Systemic sarcocystosis in a wild turkey from Georgia

Acute sarcocystosis was diagnosed in an adult female wild turkey (Meleagris gallopavo) that was collected from Early County (Georgia, USA) in February of 1998. Marked inflammatory lesions were seen in the heart, lung, and liver and were associated with protozoal schizonts and merozoites. The organisms were identified as Sarcocystis sp. (Acomplexa: Sarcocystidae) based on structure and antigenicity. Protozoa divided by endopolygeny, merozoites lacked rhoptries, and the organisms did not react to anti-S. falcatula antibodies but reacted to anti-S. cruzi antibodies.     

Reticuloendotheliosis in a wild turkey (Meleagris gallopavo) from coastal Georgia.

An emaciated wild turkey (Meleagris gallopavo) exhibiting neurologic signs was found on Ossabaw Island, Chatham County, Georgia (USA) on 11 April 1989. The neurologic abnormalities observed included ataxia, drooping wings, head tremors, torticollis, and circling. At necropsy, discrete yellowish-white nodules, varying in size from 2 to 5 mm, were present in the spleen. White nodular lesions approximately 2 mm in diameter were observed beneath the mucosal surface of the distal esophagus. Histopathologic examination of the splenic nodules disclosed large numbers of primitive lymphoreticular cells with leptochromatic nuclei and abundant, slightly basophilic cytoplasms. The mitotic index in these cells was moderate to high. Similar neoplastic cells composed the masses observed in the esophagus. Multifocal, mild perivascular cuffing with mononuclear cells was found in the lumbar spinal cord, brain, and brain stem. Reticuloendotheliosis virus, subtype 3, was isolated from samples of the spleen and liver.     

Aflatoxin synthesis in corn fields in Guanajuato, Mexico

Aflatoxin contamination of corn is an important problem internationally, particularly in tropical and subtropical conditions that favor infection and synthesis by Aspergillus. Environmental conditions (drought) and agronomic practices i.e. N fertilization have been reported as favorable to aflatoxin synthesis in the field. This study was undertaken to investigate whether the contamination of corn commonly observed in stored conditions in this important corn producing region of Mexico known as "El Bajio" is related to infection by Aspergillus under field conditions. Results using three corn hybrids of recognized susceptibility to infection showed that corn ears artificially inoculated in the field with a toxigenic strain of Aspergillus parasiticus presented a low content of aflatoxin ranging from 13.6 to 24.7 microg Kg(-1). No significant differences were observed between the hybrids tested. Similarly, N fertilization practices, 260 Kg N ha(-1), applied at sowing did not have an effect on the extent of the contamination observed of 6.2 and 19.3 mg of aflatoxin kg(-1) in natural infected and inoculated samples with A. parasiticus NRRL 2999, respectively. Our data suggest that the cases of aflatoxin contamination of corn in this part of Mexico are not related to infection occurring during the crops growing period but most probably to poor storage conditions of corn.     

Multiple feather follicle cysts in a wild turkey

A hunter-killed wild turkey (Meleagris gallopavo silvestris) was submitted for examination because of numerous 2 to 30 mm diameter, yellowish, hard nodules in the skin. The nodules were confined to the skin and did not involve subcutaneous tissues. Nodules consisted of dilated feather follicles packed with a caseous tan to pale yellow material. Histologically, affected feather follicles were markedly dilated and filled with laminated keratin debris. The lesions were determined to be multiple feather follicle cysts of unknown etiology.     

The wild turkey as a host for Heterakis gallinarum and Histomonas meleagridis.

Freshly embryonated eggs of Heterakis gallinarum gathered from naturally infected domestic turkeys and chickens developed the first 4 weeks essentially as well in young wild turkeys as in domestic poults, but then became progressively retarded and failed in most birds to result in females with fertile eggs. There was no significant difference in the prevalence or progress of infections with Histomonas meleagridis in the two kinds of turkeys, both of which differed from chickens only in that the latter had neither liver involvement nor mortality. In a second test, heterakids hatched from eggs stored 5-6 months at 4 C (comparable to overwintering) sustained very heavy losses in all birds, with greatly accelerated liberations of H. meleagridis, Few worms reached maturity and still fewer produced fertile eggs. In turkeys, and especially in wild turkeys, replacement of infective stages was so poor, that these birds were of no importance in contaminating the soil.     

Metroliasthes lucida in the eastern wild turkey from Rhode Island

The cestode, Metroliasthes lucida, is reported for the first time from the eastern wild turkey (Meleagris gallopavo) in Rhode Island, United States; this is the first published record from New England. One of eight birds examined was infected with 10 cestodes.     

Factors influencing rate of decline in a Merriam's wild turkey population

We investigated population growth rate (λ) for a Merriam's wild turkey (Meleagris gallopavo merriami) population in the northern Black Hills, South Dakota, USA. We constructed and evaluated a females-only matrix population model. Our estimate of asymptotic λ, derived from estimates of vital rates obtained from 2016–2018 was 0.74 (95% CI = 0.60, 0.88), which indicates that the vital rates were inadequate to sustain the population. Elasticity values were highest for changes in adult survival probability followed by, in order, changes in juvenile survival, yearling survival, and adult reproduction. We could only achieve stable or growing populations (i.e., λ ≥ 1) by increasing the probability of adult and yearling survival (holding all other vital rates constant). Estimated adult survival rate in the work reported here was lower than values reported for other populations in the Black Hills; therefore, managing for increased female survival (≥0.68) may be the most practical strategy for promoting wild turkey population growth in this system. We recommend no female harvest during any open turkey season.     

Risk factors associated with capture-related death in eastern wild turkey hens

Capture-related mortality has been a notable risk in the handling of eastern wild turkey (Meleagris gallopavo silvestris). Our objective was to evaluate how environmental factors influence risk and identify physiological correlates that could be used to identify susceptible birds. During winter (January-March) 1995-97, 130 eastern wild turkey hens were captured in southeastern Oklahoma and radiocollared. Of those, 20 hens died < or =14 days of capture. Serum creatine kinase activity (CK; P < 0.01), body temperature (P < 0.01), processing time (P = 0.02), and ambient temperature (P < 0.01) showed a positive relationship with mortality that occurred within 14 days of capture. Plasma corticosterone concentration (P = 0.08) and relative humidity (P < 0.01) showed a negative relationship with mortalities that occurred within 14 days post-capture. Stepwise logistic regression selected CK activity, relative humidity, and ambient temperature as the best predictors of mortality within 14 days post-capture. Our data suggest that susceptible individuals may be identified from CK activity and that capture-related mortality may be minimized by establishing guidelines of when to curtail capture operations based on various weather conditions.     

Prevalence of parasitism by Amblyomma americanum on wild turkey poults as influenced by prescribed burning.

Captive-raised eastern wild turkey (Meleagris gallopavo silvestris) poults were allowed to forage on either recently burned plots or on plots that had not been burned during the previous 3 years. Following a two hour exposure on the study plots, external parasites were recovered from all poults. The louse (Menacanthus stramineus) and the lone star tick (Amblyomma americanum) were the only parasites recovered. Fifty-nine poults exposed to the burned plots had a significantly (P less than 0.001) lower prevalence of A. americanum infestation than did 57 poults exposed to the unbured plots. Thirty-five percent of the poults exposed to the unburned plots were infested by A. americanum. A single A. americanum was recovered from one poult exposed to burned plots.     

Aflatoxin in corn: ammonia inactivation and bioassay with rainbow trout.

Four samples of corn were compared with respect to their hepatocarcinogenicity in rainbow trout. One corn sample was found by chemical analysis to contain no detectable aflatoxin. A second sample was contaminated with aflatoxins at a level of 180 microgram/kg. Each of the above-mentioned samples was divided, and one-half of each was ammoniated. These four samples were added to a semipurified basal diet and fed to a sensitive strain of rainbow trout. It was found that ammoniation inactivated the aflatoxins and reduced the carcinogenicity of the contaminated corn to a level that was not significantly different from that with the basal control diet. It was also found that the ammoniation process did not reduce the nutritive value of the corn.     

Aflatoxin in corn: ammonia inactivation and bioassay with rainbow trout.

Four samples of corn were compared with respect to their hepatocarcinogenicity in rainbow trout. One corn sample was found by chemical analysis to contain no detectable aflatoxin. A second sample was contaminated with aflatoxins at a level of 180 microgram/kg. Each of the above-mentioned samples was divided, and one-half of each was ammoniated. These four samples were added to a semipurified basal diet and fed to a sensitive strain of rainbow trout. It was found that ammoniation inactivated the aflatoxins and reduced the carcinogenicity of the contaminated corn to a level that was not significantly different from that with the basal control diet. It was also found that the ammoniation process did not reduce the nutritive value of the corn.     

Myocardial calcium levels in furazolidone-induced cardiomyopathy in turkey poults

Myocardial calcium levels were measured in control turkey poults and in poults with furazolidone (FZ)-induced cardiomyopathy. FZ at a dose of 700 ppm added to the feed of poults from 2 to 5 weeks post-hatching produced the typical round-heart syndrome but had little effect on the calcium levels in the myocardium. Data suggest that the mechanism of FZ cardiotoxicity is not associated with calcium overload.     

Pilot study on the efficacy of paromomycin as a histomonostatic feed additive in turkey poults experimentally infected with Histomonas meleagridis

Paromomycin is an aminoglycoside antibiotic with activity against protozoa. Currently, paromomycin is registered for food producing animal species. In a pilot study we evaluated the efficacy of different doses of paromomycin in the feed against Histomonas meleagridis in experimentally challenged turkey poults. Groups consisting of 30 birds each were given feed with 100, 200 and 400 ppm paromomycin, respectively, starting on day 1 through to day 42. One group of 30 birds was left untreated. On day 21 all birds were infected intracloacally with H. meleagridis. Additionally, 10 birds were kept as a non-infected and non-treated control group. Before the challenge there was no significant difference between untreated and treated groups with regards to feed consumption and feed conversion rate. After the challenge, mortality was 80% in the infected non-treated birds. In the treated groups the mortality rate was 73.3%, 43.3% and 20%, respectively. No histomonal DNA was found in caeca and livers of the surviving birds. In addition, higher doses of paromomycin (200 and 400 ppm) led to reduced counts of Clostridium perfringens in the droppings. In conclusion, a prophylactic application of paromomycin as a feed additive was effective against the challenge with H. meleagridis under experimental conditions.     

Nest site fidelity and dispersal of Rio Grande wild turkey hens in Texas

Rio Grande wild turkey (Meleagris gallopavo intermedia) nests suffer high predation rates exceeding 65%, which may limit recruitment. We evaluated post-nesting movements of reproductively active female Rio Grande wild turkeys. We monitored 194 nesting attempts between 2005 and 2010 and documented 17% and 32% overall apparent nest success for the Edwards Plateau and Central Rio Grande Plains study regions, respectively. Rio Grande wild turkey hens move approximately 1.2 km (SD = 0.7) between nesting attempts within a nesting season and approximately 1.4 km (SD = 1.6) between initial nesting attempts among years. Rio Grande wild turkey hens selected open areas with moderate woody cover for nesting ( = 37.7%; range = 3.0–88.2%). Patchiness of vegetation in the nesting landscape also was borne out by typically low edge-to-area ratios ( = 0.20; range = 0.040–0.732). We found no clear pattern in movement distance and either landscape composition or edge-to-area ratio for within or between breeding season nest site selection for either the Edwards Plateau or Central Rio Grande Plains study region. Based on our results, movement distances post-nest failure do not seem to influence habitat selection. © 2012 The Wildlife Society.