Pregnant White-tailed Deer Research Articles

Testing secondary sex ratio bias hypotheses in white-tailed deer in Mississippi, USA.

Natural selection favors individuals with the highest inclusive fitness (i.e., total number of descendants). In cases where one sex is more productive, one or both parents may maximize their inclusive fitness by investing in the offspring of the more prolific sex. Such preferential production can lead to skewed sex ratios at various life history stages, including at birth, resulting in secondary sex ratio bias. Several competing hypotheses have been proposed to explain observed variation in secondary sex ratios including Fisher's frequency dependence and two hypotheses related to maternal condition: Trivers-Willard and the local resource hypotheses. Although it has been shown that maternal condition can influence the number of offspring produced in white-tailed deer, there is no consensus as to which of the hypotheses drives sex ratio bias in wild populations. Using a spatiotemporally extensive dataset of pregnant white-tailed deer from Mississippi, USA, we examined fetal sex ratio in relation to the Fisherian frequency-dependence hypothesis and hypotheses related to maternal condition. While there was a male-sex ratio bias in pregnant females that reduced in intensity with the number of offspring, there was no support for condition-related hypotheses. Instead, secondary sex ratios for white-tailed deer in Mississippi were nearly consistent with Fisherian frequency dependence. Our findings add to the body of literature on secondary sex biases in white-tailed deer and help inform sex bias ratios for a southern population of a cervid of management importance in the US.

Infection and transmission of ancestral SARS-CoV-2 and its alpha variant in pregnant white-tailed deer

ABSTRACT SARS-CoV-2 was first reported circulating in human populations in December 2019 and has since become a global pandemic. Recent history involving SARS-like coronavirus outbreaks have demonstrated the significant role of intermediate hosts in viral maintenance and transmission. Evidence of SARS-CoV-2 natural infection and experimental infections of a wide variety of animal species has been demonstrated, and in silico and in vitro studies have indicated that deer are susceptible to SARS-CoV-2 infection. White-tailed deer (WTD) are amongst the most abundant and geographically widespread wild ruminant species in the US. Recently, WTD fawns were shown to be susceptible to SARS-CoV-2. In the present study, we investigated the susceptibility and transmission of SARS-CoV-2 in adult WTD. In addition, we examined the competition of two SARS-CoV-2 isolates, representatives of the ancestral lineage A and the alpha variant of concern (VOC) B.1.1.7 through co-infection of WTD. Next-generation sequencing was used to determine the presence and transmission of each strain in the co-infected and contact sentinel animals. Our results demonstrate that adult WTD are highly susceptible to SARS-CoV-2 infection and can transmit the virus through direct contact as well as vertically from doe to fetus. Additionally, we determined that the alpha VOC B.1.1.7 isolate of SARS-CoV-2 outcompetes the ancestral lineage A isolate in WTD, as demonstrated by the genome of the virus shed from nasal and oral cavities from principal infected and contact animals, and from the genome of virus present in tissues of principal infected deer, fetuses and contact animals.

IMPACT OF BVDV INFECTION OF WHITE-TAILED DEER DURING SECOND AND THIRD TRIMESTERS OF PREGNANCY

While it has been demonstrated that persistent bovine viral diarrhea virus (BVDV) infections can be established in white-tailed deer (Odocoileus virginianus) following in utero exposure in the first trimester of gestation, there is little to no information regarding the outcome of infection in later stages of pregnancy in deer. Our goal was to observe the impact of infection of white-tailed deer in the second and third trimesters of pregnancy. Five white-tailed deer in the second trimester of pregnancy and four in the third trimester were infected with a BVDV type 2 virus previously isolated from a BVDV-infected deer harvested from the wild. Infection of deer in the second trimester of pregnancy resulted in loss of the pregnancy in three of five deer. Fawns born to the two remaining deer appeared normal and were born BVDV antigen-negative with neutralizing serum antibodies against BVDV. Infection of does in the third trimester of pregnancy did not result in fetal death or persistent infection and all does gave birth to live, healthy fawns that were BVDV antigen-negative and born with antibodies against BVDV. These results, combined with those previously reported regarding BVDV infection in the first trimester of pregnancy, suggest that the impact of BVDV infection of pregnant white-tailed deer is very similar to that observed in pregnant cattle.

Transmission of bovine viral diarrhea virus among white-tailed deer (Odocoileus virginianus)

Cattle persistently infected (PI) with bovine viral diarrhea virus (BVDV), a pestivirus in the family Flaviviridae, are an important source of viral transmission to susceptible hosts. Persistent BVDV infections have been identified in white-tailed deer (Odocoileus virginianus), the most abundant free-ranging ruminant in North America. As PI deer shed BVDV similarly to PI cattle, maintenance of BVDV within white-tailed deer populations may be possible. To date, intraspecific transmission of BVDV in white-tailed deer has not been evaluated, which prompted this study. Six pregnant white-tailed deer were captured in the first trimester of pregnancy and cohabitated with a PI white-tailed deer. Cohabitation with the PI deer resulted in BVDV infection in all does, as indicated by seroconversion. All does gave birth to live fawns and no reproductive losses were observed. At birth, evidence of BVDV infection was identified in two singlet fawns, of which one was determined to be PI by repeated serum reverse transcription nested PCR, whole blood virus isolation and immunohistochemistry. This study demonstrates for the first time that BVDV transmission may occur among white-tailed deer. The birth of a PI fawn through contact to a PI white-tailed deer indicates that under appropriate circumstances, BVDV may be maintained in white-tailed deer by congenital infection.

Reproductive tract disease associated with inoculation of pregnant white-tailed deer with bovine viral diarrhea virus

To inoculate white-tailed deer (Odocoileus virginianus) during the sixth or seventh week of gestation with bovine viral diarrhea virus (BVDV) and observe for signs of reproductive tract disease during a 182-day period. 10 pregnant white-tailed deer (8 seronegative and 2 seropositive [control deer] for BVDV). Deer were inoculated with 1 of 2 deer-derived BVDV strains (RO3-20663 or RO3-24272). Serum anti-BVDV antibody titers were determined prior to and 21 or 35 days after inoculation. Virus isolation (VI) procedures were performed on tissues from fetuses and does that died and on blood samples collected from live fawns. Ear notch specimens obtained from live fawns were assessed by use of BVDV antigen-capture ELISA (ACE). Both RO3-20663-inoculated seropositive deer gave birth to apparently normal fawns. Among the RO3-24272-inoculated seronegative deer, 1 died, and 1 aborted and 1 resorbed their fetuses; among the RO3-20663-inoculated seronegative deer, 3 died, 1 aborted its fetus, and 1 gave birth to 2 fawns that were likely persistently infected. On the basis of VI and ACE results, those 2 fawns were positive for BVDV; both had no detectable neutralizing anti-BVDV antibodies in serum. Reproductive tract disease that developed in pregnant white-tailed deer following BVDV inoculation was similar to that which develops in BVDV-exposed cattle. Methods developed for BVDV detection in cattle (VI, immunohistochemical evaluations, and ACE) can be applied in assessments of white-tailed deer. Fawns from does that had serum anti-BVDV antibodies prior to inoculation were protected against BVDV infection in utero.

Reproductive tract disease associated with inoculation of pregnant white-tailed deer with bovine viral diarrhea virus

Reproductive tract disease associated with inoculation of pregnant white-tailed deer with bovine viral diarrhea virus

Transmission of Bovine Viral Diarrhea Virus from Persistently Infected Cattle to Pregnant White-tailed Deer

Substantial impact of bovine viral diarrhea virus (BVDV) on the cattle industries has prompted introduction of organized control programs in many states. These programs primarily focus on identification and removal of persistently infected (PI) cattle, the main source of BVDV transmission. In addition to cattle, BVDV may infect a large number of species within the order Artiodactyla as demonstrated by seropositivity. The white-tailed deer is the most abundant wild ruminant species in North America and BVDV infection has been documented in this species. Recently, experimental inoculation of pregnant white-tailed deer resulted in the birth of a persistently infected fawn. Considering the role of PI cattle in the maintenance of BVDV within cattle populations, PI white-tailed deer that harbor and shed the virus continuously may hamper successful execution of control efforts. The objective of this study was the investigation of interspecific BVDV transmission by cohabitation of PI cattle with pregnant white-tailed deer.

Cohabitation of pregnant white-tailed deer and cattle persistently infected with Bovine viral diarrhea virus results in persistently infected fawns

Economic losses due to infection with Bovine viral diarrhea virus (BVDV) have prompted introduction of organized control programs. These programs primarily focus on the removal of persistently infected (PI) animals, the main source of BVDV transmission. Recently, persistent BVDV infection was demonstrated experimentally in white-tailed deer, the most abundant wild ruminant in North America. Contact of cattle and white-tailed deer may result in interspecific BVDV transmission and birth of persistently infected offspring that could be a threat to control programs. The objective of this study was to assess the potential for interspecific BVDV transmission from persistently infected cattle cohabitated with pregnant white-tailed deer. Seven female and one male white-tailed deer were captured and bred in captivity. At approximately 50 days of gestation, two cattle persistently infected with BVDV 1 were cohabitated with the deer. In a pen of approximately 0.8 ha, both species shared food and water sources for a period of 60 days. Transmission of BVDV as indicated by seroconversion was demonstrated in all exposed adult deer. Of the seven pregnancies, four resulted in offspring that were infected with BVDV. Persistent infection was demonstrated in three singlet fawns by immunohistochemistry and ELISA on skin samples, PCR, and virus isolation procedures. Furthermore, two stillborn fetuses were apparently persistently infected. This is the first report of BVDV transmission from cattle to white-tailed deer using a model of natural challenge. Under appropriate circumstances, BVDV may efficiently cross the species barrier to cause transplacental infection and persistently infected offspring in a wildlife species.

Experimental persistent infection with bovine viral diarrhea virus in white-tailed deer

Bovine viral diarrhea virus (BVDV) infections cause substantial economic losses to the cattle industries. Persistently infected (PI) cattle are the most important reservoir for BVDV. White-tailed deer ( Odocoileus virginianus) are the most abundant species of wild ruminants in the United States and contact between cattle and deer is common. If the outcome of fetal infection of white-tailed deer is similar to cattle, PI white-tailed deer may pose a threat to BVDV control programs. The objective of this study was to determine if experimental infection of pregnant white-tailed deer with BVDV would result in the birth of PI offspring. Nine female and one male white-tailed deer were captured and housed at a captive deer isolation facility. After natural mating had occurred, all does were inoculated intranasally at approximately 50 days of pregnancy with 10 6 CCID 50 each of a BVDV 1 (BJ) and BVDV 2 (PA131) strain. Although no clinical signs of BVDV infection were observed or abortions detected, only one pregnancy advanced to term. On day 167 post-inoculation, one doe delivered a live fawn and a mummified fetus. The fawn was translocated to an isolation facility to be hand-raised. The fawn was determined to be PI with BVDV 2 by serial virus isolation from serum and white blood cells, immunohistochemistry on skin biopsy, and RT-PCR. This is the first report of persistent infection of white-tailed deer with BVDV. Further research is needed to assess the impact of PI white-tailed deer on BVDV control programs in cattle.

Fat Levels in Female White-Tailed Deer during the Breeding Season and Pregnancy

Levels of stored body fat, based upon the kidney fat index, were measured for 238 pregnant white-tailed deer through the gestation period and 866 nonpregnant female deer through the breeding season. The deer were collected on the Savannah River Plant (SRP) near Aiken, South Carolina. The percentage of stored body fat of pregnant deer decreased significantly over the length of pregnancy. The rate of fat loss was significantly related to the number of in utero fetuses, conception date, and individual genic heterozygosity but not age, weight, or habitat (either swamp or upland). Greatest fat loss in pregnant deer was for females with two fetuses or females that conceived early in the breeding season. Among nonpregnant females, fat levels increased significantly from September through December. Nonlactating females gained fat during this period at a significantly greater rate than lactating ones. Fat levels of nonpregnant deer differed among age classes but rate of fat increase during the breeding season was not associated with age. Fat levels of nonpregnant deer from the swamp habitat of the SRP were related significantly to individual heterozygosity, with higher levels of stored body fat in heterozygous female deer throughout the breeding season. These results indicate an association between individual heterozygosity and levels of stored energy of white-tailed deer which, in turn, may be related to reproductive success.

Effects on fawn survival of multiple immobilizations of captive pregnant white-tailed deer.

Fawn viability was tested in captive, pregnant white-tailed deer (Odocoileus virginianus) immobilized with xylazine hydrochloride and ketamine hydrochloride and reversed by yohimbine hydrochloride or tolazoline hydrochloride. Nine pregnant does were immobilized 10 times each from December 1984 to May 1985. Their mean parturition date was 8 June. The number of fawns produced per pregnant doe was 1.88. Mean weight of newborn fawns was 4.18 kg. Seventy-five percent of the does produced twins or triplets. Three (20%) fawns died postnatally within 48 hr, but the remaining 12 survived for the full 72 hr they were allowed to remain with their dams. These observations compare favorably with those of non-immobilized captive deer on similar diets.

Uterine Composition and Growth in Pregnant White-Tailed Deer

Uterine Composition and Growth in Pregnant White-Tailed Deer

Energy and Protein Influences on Blood Urea Nitrogen of White-Tailed Deer Fawns

Nineteen female white-tailed deer fawns (Odocoileus virginianus) were used in a 2 X 2 factorial experiment to determine the effect of 2 levels of energy and 2 levels of protein on food consumption, weight gains, and blood urea nitrogen over a 20-week period beginning when the animals were 3.5 months of age. The 2 levels of ration-digestible energy averaged 2,498 and 3,064 kcal/kg. The 2 levels of protein averaged 9.6 and 18.2 percent. Food consumption tended to be greater in animals on low energy diets but decreased in all treatment groups from November through February. Weight gains were significantly greater (P < 0.05) in animals on high protein diets, but no significant difference was found due to energy. Weight gains decreased significantly (P < 0.01) from the 8th through the 20th week of the experiment. Blood urea nitrogen (BUN) was significantly greater (P < 0.01) in fawns receiving high protein diets than in those receiving low protein. Conversely, fawns on high energy intakes had significantly lower (P < 0.01) BUN than those on low energy intakes. J. WILDL. MANAGE. 39(4):692-698 For several years wildlife biologists have sought indices which would correlate well with the recent nutritional status of deer (Odocoileus spp.) and thus would be useful for evaluating trends in habitat conditions. Bone marrow fat, antler development, rumen content analysis, abomasal parasite counts, and many different hematological characteristics have been examined by various authors. None has proven entirely satisfactory, and it is anticipated that as deer management becomes more intensive the need for good indices of deer and habitat conditions will increase. Recent work on BUN in both domestic and wild species has indicated that this easily-measured characteristic might be of use as an index of recent nutritional status. Torell et al. (1974) and Blowey et al. (1973) have shown that BUN levels can be used as indicators of protein intake in domestic sheep and cattle, respectively. Seal et al. (1972b) suggested that BUN levels also might be useful as an index of recent nutritional status of pregnant white-tailed deer and presented limited data to substantiate this. Further, work by Seal et al. (1972a) on white-tailed deer and Franzmann (1972) on bighorn sheep (Ovis canadensis) has shown that BUN levels are not readily affected by the excitement of restraint or immobilization with certain drugs. The present study was conducted to investigate further the possible use of BUN as an indicator of recent nutritional status of deer. More specifically, the study was to determine the effect of known levels of energy and protein intake on BUN concentration 692 J. Wildl. Manage. 39(4):1975 This content downloaded from 157.55.39.179 on Tue, 12 Apr 2016 10:12:35 UTC All use subject to http://about.jstor.org/terms BLOOD UREA NITROGEN OF DEER FAWNS ? Kirkpatrick et al. 693 Table 1. Ingredient composition of pelleted experimental

Bluetongue Virus: (1) In Pregnant White-tailed Deer (2) A Plaque Reduction Neutralization Test

Six white-tailed deer (Odocoileus virginianus) were infected with bluetongue virus (BTs, vaccinal strain) approximately one-third of the way through their gestation period. One deer died of bluetongue 21 days after inoculation. Of the five surviving the infection, one had two mummified fetuses, and the others no fetuses upon euthanasia two weeks after term. Fetuses were present in two control deer and in the one which died of bluetongue. A plaque reduction neutralization test for bluetongue virus was developed and described for the first time and its sensitivity illustrated by high post inoculation titers which ranged from 1:3200 to greater than 1:16000.

Digestibility of Cedar and Jack Pine Browse for the White-Tailed Deer

Fourteen pregnant white-tailed deer (Odocoileus virginianus), 2-5 years old, were used to study the digestibility of browse from northern white cedar (Thuja occidentalis) and from large-toothed aspen (Populus grandidentata). Consumption of cedar exceeded consumption of aspen three to seven times and weight loss was appreciably more in the latter group. The apparent digestibility of the dry matter, crude fiber, nitrogen-free extract, and gross energy of cedar generally exceeded the corresponding values for aspen. Cellular hematology differences between treatments were not significant, but total serum protein concentrations declined with time in both groups. The rumen liquor of aspen-fed deer had a higher concentration of ammonia nitrogen, expressed as a percent of total nitrogen, and a lower concentration of butyric, propionic, and acetic acids. White-tailed deer seek the security of yards during the depth of Michigan's winter when the temperatures are low and snow is deep. These yards are frequently low areas where northern white cedar offers protec- tion and food to deer tall enough to reach it. Some yearlings and numerous fawns are unable to do so, for many years of over-