Listeriosis in an immature black buck antelope (Antilope cervicapra)

A 10-week-old, black buck antelope calf, from the Mesker Park Zoo in Evansville, Indiana was found dead without observed signs of illness. Necropsy disclosed disseminated ecchymoses on the pericardium, diaphragm, intestines, and renal capsules and more extensive hemorrhage in the muscles of the hindquarters. There were numerous, 1 mm, pale foci on the capsular and cut surfaces of the liver and spleen which, on microscopic examination, were necrotic foci containing variable numbers of neutrophils and mononuclear leukocytes with numerous, short, Gram-positive, cocco-bacilli at the periphery. Listeria monocytogenes was isolated from the liver. Septicemia is the most common form of listeriosis in non-domestic ruminants. Listeriosis should be suspected when unexpected deaths are accompanied by multifocal necrotizing hepatitis and splenitis, myocarditis, and disseminated hemorrhage.     

Spermatogonial stem cells in the testis of an endangered bovid: Indian black buck (Antilope cervicapra L.)

Numerous wild bovids are facing threat of extinction owing to the loss of habitat and various other reasons. Spermatogonial stem cells (SSCs) represent the only germline stem cells in adult body that are capable of self-renewal and that can undergo differentiation to produce haploid germ cells. SSCs can, therefore, serve as a useful resource for preservation of germplasm of threatened and endangered mammals. The Indian black buck (Antilope cervicapra L.) is a small Indian antelope that is listed as endangered by the Indian Wildlife Protection Act, 1972. Immunohistochemical analysis of testes tissues of black buck revealed the presence of spermatogonia that were specifically stained by lectin-Dolichos biflorus agglutinin (DBA). The expression of pluripotent cell-specific markers, NANOG and stage-specific embryonic antigen-1 (SSEA-1), was detected in spermatogonia. Interestingly, the expression of POU5F1 (OCT3/4) was absent from spermatogonia, however, it was detected in differentiating cells such as spermatocytes and round spermatids but not in elongated spermatids. The expression of NANOG protein was also present in spermatocytes but absent in round and elongated spermatids. Using the testis transplantation assay, stem cell potential of black buck spermatogonia was confirmed as indicated by the presence of colonized DBA-stained cells in the basal membrane of seminiferous tubules of xenotransplanted mice testis. The findings from this study suggest the presence of SSCs in the testis of an endangered bovid for the first time and open new possibility to explore the use of SSCs in conservation.     

Ectoparasites of the blackbuck antelope (Antilope cervicapra).

Fifty-two free-ranging blackbuck antelope (Antilope cervicapra) from Texas were examined for ectoparasites. Two species of sucking lice (Anoplura), one species of chewing louse (Mallophaga), one species of louse fly (Diptera), and three species of ticks (Acari) were found. This is the first report of the anoplurans Linognathus cervicaprae and L. pithodes from the Western Hemisphere. The southern deer ked (Lipoptena mazamae), the winter tick (Dermacentor albipictus), and the rabbit tick (Haemaphysalis leporispalustris) are reported from blackbuck for the first time. The lone star tick (Amblyomma americanum) and the mallophagan (Damalinia cornuta cornuta) were reported previously from blackbuck in Texas, the latter species under the name Tricholipeurus balanicus balanicus.     

Genetic diversity and phylogenetic analysis of blackbuck (Antilope cervicapra) in southern India

Blackbuck (Antilope cervicapra) is a threatened species endemic to the Indian subcontinent. Many populations of blackbuck are found in southern India. Populations of blackbuck are negatively affected in many places for various reasons, such as habitat destruction and poaching. Their range decreased sharply during the 20th century. There is very limited information available on the population dynamics of blackbuck in southern India. For the phylogenetic and genetic diversity analyses of blackbuck populations among different distribution ranges in southern India, we sequenced mt DNA of cytochrome b (Cyt b) for 120, cytochrome c oxidase subunit-1 (COI) for 137 and the control region (CR) for 137 fecal pellets from eleven different locations in southern India. We analyzed the genetic structure of three mitochondrial markers, the CR, Cyt b and the COI region, separately and in a combined dataset. The haplotype diversity and nucleotide diversity of CR were 0.969 and 0.047, respectively, and were higher than those of Cyt b and COI. A Bayesian phylogeny and an MJ network based on the CR and combined dataset (105 sequences) signified several distinct haplotype clusters within blackbuck, whereas no clusters were identified with the Cyt b and COI phylogenetic analyses. The analysis of molecular variance of the combined data set revealed 52.46% genetic variation within the population. Mismatch distribution analysis revealed that blackbuck populations underwent complex changes with analysis of the combined dataset in each population and analysis of each marker separately in the overall population. The results provide evidence that blackbuck in different geographic locations has a distinct population structure due to habitat fragmentation after the formation of the Western and Eastern Ghats.

     

Evaluation of matrices in the rumen simulation technique (RUSITEC) for the maintenance of ciliate protozoa

A number of inert matrices have been evaluated with a rumen simulation technique (RUSITEC) to provide a more defined culture medium for the cultivation of rumen protozoa in vitro . All of the inert matrices tested retained rumen protozoa longer than vessels run without a matrix (up to 7 d with matrix, less than 3 d with no matrix). A semi-inert digested hay matrix retained protozoa for up to 13 d, as did fresh hay.     

Unusually large sex chromosomes in the sitatunga (Tragelaphus spekei) and the blackbuck (Antilope cervicapra)

Sex chromosomes in mammals are generally of the XY type with the X chromosome constituting 5% by weight of the haploid chromosomal complement. Unusually large sex chromosomes have been described in a few species all of which belong to theRodentia, but two members of theArtiodactyla, the African sitatunga and the Indian blackbuck, have now been found to have this peculiarity. The sitatunga has an X chromosome that represents 13.08% and a Y that represents 7.29% of the haploid complement, and the X of the blackbuck represents 14.96% of its haploid complement. Portions of both extra large sex chromosomes in a pair are late replicating. Theories concerning the formation of these outsized chromosomes are discussed.     

The cryopreservation of some large ciliate entodiniomorphid protozoa taken from the rumen

M.H.P. FUNGARO, M.L.C. VIEIRA, A.A. PIZZIRANI-KLEINER AND J.L. DE AZEVEDO. 1996. Random amplified polymorphic DNA (RAPD) was used in order to analyse the relationships among 13 isolates of Metarhizium anisopliae var. anisopliae . Six of them were isolated from Deois flavopicta (Stal) (Hemiptera—Homoptera: Cercopidae) in different regions of Brazil. The other seven were isolated from soil in Paraná State in Southern Brazil. The isolates were grouped by cluster analysis using Dice similarity index. The results show that isolates of M. anisopliae var. anisopliae are extremely diverse (47% similarity) but those isolated from D. flavopicta present only a moderate degree of variation (82% similarity) when compared with the wide diversity (31% similarity) found in the group isolated from soil. These results suggest that M. anisopliae var. anisopliae has developed host specificity.     

The role of ciliate protozoa in the lysis of methanogenic archaea in rumen fluid

Predation by ciliate protozoa can account for 90% of the eubacterial protein turnover in the rumen. However, little is known about the factors affecting the lysis of archaea in rumen fluid. Bacterial lysis was followed from the release of acid-soluble ¹⁴C from ¹⁴C leucine-labelled bacteria. The rumen methanogen Methanobrevibacter MF1 was broken down more rapidly than other non-ruminal archaea in rumen fluid withdrawn from sheep harbouring either a mixed protozoal population or monofaunated with Polyplastron multivesiculatum or Entodinium spp. The removal of protozoa from the rumen fluid had little effect on the breakdown of Methanobrevibacter , while lysis of the non-methanogenic ruminal bacterium Selenomonas ruminantium decreased by over 70%. Substantial lysis of Methanobrevibacter occurred in cell-free rumen fluid and thzis effect could be abolished by autoclaving. In view of the high number of bacteriophages in rumen fluid and susceptibility of ruminal bacteria to phage-induced lysis it is tempting to suggest that phages have a role in the lysis of archaea in rumen fluid.     

Subcellular distribution of polysaccharide depolymerase and glycoside hydrolase enzymes in rumen ciliate protozoa

The distribution of polysaccharide depolymerase and glycoside (acid) hydrolase activity in nine genera of rumen entodiniomorphid and holotrich ciliate protozoa was examined by differential centrifugation. Sedimentable activity was detected in all of the protozoa examined and occurred principally in fractions that were prepared by centrifugation at 1000g for 10 min, 10,000g for 10 min, and 20,000g for 20 min (fractions F1, F2, and F3). Acid phosphatase was present in these subcellular fractions which contained membrane-bound vesicles 0.1–0.8 m in size. The enzyme location profile of the subcellular fractions differed within the genera examined. The distribution of the enzyme activity in the subcellular fractions indicated the presence of distinct populations of hydrolase-containing organelles and other functional vesicles in the rumen ciliates.     

The role of the rumen ciliate protozoa for methane suppression caused by coconut oil

Diets containing either coconut oil or rumen-protected fat (54 g kg⁻¹ dry matter each) were supplied to Rumen Simulation Technique fermenters filled with faunated and defaunated rumen fluid in a 2 × 2 factorial design. Defaunation immediately reduced methane formation by about 40% with each diet. With coconut oil, methane gradually declined in faunated and defaunated rumen fluid. Finally, the extent of methane suppression was similar, both with coconut oil and with defaunation. Independently of the status of protozoa, the population of methanogens in rumen fluid was significantly reduced by coconut oil. The results suggest that defaunation and coconut oil independently and additively suppress rumen methanogenesis.     

Influence of ciliate protozoa on biochemical changes and hydrolytic enzyme profile in the rumen ecosystem

AIMS: To assess the effect of presence or absence of rumen protozoa on fermentation characteristics and enzyme profile in growing lambs. METHODS AND RESULTS: Weaner lambs (G1, G2, G3, G4, G5 and G6 groups) were defaunated by oral administration of sodium laurel sulphate (at 8 g 100 kg(-1) body weight). The lambs of G4, G5 and G6 groups were refaunated. The roughage and concentrate ratio in the diet of G1 and G4, G2 and G5, and G3 and G6 were 50:50 (R1), 65:35 (R2) and 80:20 (R3), respectively. Daily dry matter intake was similar in defaunated and faunated lambs. However, digestibility of organic matter (OM), cellulose and gross energy were lower in defaunated lambs while crude protein (CP) digestibility was similar in both defaunated and faunated lambs. The rumen pH and NH3-N were lower (P < 0.01) while TVFA, total-N and TCA-ppt-N were higher (P < 0.01), in defaunated lambs. Ruminal activity of carboxymethyl cellulase was lower (P < 0.01) in defaunated lambs and amylase, xylanase, protease and urease were similar in faunated and defaunated lambs. Nutrient utilization, rumen metabolites and ciliate protozoal count were higher, whereas digestibility of fibre fractions was lower in high rather than low concentrate fed lambs. The rumen protozoa present before defaunation were B-type and the protozoa which re-established on refaunation were also B-type. CONCLUSIONS: Absence of ciliate protozoa decreased nutrient digestibility and increased ruminal TVFA and total-N with lower NH3-N concentration, indicating better energy and protein utilization in defaunated lambs. SIGNIFICANCE AND IMPACT OF THE STUDY: Defaunation improved energy and protein utilization in lambs.     

Interactions between rumen anaerobic fungi and ciliate protozoa in the degradation of rice straw cell walls

Suspensions of mixed rumen protozoa were added to incubations of the anaerobic fungus Neocallimastix patriciarum with rice straw cell walls. The protozoa did not influence the dry matter lost from the straw, or the solubilization of monosaccharides, but they had a marked effect on the fermentation products formed. Studies with ¹⁴C-labelled protozoa suggested that the presence of protozoa reduced the fungal carboxymethylcellulase activity to around half of that found in pure cultures of the fungus.     

The influence of headspace gas composition on the production of VFA by rumen ciliate protozoa

Aerobic bacterial growth was assessed in a simple rectangular vessel with good mixing achieved solely by air flow. Growth became oxygen limited at culture densities below 1·5 mg dry wt/ml, even at maximum air flow and the extent of oxygen-sufficient growth depended on the volume of the culture and the air flow rate. However, the system permitted high retention of biomass growing attached to kiesel-ghur beads, indicating conditions of low shear. The system may be suitable for cheap cultivation of slow-growing micro-organisms and for anaerobic or shear-sensitive cultures.     

Effect of ciliate protozoa on the activity of polysaccharide-degrading enzymes and fibre breakdown in the rumen ecosystem

The effect of ciliate protozoa on the activity of polysaccharide-degrading enzymes in microbial populations from the digesta solids and liquor fractions of rumen contents was examined after the refaunation of ciliate-free sheep with an A-type rumen protozoal population. Although the culturable rumen bacterial population was reduced after refaunation the number of fibrolytic micro-organisms detected was higher; the xylanolytic bacterial population and numbers of fungal zoospores were increased after refaunation. The proportion of propionic acid was lower in the refaunated animals, whereas the concentration of ammonia and the acidic metabolites acetate, butyrate and valerate were all increased. The range of enzyme activities present in the digesta subpopulations were the same in defaunated and refaunated animals. The activities of the polysaccharide-degrading enzymes, however, were increased in the microbial populations associated with the digesta solids after refaunation, and at 16 h after feeding the activities were 4–8 times (β-d-xylosidase 20 times) higher than the levels detected in the adherent population from defaunated sheep. The protozoa, either directly through their own enzymes or indirectly as a consequence of their effects on the population size and activity of the other fibrolytic micro-organisms present, have an important role in determining the level of activity of polysaccharide-degrading enzymes in the rumen ecosystem. Although the extent of ryegrass ( Lolium perenne ) hay digestion was similar after 24 h in the absence or presence of protozoa, the initial ruminal degradation was higher in refaunated sheep.     

Effect of ciliate protozoa on the activity of polysaccharide-degrading enzymes and fibre breakdown in the rumen ecosystem.

The effect of ciliate protozoa on the activity of polysaccharide-degrading enzymes in microbial populations from the digesta solids and liquor fractions of rumen contents was examined after the refaunation of ciliate-free sheep with an A-type rumen protozoal population. Although the culturable rumen bacterial population was reduced after refaunation the number of fibrolytic micro-organisms detected was higher; the xylanolytic bacterial population and numbers of fungal zoospores were increased after refaunation. The proportion of propionic acid was lower in the refaunated animals, whereas the concentration of ammonia and the acidic metabolites acetate, butyrate and valerate were all increased. The range of enzyme activities present in the digesta subpopulations were the same in defaunated and refaunated animals. The activities of the polysaccharide-degrading enzymes, however, were increased in the microbial populations associated with the digesta solids after refaunation, and at 16 h after feeding the activities were 4-8 times (beta-D-xylosidase 20 times) higher than the levels detected in the adherent population from defaunated sheep. The protozoa, either directly through their own enzymes or indirectly as a consequence of their effects on the population size and activity of the other fibrolytic micro-organisms present, have an important role in determining the level of activity of polysaccharide-degrading enzymes in the rumen ecosystem. Although the extent of ryegrass (Lolium perenne) hay digestion was similar after 24 h in the absence or presence of protozoa, the initial ruminal degradation was higher in refaunated sheep.