue were seen at third trimester. The medulla at first trimester shows only various types of connective tissue (collagen, reticular and elastic) fibers and mesenchyme cells. At second trimester the medulla was found to have numerous developing collecting ducts, few developed collecting ducts and few mesenchyme cells. Developed collecting ducts were predominant in the medulla at third trimester with few mesenchyme cells. The histological differentiation of the Yankasa sheep kidney is similar to that of ovine, bovine, equine, Llama, and guanaco but differs from that of the feline, canine and porcine. Meanwhile, considering the histological features observed in the study, the Yankasa sheep kidney may become fully matured and functional at post-natal age.

Differentiated evolutionary relationships among chordates from comparative alignments of multiple sequences of MyoD and MyoG myogenic regulatory factors.

MyoD and MyoG are transcription factors that have essential roles in myogenic lineage determination and muscle differentiation. The purpose of this study was to compare multiple amino acid sequences of myogenic regulatory proteins to infer evolutionary relationships among chordates. Protein sequences from Mus musculus (P10085 and P12979), human Homo sapiens (P15172 and P15173), bovine Bos taurus (Q7YS82 and Q7YS81), wild pig Sus scrofa (P49811 and P49812), quail Coturnix coturnix (P21572 and P34060), chicken Gallus gallus (P16075 and P17920), rat Rattus norvegicus (Q02346 and P20428), domestic water buffalo Bubalus bubalis (D2SP11 and A7L034), and sheep Ovis aries (Q90477 and D3YKV7) were searched from a non-redundant protein sequence database UniProtKB/Swiss-Prot, and subsequently analyzed using the Mega6.0 software. MyoD evolutionary analyses revealed the presence of three main clusters with all mammals branched in one cluster, members of the order Rodentia (mouse and rat) in a second branch linked to the first, and birds of the order Galliformes (chicken and quail) remaining isolated in a third. MyoG evolutionary analyses aligned sequences in two main clusters, all mammalian specimens grouped in different sub-branches, and birds clustered in a second branch. These analyses suggest that the evolution of MyoD and MyoG was driven by different pathways.

Analysis of phenotypic change in relation to climatic drivers in a population of Soay sheep Ovis aries

Climatic change has frequently been identified as a key driver of change in biological communities. These changes can take the form of alterations to population dynamics, phenotypic characters, genetics and the life history of organisms and can have impacts on entire ecosystems. This study presents a novel investigation of how changes in a large scale climatic index, the North Atlantic Oscillation (NAO) can influence population dynamics and phenotypic characters in a population of ungulates. We use an integral projection model combined with actual climate change predictions to project future body size distributions for a population of Soay sheep Ovis aries. The climate change predictions used to direct our model projections were taken from published results of climate models, covering a range of different emissions scenarios. Our model results showed that for positive changes in the mean NAO large population declines occurred simultaneously with increases in mean body weight. The exact direction and magnitude of changes to population dynamics and character distributions were dependent on the greenhouse gas emissions scenario and model used to predict the NAO. This study has demonstrated how integral projection models can use outputs of climate models to direct projections of population dynamics and phenotypic character distributions. This approach allows the results of this study to be placed within current climate change research. The nature of integral projection models means that this methodology can be easily applied to other populations. The model can also be easily updated when new climate change predictions become available, making it a useful tool for understanding potential population level responses to climatic change.SynthesisUnderstanding how changes in climate affect biological communities is a key component in predicting the future form of populations. Utilising a novel approach that incorporates climatic drivers (in this instance the winter North Atlantic Oscillation) into an integral projection model framework, we predict future Soay sheep dynamics under specific climate change scenarios. Tracking quantitative trait distributions and life history metrics, our results predict declining population size and increasing body weight for an increasingly positive winter North Atlantic Oscillation index, as predicted by climate models. This has important implications for future wildlife management strategies and linking demographic responses to climate change.

Grazing by sheep Ovis aries reduces island populations of water voles Arvicola amphibius

The population of water voles Arvicola amphibius was surveyed on 21 islands in the Solvær archipelago, northern Norway, in August 2012; 11 islands with semi-wild domestic sheep Ovis aries and 10 islands without sheep. Signs from water voles are very easy to detect and were used as a measure of the population (on a scale 0-10), and the numbers of sheep were counted. The ranking of signs on islands with and without sheep was compared, and a significant difference was found. Islands with sheep had, with one exception, only very small and fragmented populations of water voles, the one exception being a fairly large Carex swamp that was not grazed by the sheep and where a moderate-sized population of voles was found. Islands without sheep had much larger populations of water voles, giving a ranking about four times higher. One reason for the devastating effect of sheep on water voles is probably the fact that the sheep are living year-round on these islands with no supplemental food.

Technical note: Protozoa-specific antibodies raised in sheep plasma bind to their target protozoa in the rumen.

Binding of IgG antibodies to Entodinium spp. in the rumen of sheep (Ovis aries) was investigated by adding IgG, purified from plasma, directly into the rumen. Plasma IgG was sourced from sheep that had or had not been immunized with a vaccine containing whole fixed Entodinium spp. cells. Ruminal fluid was sampled approximately 2 h after each antibody dosing. Binding of protozoa by a specific antibody was detected using an indirect fluorescent antibody test. An antibody titer in the ruminal fluid was determined by ELISA, and the concentration of ruminal fluid ammonia-N and ruminal pH were also determined. Entodinium spp. and total protozoa from IgG-infused sheep were enumerated by microscopic counts. Two-hourly additions of IgG maintained a low antibody titer in the rumen for 12 h and the binding of the antibody to the rumen protozoa was demonstrated. Increased ammonia-N concentrations and altered ruminal fluid pH patterns indicated that additional fermentation of protein was occurring in the rumen after addition of IgG. No reduction in numbers of Entodinium spp. was observed (P>0.05). Although binding of antibodies to protozoa has been demonstrated in the rumen, it is unclear how much cell death occurred. On the balance of probability, it would appear that the antibody was degraded or partially degraded, and the impact of this on protozoal populations and the measurement of a specific titer is also unclear.