Identification and characterisation of Gamma-herpesviruses in zoo artiodactyla

Background: Viruses within the γ-herpesviruses subfamily include the causative agents of Malignant Catarrhal Fever (MCF) in several species of the order Artiodactyla. MCF is a usually fatal lymphoproliferative disease affecting non-adapted host species. In adapted host species these viruses become latent and recrudesce and transmit during times of stress or immunosuppression. The undetected presence of MCF-causing viruses (MCFVs) is a risk to non-adapted hosts, especially within non-sympatric zoological collections. This study investigated the presence of MCFVs in six different zoological collections in the UK, to evaluate the presence of subclinical/latent MCFVs in carrier animals. Methods: One-hundred and thirty eight samples belonging to 54 different species of Artiodactyla were tested by Consensus Pan-herpes PCR. The positive samples were sequenced and subjected to phylogenetic analyses to understand their own evolutionary relationships and those with their hosts. Results: Twenty-five samples from 18 different species tested positive. All viruses but one clustered in the γ-herpesvirus family and within the Macavirus as well as the non-Macavirus groups (caprinae and alcelaphinae/hippotraginae clusters, respectively). A strong association between virus and host species was evident in the Macavirus group and clustering within the caprinae group indicated potential pathogenicity. Conclusion: This study shows the presence of pathogenic and non-pathogenic MCFVs, as well as other γ-herpesviruses, in Artiodactyla species of conservation importance and allowed the identification of new herpesviruses in some non-adapted species

Comparative use of four different marker systems for the estimation of digestibility and low food intake in a group of captive giraffes (giraffa camelopardalis)

In a feeding trial with four captive giraffes, nutrient digestibility was determined using four different marker systems. Although cobalt-ethylenediaminetetraacetic acid proved to have no utility as a digestibility marker in this study, reasonable values could be obtained using C36 n-alkane, acid detergent lignin, and acid insoluble ash as markers. A comparison of methods and literature data suggests that the values derived from the C36 n-alkane assay are the most reliable absolute values. Apparent digestibility ranges thus determined were 63.5-74.3% for dry matter, 73.4-82.4% for crude protein, 49.9-62.2% for neutral detergent fiber, and 49.7-63.7% for acid detergent fiber. However, digestibility data gained by the ADL method provided the most stringent inter-individual comparisons. It is concluded that both alkanes and lignin can be used for giraffe digestibility studies. These captive giraffes ingested a smaller quantity of food than has been reported for other giraffes from both the wild and other zoos. Energetic calculations showed that these animals might be on the brink of an energy deficit. A similar situation has been described at least once before in captive giraffes, and the results are of direct relevance to the peracute mortality syndrome, a condition of captive giraffes in which severe depletion of body fat stores occurs. Reasons for the seemingly low food intake could not be elucidated, but observations suggested that these giraffes were ready to ingest more if more palatable or suitable food was offered. Monitoring food intake in other giraffe groups and designing a diet that is both palatable and nutritious are important objectives of captive giraffe management

Digestive anatomy, physiology, resting metabolism and methane production of captive maras (Dolichotis patagonum)

The digestive physiology of maras (Dolichotis patagonum) has not been investigated in detail. Maras have a particular limb anatomy facilitating a unique cursoriality among rodents. This may also have led to additional adaptations such as a reduced volume of the gastrointestinal tract. We performed macroanatomical measurements of, and determined mean particle size along, the digestive tract of 10 semi-free-ranging animals (7.04 ± 1.05 kg). Additionally, we measured CH4 emission in five captive animals (7.67 ± 0.98 kg) fed a diet of pelleted lucerne, and measured food intake, digestibility, and digesta mean retention time (MRT) of a solute and three particle markers (fed at < 2, 10 and 20 mm particle size). The digestive tract contents represented 11.1 ± 1.4% of body mass, similar to other mammals and rodents, and there was slight indication of selective small particle retention in the caecum. Secondary peaks in marker elimination patterns suggested the possibility of caecotrophy. The MRTs were 15.4 h for the solute and 13.6 h, 13.3 h and 13.3 h for the three particle markers, respectively. At a dry matter intake of 61 ± 12 g kg body mass-0.75 d−1, the maras digested organic matter and neutral detergent fibre to 48 ± 8% and 34 ± 10%, respectively, which is in the lower range of results from horses fed on a diet with a similar fibre content. The respiratory quotient (CO2/O2) was 0.93 ± 0.03, the resting metabolic rate 346 ± 35 kJ kg body mass-0.75 d−1, and CH4 emissions averaged at 3.85 ± 0.47 L d−1 and 14.5 ± 5.2 L per kg dry matter intake; this at a CH4/CO2 ratio of 0.042 ± 0.004. Thus, the methane yield was of a magnitude expected for a hypothetical ruminant of this body mass. The results are consistent with the general understanding of hystricomorph rodent digestive physiology, including caecotrophy, but do not indicate a reduction of digestive capacity to support cursoriality. These results, and those obtained from other hystricomorph rodents, suggest that CH4 production may be more prominent in rodents than previously thought

Digestive anatomy, physiology, resting metabolism and methane production of captive maras (Dolichotis patagonum)

ISSN:1095-6433ISSN:0300-9629ISSN:1531-433

Histological sections of growth anomalies (GA) only identified in blister-affected samples embedded in LR white resin.

<p>A) and d) Survey sections stained with toluidine blue. B) and e) Sections stained with acridine orange for the detection of bacteria, as visualised by red fluorescence. In this case, red fluorescence is attributed to autofluorescence of host nuclei (e.g. mucocyte nuclei). C) and f) Nigrosin staining, targeting necrotic tissues. Block arrow indicates epithelium separated from underlying tissue, revealing a cleft (represented by the asterisk). Dashed arrow highlights growth from a centralised area. Scale bars = 10 µm.</p

Representative histological sections from healthy (a, b and c) and blister-affected (d, e and f) <i>Echinopora lamellosa</i> tissues embedded in LR white resin.

<p>Blister sections were taken at the blister-affected interface. A) and d) Survey sections stained with toluidine blue (E = epidermis, G = gastrodermis and Me = mesoglea). B) and e) Sections stained with acridine orange for the detection of bacteria, as visualised by red fluorescence. In this case, red fluorescence is attributed to autofluorescence of symbiotic algae nuclei and coral mucus (Mu). C) and f) Nigrosin staining, targeting necrotic tissues. Scale bars = 10 µm.</p

Additional file 1 of Identification and characterisation of Gamma-herpesviruses in zoo artiodactyla

Supplementary Material

Additional file 3 of Identification and characterisation of Gamma-herpesviruses in zoo artiodactyla

Supplementary Material