Natural grazing by horses and cattle promotes bird diversity in a restored European alluvial grassland.

Context: A challenge in grassland conservation is to maintain both the openness and the heterogeneity of the habitat to support the diversity of their animal communities, including birds-a taxon that is known to be sensitive to disturbance. An increasingly used management tool in European grassland conservation, especially in rewilding projects, is grazing by large herbivores such as horses and cattle. These grazers are believed to create and maintain patchy landscapes that promote diversity and richness of other species, but their influence on birds is often debated by conservationists, who raise concerns about the impact of disturbance by the grazers. Objectives: Our aim was to examine the relationship between the abundance and species richness of birds across four foraging guilds and the area utilization patterns of Highland cattle and Konik horses in an alluvial grassland in France. We also aimed to examine the influence of land cover and season on the spatial distribution, including abundance and species richness, of different bird guilds present in the grazed area. Methods: We used GPS-collars on all grazers and recorded their positions on an hourly basis over a study period of 1.5 years, assessing patterns of area usage. We counted birds weekly along three transects to describe their distribution within the grazed area and carried out land-cover surveys to describe the habitat. To assess how species richness and abundance of birds of different guilds were related to grazer density, season, and habitat characteristics, we used GAMM models in a spatially explicit framework. We also compared bird numbers at our main study site with a nearby non-grazed control area. Results: The number of birds in the grazed area was about twice the number in the non-grazed control area. Within the grazed area, the abundance of open-area foraging birds increased with increasing grazer density. The number of woodland-foraging birds was also positively correlated with grazer density but less so than open-area foraging birds. The number of individuals in the aerial and wetland bird guilds was not correlated with the density of grazers. Most bird species and individuals were observed on open landscapes scattered with woody patches and waterbodies, and on areas with moderate grazer density. Conclusions: Low-intensity grazing represents a potentially important management tool in creating heterogeneity in alluvial grasslands, thereby promoting suitable habitat for a diverse assemblage of bird species.

A 3D geometric morphometric analysis of the bovid distal humerus, with special reference to Rusingoryx atopocranion (Pleistocene, Eastern Africa).

The family Bovidae [Mammalia: Artiodactyla] is speciose and has extant representatives on every continent, forming key components of mammal communities. For these reasons, bovids are ideal candidates for studies of ecomorphology. In particular, the morphology of the bovid humerus has been identified as highly related to functional variables such as body mass and habitat. This study investigates the functional morphology of the bovid distal humerus in isolation due to its increased likelihood of preservation in the fossil record, and the resulting opportunity for a better understanding of the ecomorphology of extinct bovids. A landmark scheme of 30 landmarks was used to capture the 3D distal humerus morphology in 111 extant bovid specimens. We find that the distal humerus has identifiable morphologies associated with body mass, habitat preference and tribe affiliation and that some characteristics are shared between high body mass bovids and those living on hard, flat terrain which is likely due to the high stress on the bone in both cases. We directly apply our findings regarding extant bovids to the extinct alcelaphine bovid, Rusingoryx atopocranion from the mid to late Pleistocene (>33-45 ka) Lake Victoria region of Kenya. This species is known for some peculiar morphologies including a domed cranium with hollow nasal crests, and having small hooves for a bovid of its size. Another interesting aspect of Rusingoryx's skeletal morphology which has not been addressed is an unusual protrusion on the lateral epicondyle of the distal humerus. Despite considerable individual variation in the Rusingoryx specimens, we find evidence to support its historical assignment to the tribe Alcelaphini, and that it likely preferred open grassland habitats, which is consistent with independent reconstructions of the palaeoenvironment. We also provide the most accurate body mass estimate for Rusingoryx to date, based on distal humerus centroid size. Overall, we are able to conclude that the distal humerus in extant bovids is highly informative regarding body mass, habitat preference and tribe, and that this can be applied directly to a fossil taxon with promising results.

Morphological Differences between Sheep and Goat Calcanea Using Two-Dimensional Geometric Morphometrics.

The distinction between bones of sheep and bones of goats is a difficult issue in zooarchaeology. Several studies undertaken in the past to facilitate this task have relied upon both qualitative criteria and osteometry. Geometric morphometrics has proved to be a powerful tool to evaluate morphological differences in a rigorous and detailed manner. This study aims to analyse variations in the morphology of the calcaneum among sheep and goats based upon two-dimensional geometric morphometrics (GM). Twenty landmarks were selected on the surfaces of 79 calcanea (47 sheep and 32 goats) to calculate the principal components of shape variations among these specimens. Clear interspecific differences in the morphology of this bone were extracted. Most are located on the calcaneal tuber and neck, the sustentacular tali region, the articular surfaces of both the malleolus and the cubonavicular. Furthermore, the use of GM methods has enabled us to assess small but significant amounts of geometric variation that are difficult to measure using traditional morphometric techniques. They provide a new and useful perspective to what is already known in the published literature. Our results shed new light upon the possibility of the existence of qualitative features that may help to distinguish caprine breeds.

Influence of ovarian follicular wave synchronization and single-dose eCG superstimulation on oocyte collection and in vitro embryo production in bison during the ovulatory and anovulatory seasons.

In an effort to develop an effective, minimum-handling protocol for the conservation of wood bison, the present study was designed to determine the effects of ovarian synchronization and superstimulation on cumulus oocyte complex (COC) collection and in vitro embryo production in wood bison during the ovulatory (Exp. 1) and anovulatory seasons (Exp. 2). We tested the hypotheses that COC collection and in vitro embryo production are 1) greater after follicular wave synchronization than at random stages of the follicular wave, 2) repeatable within individuals, 3) greater after ovarian superstimulation with a single dose of eCG than without treatment, and 4) greater during the anovulatory season than the ovulatory season. In Exp. 1, ultrasound-guided COC collection was performed on Day -1 in wood bison to induce follicular wave emergence the following day (Day = 0). Immediately after the COC collection on Day -1, bison were given a single im dose of 2500 IU eCG or saline (n = 6 per group). Subsequent COC collections were on Days 4 and 9. A similar design was used in Exp. 2, with an additional treatment group given 5000 IU eCG (n = 8 per group). In Exp. 1, compared to the saline-treated group, a single dose of 2500 IU eCG resulted in a greater number of ≥8 mm follicles at the time of the Day 4 COC collection (P = 0.03), but not at the Day 9. In Exp. 2, treatment with 5000 IU eCG resulted in a greater number of ≥8 mm follicles than 2500 IU eCG or the saline treatment (37.5 ± 6.9, 17.5 ± 2.0, 16.9 ± 2.0; P = 0.01, respectively). Although the number of embryos produced/COC submitted to IVM was not different among groups (mean = 18.6%), treatment with 5000 IU eCG produced more than twice as many embryos per bison as unstimulated bison (0.8 vs 1.9). In summary, embryo production rates were higher from COC collected subsequent to follicular wave synchronization vs random stages of the wave, and ovarian superstimulation with eCG resulted in a dose-related increase in the number of ≥8 mm follicles, COC collected, and embryos produced. Repeated COC collections after successive wave synchronization resulted in similar follicular counts and embryo production rates within individuals, and the greatest number of follicles aspirated, COC collected, and embryos produced was in the anovulatory season. We conclude that the minimum-handling COC collection protocols in the present study are effective and provide realistic options for embryo production in wild bison.

Teeth out of proportion: Smaller horse and cattle breeds have comparatively larger teeth.

There are different descriptions of allometric relationships between important components of the mammalian skull. Craniofacial evolutionary allometry describes a pattern of increasing facial cranium in larger skulls. Another body of literature describes disproportionately larger teeth in smaller species or specimens, matching anecdotal observations with dental problems in dwarf breeds whose teeth appear "too large for their skulls." We test the scaling of tooth row length with body size and skull length in a data set comprising 114 domestic horses (representing 40 breeds) and in another data set of 316 domestic cattle (of >60 breeds). We demonstrate that smaller skulls have a relatively longer tooth row in both horses and cattle; larger specimens have relatively shorter tooth rows. Whereas in horses, larger skulls have a relatively longer diastema, the distance of the mesial maxillary premolar to the premaxilla was proportional to cranium length in cattle. While the reasons for these patterns remain to be detected, they support the hypothesis that tooth size might be less "evolvable," in terms of time required for changes, than body size. The pattern may affect (i) the selective breeding for dwarf breeds by setting minimum constraints for skull size, as described previously for domestic horses with the same data set; (ii) the susceptibility of small breeds for dental problems; and (iii) differences in chewing efficiency between breeds of different sizes. The findings support the existing concept that scaling of tooth to body size across taxa becomes more isometric the longer these taxa are separated in evolutionary time.

Do bovids evolve hindquarter markings for anti-predation?

Conspicuous coloration in animals serves many functions such as anti-predation. Anti-predation strategies include motion dazzle and flash behavior. Motion dazzle markings can reduce the probability of being preyed on because the predators misjudge their movement. In flash behavior, prey demonstrate conspicuous cue while fleeing; the predators follow them; however, the prey hide their markings and the predators assume that the prey has vanished. To investigate whether bovids use conspicuous hindquarter markings as an anti-predatory behavior, we undertook phylogenetically controlled analyses to explore under what physiological characteristics and environmental factors bovids might have this color pattern. The results suggested that rump patches and tail markings were more prevalent in bovids living in larger-sized groups, which supports the hypothesis of intraspecific communication. Moreover, we observed the occurrence of conspicuous white hindquarter markings in bovids having smaller body size and living in larger groups, suggesting a motion dazzle function. However, the feature of facultative exposing color patterns (flash markings) was not associated with body size, which was inconsistent with predictions and implied that bovids may not adopt this as an anti-predator strategy. It was concluded that species in bovids with conspicuous white hindquarter markings adopt motion dazzle as an anti-predation strategy while fleeing and escaping from being prey on.

Case Report: Complex Congenital Brain Anomaly in a BBxHF Calf-Clinical Signs, Magnetic Resonance Imaging, and Pathological Findings.

This case report describes the clinical signs, magnetic resonance imaging (MRI) findings and associated (histo)pathological findings in a crossbred Belgian Blue calf with congenital complex brain anomaly. The calf was presented with non-progressive signs (including cerebellar ataxia) since it was born, suggestive of a multifocal intracranial lesion. A congenital anomaly was suspected and after hematology, biochemistry, serology, and cerebrospinal fluid analysis, a magnetic resonance imaging study was performed. The following suspected abnormalities were the principal changes identified: severe hydrocephalus, porencephaly, suspected partial corpus callosum agenesis (CCA), and increased fluid signal between the folia of the cerebellum. Post-mortem examination predominately reflected the MRI findings. The origin for these malformations could not be identified and there was no evidence of a causative infectious agent. Corpus callosum abnormalities have been reported in bovids before and have been linked to bovine viral diarrhea virus (BVDV) infections, as have several other central nervous system anomalies in this species. In this case, BVDV was deemed an unlikely causative agent based on serology test results and lack of typical histopathological signs. The etiology of the congenital anomaly present in this bovine calf remains unknown.

Diversity and Paleodemography of the Addax (Addax nasomaculatus), a Saharan Antelope on the Verge of Extinction.

Since the 19th century, the addax (Addax nasomaculatus) has lost approximately 99% of its former range. Along with its close relatives, the blue antelope (Hippotragus leucophaeus) and the scimitar-horned oryx (Oryx dammah), the addax may be the third large African mammal species to go extinct in the wild in recent times. Despite this, the evolutionary history of this critically endangered species remains virtually unknown. To gain insight into the population history of the addax, we used hybridization capture to generate ten complete mitochondrial genomes from historical samples and assembled a nuclear genome. We found that both mitochondrial and nuclear diversity are low compared to other African bovids. Analysis of mitochondrial genomes revealed a most recent common ancestor ~32 kya (95% CI 11-58 kya) and weak phylogeographic structure, indicating that the addax likely existed as a highly mobile, panmictic population across its Sahelo-Saharan range in the past. PSMC analysis revealed a continuous decline in effective population size since ~2 Ma, with short intermediate increases at ~500 and ~44 kya. Our results suggest that the addax went through a major bottleneck in the Late Pleistocene, remaining at low population size prior to the human disturbances of the last few centuries.

Protein Electrophoresis and Haptoglobin Values for Captive Bongo (Tragelaphus eurycerus).

Serum samples collected from 37 clinically normal bongo (Tragelaphus eurycerus) and 13 abnormal bongo were tested using assays for acute-phase proteins (APPs) and by protein electrophoresis. Abnormal bongo samples (n = 27) had significantly higher levels of fibrinogen (FIB) (p < 0.001) and trending but not significantly increased haptoglobin (HP) (p = 0.07) vs. samples from normal bongo (n = 37). There were no significant differences in values for total white blood cell counts or for any of the fractions determined by protein electrophoresis. Clinically normal female bongo (n = 19) had significantly lower levels of FIB than normal males (n = 18) (p = 0.014), and this observation was also made with samples from the clinically abnormal group (p = 0.004). Many weak to moderate significant correlations were observed with increasing age, including increased globulins, FIB, and HP and decreased albumin-to-globulin (A/G) ratio and albumin. In clinical cases reviewed in this study, mild HP changes categorized this reactant as a minor APP, which contrasts with the major APP classification of HP in the related species of the cow. The preliminary data indicate that the quantitation of these APPs may offer value in assessing inflammation in this species, but additional studies are needed.

The detection of Schistosoma bovis in livestock on Pemba Island, Zanzibar: A preliminary study.

Schistosoma bovis is a parasitic trematode of ungulates transmitted by freshwater snails in Sub-Saharan Africa causing bovine intestinal schistosomiasis that leads to chronic morbidity and significant agricultural economic losses. The recently reported occurrence of Bulinus globosus infected with S. bovis for the first time on Pemba Island (Zanzibar, United Republic of Tanzania) is a cause of concern for livestock/wildlife health and complicates the surveillance of Schistosoma haematobium. To confirm that local cattle are infected with S. bovis, fresh faecal samples were collected from six adult cows surrounding two schistosomiasis transmission sites in Kinyasini, Pemba Island. Schistosome eggs were concentrated, egg hatching stimulated and miracidia were individually captured and identified by analysis of the partial mitochondrial cytochrome c oxidase subunit 1 (cox1) and the partial nuclear internal transcribed spacer region (ITS1+5.8S+ITS2). Two S. bovis miracidia were collected from one faecal sample with two cox1 haplotypes, one matching cox1 data obtained from S. bovis cercariae, collected previously at the same site in Pemba, the other matching S. bovis cox1 data originating from coastal Tanzania. The findings conclude that S. bovis transmission has been established on Pemba Island and is likely to have been imported through livestock trade with East Africa. Increasing the sensitivity of non-invasive diagnostics for bovine schistosomiasis, together with wider sampling, will enable a better assessment on the epidemiology of S. bovis on Pemba Island.

Systematic Ancient DNA Species Identification Fails to Find Late Holocene Domesticated Cattle in Southern Africa.

Establishing robust temporal control of the arrival of domesticated stock and the associated husbandry skills and lifeways in Southern Africa remains frustrated by the osteological similarities between domestic stock and wild endemic fauna. We report the results of a systematic ancient DNA survey of appropriately sized bovid remains from Later Stone Age deposits in four South African archaeological sites. We show that none of the tested remains originated in domesticated cattle. The precise date of arrival of domestic cattle in the region awaits further study, although we also report new radiocarbon determinations which further refine the local chronology.

Differential roles of the right and left brain hemispheres in the social interactions of a free-ranging ungulate.

Despite the abundant empirical evidence on lateralized social behaviours, a clear understanding of the relative roles of two brain hemispheres in social processing is still lacking. This study investigated visual lateralization in social interactions of free-ranging European bison (Bison bonasus). The bison were more likely to display aggressive responses (such as fight and side hit), when they viewed the conspecific with the right visual field, implicating the left brain hemisphere. In contrast, the responses associated with positive social interactions (female-to-calf bonding, calf-to-female approach, suckling) or aggression inhibition (fight termination) occurred more likely when the left visual field was in use, indicating the right hemisphere advantage. The results do not support either assumptions of right-hemisphere dominance for control of various social functions or hypotheses about simple positive (approach) versus negative (withdrawal) distinction between the hemispheric roles. The discrepancy between the studies suggests that in animals, the relative roles of the hemispheres in social processing may be determined by a fine balance of emotions and motivations associated with the particular social reaction difficult to categorize for a human investigator. Our findings highlight the involvement of both brain hemispheres in the control of social behaviour.

Bovid mortality patterns from Kanjera South, Homa Peninsula, Kenya and FLK-Zinj, Olduvai Gorge, Tanzania: Evidence for habitat mediated variability in Oldowan hominin hunting and scavenging behavior.

The archaeological record has documented Oldowan hominin occupation of habitats ranging from open grasslands to riparian forest by 2.0 Ma. Despite this we have a poor understanding of whether hominin foraging behavior varied in different environmental settings. We compared bovid mortality profiles from the two largest Oldowan zooarchaeological samples, one from a grassland (Excavation 1, Kanjera South, Kenya) and another from a woodland (FLK Zinj, Olduvai Gorge, Tanzania) with bovid mortality samples created by African carnivores in different habitats. Kanjera hominins frequently had early access, likely through hunting, to small (size 1 ≤ 23 kg and size 2 = 24-112 kg) juvenile bovids, creating a mortality pattern similar to that created by grassland dwelling carnivores. Kanjera hominins had more mixed access to large (size 3 = 113-340 kg), often juvenile, bovids and frequently scavenged heads. In contrast, previous work has shown that the few small bovids at FLK-Zinj were predominantly older individuals. Prime adults dominated the FLK-Zinj large bovid sample, leading to a mortality pattern similar to that created by carnivores occupying more closed habitats. Variation in bovid body size and mortality profiles between these archaeological assemblages may reflect the challenges of acquiring fauna in open versus closed habitats with a simple hunting toolkit. The heterogeneous woodland habitat of FLK-Zinj would have provided more opportunities to ambush prey, whereas on grasslands with more limited concealment opportunities Kanjera hominins focused their efforts on vulnerable juvenile prey, some likely acquired after short chases.

A Novel Orthohepadnavirus Identified in a Dead Maxwell's Duiker (Philantomba maxwellii) in Taï National Park, Côte d'Ivoire.

New technologies enable viral discovery in a diversity of hosts, providing insights into viral evolution. We used one such approach, the virome capture sequencing for vertebrate viruses (VirCapSeq-VERT) platform, on 21 samples originating from six dead Maxwell's duikers (Philantomba maxwellii) from Taï National Park, Côte d'Ivoire. We detected the presence of an orthohepadnavirus in one animal and characterized its 3128 bp genome. The highest viral copy numbers were detected in the spleen, followed by the lung, blood, and liver, with the lowest copy numbers in the kidney and heart; the virus was not detected in the jejunum. Viral copy numbers in the blood were in the range known from humans with active chronic infections leading to liver histolytic damage, suggesting this virus could be pathogenic in duikers, though many orthohepadnaviruses appear to be apathogenic in other hosts, precluding a formal test of this hypothesis. The virus was not detected in 29 other dead duiker samples from the Côte d'Ivoire and Central African Republic, suggesting either a spillover event or a low prevalence in these populations. Phylogenetic analysis placed the virus as a divergent member of the mammalian clade of orthohepadnaviruses, though its relationship to other orthohepadnaviruses remains uncertain. This represents the first orthohepadnavirus described in an artiodactyl. We have tentatively named this new member of the genus Orthohepadnavirus (family Hepadnaviridae), Taï Forest hepadnavirus. Further studies are needed to determine whether it, or some close relatives, are present in a broader range of artiodactyls, including livestock.

PREVALENCE OF PARELAPHOSTRONGYLUS ANDERSONI IN WHITE-TAILED DEER, OTHER CERVIDS, AND BOVIDS IN NORTHERN FLORIDA.

Parelaphostrongylus andersoni, the muscleworm, commonly infects white-tailed deer (Odocoileus virginianus) and also infects caribou (Rangifer tarandus [R.t.] groenlanicus, R.t. grantii, R.t. tarandus, and R.t. caribou). Heavy infection with P. andersoni leads to weakness in the hindquarters, abnormal gait, and pulmonary lesions. The geographical range and full host spectrum of this parasite are not fully known. This study aims to understand host specificity better, especially in nonnative cervids and bovids. This study involved the collection of 140 fecal samples from native and nonnative cervid and bovid species, and 34 snail specimens. With the use of real-time PCR, we found 4/47 (8.5%) O. virginianus fecal samples were positive for P. andersoni. No previously undocumented species of cervids or bovids were found to be infected. Further research is warranted to understand P. andersoni range, host distribution, and potential impact on host health.

Dairy production practices and associated risks for bovine vaccinia exposure in cattle, Brazil.

A cross-sectional serosurvey was performed to identify environmental features or practices of dairy farms associated with risk for exposure to vaccinia-like viruses in dairy cattle in Brazil. Sera from 103 cows from 18 farms in Minas Gerais state were examined for Orthopoxvirus-neutralizing antibodies. A database of 243 binary or multiple-selection categorical variables regarding the physical features and surrounding ecology of each property was obtained. Thirteen of 46 presumptive predictor variables were found to be significantly associated with Orthopoxvirus serostatus by univariate logistic regression methods. Use of teat sanitizer and having felids on the property were independently associated with virus exposure by multivariable analysis. Rodents have long been suspected of serving as maintenance reservoirs for vaccinia-like viruses in Brazil. Therefore, domestic felids are not only effective predators of small rodent pests, but also their urine can serve as a deterrent to rodent habitation in buildings such as stables and barns. These results corroborate previous evidence of the high significance of rodents in the Vaccinia virus transmission cycle, and they also raise questions regarding the common use of teat sanitizers in dairy production areas.

Exploring morphological generality in the Old World monkey postcranium using an ecomorphological framework.

Nearly all primates are ecologically dependent on trees, but they are nonetheless found in an enormous range of habitats, from highly xeric environments to dense rainforest. Most primates have a relatively 'generalised' skeleton, enabling locomotor flexibility and facilitating other crucial functions, such as manual foraging and grooming. This paper explores the associations between habitat, locomotion and morphology in the forelimbs of cercopithecids (Old World monkeys), contextualising their skeletal ecomorphological patterns with those of other mammals, and complementing functional morphological analyses with phylogenetic comparative techniques. The ecomorphological signals present in the generalised primate postcranium, and how an ancestral arboreal 'bauplan' might be modified to incorporate terrestriality or exploit distinct arboreal substrates, are investigated. Analysis of ecomorphological variation in guenons indicates that terrestrial Chlorocebus species retain core elements of a general guenon form, with modifications for terrestriality that vary by species. Adaptation to different modes of arboreality has also occurred in Cercopithecus. The considerable morphological similarity in the guenons sampled emphasises the importance of generality in the primate postcranium - much forelimb variation appears to have emerged stochastically, with a smaller number of traits having a strong functional signal. Analysis of a broader sample of cercopithecids and comparison with felids, suids and bovids indicates that although the cercopithecid humerus has functional morphological signals that enable specimens to be assigned with a reasonable degree of certainty to habitat groups, there is considerable overlap in the specimens assigned to each habitat group. This probably reflects ecological dependence on trees, even in predominantly terrestrial species, as well as the multiple functions of the forelimb and, in some cases, wide geographic distributions that promote intraspecific variation. The use of phylogenetic correction reduced the discriminatory power of the models, indicating that, like allometry, phylogeny contains important ecomorphological information, and should not necessarily be factored out of analyses.

Beyond mice and men: environmental change, immunity and infections in wild ungulates.

In the face of rapid environmental change, anticipating shifts in microparasite and macroparasite dynamics, including emergence events, is an enormous challenge. We argue that immunological studies in natural populations are pivotal to meeting this challenge: many components of environmental change--shifts in biotic assemblages, altered climate patterns and reduced environmental predictability--may affect host immunity. We suggest that wild ungulates can serve as model systems aiding the discovery of immunological mechanisms that link environmental change with parasite transmission dynamics. Our review of eco-immunological studies in wild ungulates reveals progress in understanding how co-infections affect immunity and parasite transmission and how environmental and genetic factors interact to shape immunity. Changes in bioavailability of micronutrients have been linked to immunity and health in wild ungulates. Although physiological stress in response to environmental change has been assessed, downstream effects on immunity have not been studied. Moreover, the taxonomic range of ungulates studied is limited to bovids (bighorn sheep, Soay sheep, chamois, musk oxen, bison, African buffalo) and a few cervids (red deer, black-tailed deer). We discuss areas where future studies in ungulates could lead to significant contributions in understanding the patterns of immunity and infection in natural populations and across species.

Bovine leukemia virus DNA in human breast tissue.

Bovine leukemia virus (BLV), a deltaretrovirus, causes B-cell leukemia/lymphoma in cattle and is prevalent in herds globally. A previous finding of antibodies against BLV in humans led us to examine the possibility of human infection with BLV. We focused on breast tissue because, in cattle, BLV DNA and protein have been found to be more abundant in mammary epithelium than in lymphocytes. In human breast tissue specimens, we identified BLV DNA by using nested liquid-phase PCR and DNA sequencing. Variations from the bovine reference sequence were infrequent and limited to base substitutions. In situ PCR and immunohistochemical testing localized BLV to the secretory epithelium of the breast. Our finding of BLV in human tissues indicates a risk for the acquisition and proliferation of this virus in humans. Further research is needed to determine whether BLV may play a direct role in human disease.

Microstructure and mechanical properties of horns derived from three domestic bovines.

The microstructure and mechanical properties of horns derived from three domestic bovines (buffalo, cattle and sheep) were examined. The effects of water content, sampling position and orientation of three bovid horns on mechanical properties were systematically investigated by uniaxial tension and micron indentation tests. Meanwhile, the material composition and metal element contents were determined by Raman spectroscopy and elemental analysis respectively, and the microstructures of the horns were measured by scanning electron microscopy (SEM). Results show that the mechanical properties of horns have negative correlation with water contents and depend on sampling position and orientation. The spatial variations of the mechanical properties in horns are attributed to the different keratinization degrees in the proximal, middle and distal parts. And the mechanical properties of horns in the longitudinal direction are better than those in transverse. Among the three kinds of horns, the mechanical properties of buffalo horn are the best, followed by cattle horn, and those in sheep horn are the worst. This is due to the differences in material composition, metal element, and the microstructures of the horns. But the mechanical properties of buffalo horns are not dependent on the source of the buffalo. Therefore, regular engineered buffalo keratinous materials with standard mechanical properties can be obtained from different buffalo horns by using proper preparation methods.