Rumen Ciliate Protozoa of the Blue Duiker (Cephalophus monticola), with Observations on Morphological Variation Lines Within the Species Entodinium dubardi

ABSTRACT. Protozoal concentrations were determined in rumen and cecal contents of 20 blue duikers ( Cephalophus monticola ). Ten animals of each sex were fed either a high concentrate or high roughage diet. Rumen protozoa were present in 19 of the 20 animals and concentrations ranged from 4.5 to 33.7 × 10⁶ per g of rumen contents. At the higher concentrations, protozoal cells equaled between 30–40% of the total rumen contents volume. No protozoa were found in cecal contents. Weight of rumen contents was higher in females than in males ( P < 0.01), and rumen protozoa concentrations were higher in males ( P < 0.05) and in those animals fed the high concentrate diet ( P < 0.05). All the protozoa were identified as belonging to a single species, Entodinium dubardi . However, an average of about 30% of the E. dubardi cells varied from the typical morphology of this species. These cells appeared to be on variation lines leading toward 7–10 other non-caudate species of Entodinium . The present data were used to evaluate and discuss the concept of variation lines within E. dubardi .     

Detection and Avoidance of Predators in White-Tailed Deer (Odocoileus virginianus) and Mule Deer (O. hemionus)

In this paper, we investigate the relationship between early detection of predators and predator avoidance in white-tailed deer ( Odocoileus virginianus ) and mule deer ( O. hemionus ), two closely related species that differ in their habitat preferences and in their anti-predator behavior. We used observations of coyotes ( Canis latrans ) hunting deer to test whether the distance at which white-tails and mule deer alerted to coyotes was related to their vulnerability to predation. Coyote encounters with both species were more likely to escalate when deer alerted at shorter distances. However, coyote encounters with mule deer progressed further than encounters with white-tails that alerted at the same distance, and this was not due to species differences in group size or habitat. We then conducted an experiment in which a person approached groups of deer to compare the detection abilities and the form of alert response for white-tails and mule deer, and for age groups within each species. Mule deer alerted to the approacher at longer distances than white-tails, even after controlling for variables that were potentially confounding. Adult females of both species alerted sooner than conspecific juveniles. Mule deer almost always looked directly at the approacher as their initial response, whereas white-tails were more likely to flee or to look in another direction with no indication that they pinpointed the approacher during the trial. Mule deer may have evolved the ability to detect predators earlier than white-tails as an adaptation to their more open habitats, or because they need more time to coordinate subsequent anti-predator defenses.     

Growth hormone and cortisol levels in the annual cycle of white-tailed deer (Odocoileus virginianus).

The annual cycles of growth hormone and cortisol levels in white-tailed deer were followed. No significant difference was found in the average cortisol levels in a large group of animals during the year. In contrast to cortisol, growth hormone (GH) investigated by heterologous bovine GH radioimmunoassay, seems to have a distinct annual rhythm. High levels of GH in plasma were found between casting and the first week of antler growth with the peak of 23.1 ng/ml (estimated in bovine GH equivalents) in the middle of April. From the middle of June until the middle of November a plateau averaging 3 ng/ml was found. The relationships between very rapid growth of a bone tissue and the influence of GH and sex hormones are discussed.     

The Potential for Transmission of BCG from Orally Vaccinated White-Tailed Deer (Odocoileus virginianus) to Cattle (Bos taurus) through a Contaminated Environment: Experimental Findings

White-tailed deer (Odocoileus virginianus) experimentally infected with a virulent strain of Mycobacterium bovis have been shown to transmit the bacterium to other deer and cattle (Bos taurus) by sharing of pen waste and feed. The risk of transmission of M. bovis bacille Calmette-Guerin (BCG) vaccine from orally vaccinated white-tailed deer to other deer and cattle, however, is not well understood. In order to evaluate this risk, we orally vaccinated 14 white-tailed deer with 1×10⁹ colony forming units BCG in lipid-formulated baits and housed them with nine non-vaccinated deer. Each day we exposed the same seven naïve cattle to pen space utilized by the deer to look for transmission between the two species. Before vaccination and every 60 days until the end of the study, we performed tuberculin skin testing on deer and cattle, as well as interferon-gamma testing in cattle, to detect cellular immune response to BCG exposure. At approximately 27 weeks all cattle and deer were euthanized and necropsied. None of the cattle converted on either caudal fold, comparative cervical tests, or interferon-gamma assay. None of the cattle were culture positive for BCG. Although there was immunological evidence that BCG transmission occurred from deer to deer, we were unable to detect immunological or microbiological evidence of transmission to cattle. This study suggests that the risk is likely to be low that BCG-vaccinated white-tailed deer would cause domestic cattle to react to the tuberculin skin test or interferon-gamma test through exposure to a BCG-contaminated environment.     

Effects of season and area on ectoparasites of white-tailed deer (Odocoileus virginianus) in Mississippi

Nine species of ectoparasites (4 Acari, 2 Mallophaga, 1 Anoplura, 1 Diptera, and 1 Siphonaptera) were recovered from 126 white-tailed deer collected in northern, central, and southern Mississippi. Intensity and prevalence of adults of Ixodes scapularis and larvae, nymphs, and adults of Amblyomma americanum varied significantly over collection periods, but not between host sexes. Lipoptena mazamae occurred on deer from only one study area. Although individual deer were heavily parasitized by Tricholipeurus parallelus and T. lipeuroides, their prevalence was limited. Hoplopsyllus sp., Solenopotes sp., Amblyomma maculatum, and Dermacentor albipictus had prevalences of less than 10% and were not tested for area, host sex, and seasonal effects. The potential pathogenicity of these ectoparasite species are related to white-tailed deer in Mississippi.     

Comparative morphology of Ostertagia mossi and Ostertagia dikmansi (trichostrongylidae) from Odocoileus virginianus and comments on other Ostertagia spp. from the Cervidae

The synlophes of Ostertagia mossi Dikmans, 1931 and O. dikmansi Becklund & Walker, 1968 were found to be identical supporting recognition of these as the major and minor morphotypes, respectively, of a putative species pair within the Ostertagiinae. The cervical synlophe included three narrowly spaced, continuous, parallel ridges laterally and three parallel but more widely spaced ridges in the dorsal and ventral fields (Type II and Type A patterns, respectively). The disposition of the synlophe in conjunction with a long oesophageo-intestinal valve, and attributes of the genital cone and spicules are characteristics shared among other Ostertagia spp. from cervids in the Holarctic region that allow recognition of a species group morphologically distinct from the Ostertagiinae of domestic ruminants. The morphological similarity of O. mossi/O. dikmansi, O. leptospicularis Assadov, 1953/O. kolchida Popova, 1937 and O. gruehneri Skrjabin, 1929/O. arctica Mitzkewitsch, 1929 is substantial, but these species can be differentiated by small but constant differences in the synlophe and genital complex of males; females cannot be easily distinguished. The morphological similarity of this cryptic complex of species and their relatively restricted distribution among cervids suggests a coevolutionary history for hosts and parasites in the Holarctic region.     

Prevalence and serovars of Salmonella in the feces of free-ranging white-tailed deer (Odocoileus virginianus) in Nebraska

To determine the prevalence and serovars of Salmonella in free-ranging deer, we cultured feces from white-tailed deer (Odocoileus virginianus) harvested by hunters during a regular firearm season in southeastern Nebraska (USA). We recovered Salmonella from 5 (1%; 95% confidence interval: 0.37-2.20%) of 500 samples and identified four different Salmonella enterica serovars [Litchfield (1), Dessau (1), Infantis (2), and Enteritidis (1)]. Although the prevalence of Salmonella in free-ranging deer appears to be low, the serovars recovered are known to be pathogenic to humans and animals.     

Effects of fluoride emissions from a modern primary aluminum smelter on a local population of white-tailed deer (Odocoileus virginianus)

The influence of fluoride emissions from a modern aluminum smelter on concentrations of skeletal fluoride and dental fluorosis in a resident population of white-tailed deer was studied. The smelter was located on Mount Holly Plantation in South Carolina, and concentrations of skeletal fluoride in the deer collected at Mount Holly increased approximately five-fold 3 yr after the operation began. Increases in skeletal fluoride of less than two-fold were observed in deer obtained from Medway Plantation which has its nearest boundary 1.6 km from the smelter site. No dental fluorosis was observed in deer collected at Medway Plantation, but mild dental fluorosis was observed in a significant number of deer collected at Mount Holly Plantation. The dental fluorosis that was observed was not associated with incisor wear or with fluoride-induced molar wear. Osteofluorosis of mandibles or metacarpals was not observed in any of the deer obtained from either plantation. The data obtained from this study indicated that the presence of a modern aluminum smelter caused a detectable increase in concentration of skeletal fluoride in the resident population of white-tailed deer, but that no adverse health effects were seen.     

Assessment of the sexual and antler potential of the male white-tailed deer (Odocoileus virginianus) by Gn-RH stimulation test

Twelve mature white-tailed bucks were injected with gonadotropin regulating hormone (Gn-RH, 100 micrograms/deer) during the rut (November) and during the spring (April). In the rut, superior bucks (with actual or potential large body weight, trophy antlers and a high social rank) responded to Gn-RH with a small increase of LH (below 20 micrograms/ml) and a profound rise in testosterone (T) (30-50 ng/ml). The inferior animals exhibited high increase of LH (30-40 ng/ml) but a low rise in T (below 10 ng/ml). FSH levels increased only slightly after Gn-RH and the concentrations were not related to reproductive performance. During the spring, increase in LH levels after Gn-RH administration greatly exceeded the rise of T, but no relationship was found between hormonal levels and the reproductive potential. FSH levels increased remarkably after Gn-RH administration. Gn-RH (administered during the rut) might be used for assessment of the potential for reproductive and antler performance.     

Distribution of Spiculopteragia pursglovei and S. odocoilei (Nematoda: Trichostrongyloidea) from white-tailed deer (Odocoileus virginianus) in the southeastern United States

The distribution of Spiculopteragia pursglovei (= Apteragia pursglovei) and S. odocoilei (= A. odocoilei) in 12 southeastern states was determined after examining the abomasal contents of 1,369 white-tailed deer over an 8-yr period. Spiculopteragia odocoilei was encountered with much greater frequency than S. pursglovei except in some areas along the Mississippi River drainage and the coasts of North Carolina and South Carolina. In instances where both parasites were found in a population, one usually expressed a dominance in both prevalence and intensity. These findings are in agreement with those of an earlier study conducted in the southeastern United States.     

Medicated corn feeders to disinfest cattle fever ticks,Boophilus (Boophilus) microplus (Acari: Ixodidae), from a suburban population of white-tailed deer,Odocoileus virginianus (Cervidae)

Following its eradication from the USA, the cattle fever tick, Rhipicephalus (Boophilus) microplus (Canestrini), a vector of bovine babesiosis, has made episodic incursions into, and sometimes beyond, an established barrier zone separating tick-free from endemic areas. In large part the incursions involve hosting and transport by wild ungulates, particularly deer and antelope. One approach to disinfest ticks from wild hosts is with food baits medicated to stop parasites. The approach has had mixed success due to factors that have been previously identified with supplemental feeding of wildlife especially competition for the bait, social dominance behavior, and the availability of alternative food sources. Given that not all of the target hosts will intake a therapeutic dose of the medication (ivermectin) at all seasons of the year, an open question is whether the approach is efficacious as a stand-alone treatment or even as part of an integrated program. As detailed in the present study an intensive effort was successful in eradicating a local outbreak of fever ticks.

     

Determination and evaluation of an optimal dosage of carfentanil and xylazine for the immobilization of white-tailed deer (Odocoileus virginianus)

Using an iteration method, optimal hand-injected immobilization dosages of carfentanil/xylazine (CAR/XYL) were determined for 13 adult white-tailed deer (Odocoileus virginianus). Deer were temporarily restrained in a squeeze chute and were repeatedly immobilized one to four times at 2-5-wk intervals from December 2002 to March 2003. A fixed ratio of 1 mg CAR:10 mg XYL intramuscularly was used, increasing or decreasing the dosage until the optimal dosage (defined by an induction time < 3 min and PaCO(2)< 60 mmHg) was reached for each animal. Inductions were video-recorded and reviewed by observers blinded to drugs and dosages, who rated qualitative aspects of each induction. There were significant (P < 0.05) dosage-dependent decreases in induction time, time to first effect, PaO(2), SaO(2), and arterial pH, and significant dosage-dependent increases in PaCO(2) and quality ratings. The median optimal dosage (mOD) was 0.03 (range, 0.015-0.06) mg/kg CAR+0.3 (range, 0.15-0.6) mg/kg XYL. Induction times using the mOD were rapid (median 3.0 min [range, 1.8-10.0]), but quality ratings were considered undesirable for nine of 13 deer. Increased rectal body temperatures of 40.6+/-0.5 C (mean +/- SD) were noted in all deer and hyperthermia (T > 41 C) was noted in three. There was a positive correlation between body temperature and induction time (r=0.44). Heart rates significantly decreased from 5 to 15 min postinduction and remained decreased at the 20-min reading; there was occasional bradycardia. There was a significant increase in pH from 10 to 20 min postinduction, but metabolic acidemia (pH<7.3) persisted throughout the immobilization periods for all deer. Possible hypoxemia (SaO(2) and SpO(2)<90 mmHg but PaO(2)>60 mmHg) was present after induction, while hypercapnea (PaCO(2) > 60 mmHg) did not occur. Reversal times with naltrexone and yohimbine were rapid (mean 3.7+/-1.5 min) and uneventful, with no evidence of renarcotization. Although the median optimal dosage produced rapid inductions, no respiratory depression, complete reversal after antagonist administration, and no renarcotization, negative attributes included elevated body temperatures, acidemia, and undesirable induction qualities.     

Observations on the Fine Structure of the Nuclear Apparatus of Blepharisma intermedium Bhandary (Ciliata: Spirotricha)

SYNOPSIS. An electron-microscope study of the macronucleus and the micronucleus of Blepharisma intermedium Bhandary has been made. Sections show that the macronucleus is bounded by a double membrane. Inside, there are two types of bodies: (a) small irregular bodies, from 0.05 to 0.2 μ in diameter, and (b) larger bodies, from 0.4 to 0.6 μ in diameter. The former are intrepreted as cut ends of long, branching filaments traversing the nuclear cavity in all directions. They correspond to the DNA filaments obtained by centrifugation and KCN action on the macronucleus. Each filament is made of fibrils aboue 150 Å thick. The large bodies correspond to the nucleoli; they also show a fibrillar structure. They offer the added interest of displaying dense particles, from 100 to 800 Å in size, whose nature and significance are obscure. The micro-nucleus has a double membrane, and the contents are divisible into an electron-dense network and a material of low density which fills the interstices of the network.