Serologic evidence of infectious bursal disease virus infection in Iowa turkeys

Two infectious bursal disease viruses (IBDVs)--a cell-culture-adapted chicken strain designated Edgar strain and a recent isolate from turkeys in Missouri--were used to assay sera from 10 Iowa turkey flocks collected between 1 and 16 weeks of age. The two viruses were serologically distinct in cross-neutralization tests. For all flocks, a similar serologic pattern was found consisting of (1) low maternal antibody titers to turkey IBDV and occasionally to Edgar strain IBDV between 1 and 3 weeks of age, (2) a period of very low or no detectable titers between 3 and 7 weeks of age, and (3) sharply rising high titers to turkey IBDV with low titers to Edgar IBDV beginning at 5 to 8 weeks of age. These findings indicate that infection with IBDV of the serotype represented in this study by the turkey isolate is common in Iowa turkey flocks, whereas infection with IBDV represented by Edgar strain is uncommon. Infection occurred between 3 and 7 weeks of age during the late brooding period or after birds had been moved to an intermediate growing facility. All flocks developed complicated respiratory disease with excessive mortality caused by Escherichia coli septicemia, typically between 3 and 6 weeks of age. Although there was a temporal relationship between IBDV infection and respiratory disease, the possible role of IBDV in the process is unknown.     

Inclusion-body hepatitis in day-old turkeys

Inclusion-body hepatitis was diagnosed in 1-day-old turkeys experiencing above-average mortality. At necropsy, turkeys appeared anemic and had pale yellow livers. Histopathologic examination of affected livers revealed diffuse hepatic degeneration and multifocal necrosis, with approximately 70% of the hepatocytes containing large, basophilic, intranuclear inclusion bodies. An adenovirus was isolated from affected livers and identified as a group I avian adenovirus by indirect immunofluorescence.     

Effect of genetic selection for milk yield and increased milking frequency on plasma growth hormone and prolactin concentration in Holstein cows

Fifty Holstein cattle, either second to fourth generation daughters of cows randomly bred to non-commercial sires originating in the Virginia Tech dairy herd (estimated mean PDM84 = -455 kg, control animals), or daughters of cows bred to commercially available sires (mean PDM84 = +368 kg, selection animals), were randomly assigned to be milked twice or thrice daily starting at parturition. Serial blood samples were collected via jugular cannulae at 30, 90 and 200 d post-partum (DPP) during both the first and second lactations. Blood samples were collected for 3 h prior to and 4 h following thyrotropin releasing hormone (TRH) administration, and were analyzed for growth hormone (GH) and prolactin (PRL) concentrations. Dry matter intake, body weight and milk yield and fat content were used to calculate net energy balance (NEB) of animals at each DPP sampling period. Mean plasma GH concentrations were greater (P less than .01) in selection vs control animals both before and after TRH administration, and decreased (P less than .01) with advancing lactation (30 greater than 90 greater than 200 DPP). However, NEB was not influenced by genetic merit, implying that observed differences in GH concentrations were not due to that trait. Plasma PRL concentrations were not affected by genetic merit or DPP, but were greater (P less than .01) in the second vs first lactation. Neither PRL or GH concentrations were affected by frequency of milking. The results support the contention that increased plasma GH concentrations are associated with selection for increased milk yield.     

Intestinal cryptosporidiosis and reovirus isolation from bobwhite quail (Colinus virginianus) with enteritis

An acute enteric disease of young pen-raised bobwhite quails was studied. Affected quails had white, watery diarrhea accompanied by dehydration and subsequent death. Mortality from hatch to 17 days of age ranged from 30 to 45% in the three flocks examined. Small intestines were thin-walled and distended with fluid and gas. Microscopic lesions in the intestinal tract consisted of villus atrophy, villus fusion, and sloughing of cells at the tip of the villi in duodenum, jejunum, and ileum. Cryptosporidium sp. and reovirus were identified in affected quails.     

Acute airsacculitis in turkeys inoculated with Pasteurella multocida

Thirty female turkeys, inoculated into the caudal thoracic air sacs with Pasteurella multocida were examined from 0 to 6 hours post-inoculation (PI). The air sac reacted rapidly and intensely with exudation of heterophils. Circulating leukocyte and thrombocyte numbers remained normal except for an absolute lymphopenia by 6 hours PI. P. multocida was initially isolated from blood at 3 hours PI. Total cell counts increased markedly in air sac lavage fluids by 1.5 hours PI and continued to increase until 6 hours PI. Heterophils predominated in lavage fluids (greater than 94%), with macrophages comprising the remaining cells. Microscopically occasional heterophils were present within air sac blood vessels and perivascularly by 0.5 hour PI. They became more numerous by 1.5 and 3 hours PI when transepithelial migration into the air sac lumen was seen. By 6 hours PI, there was diffuse, severe swelling of air sac epithelium and mesothelium, and bacteria were located in air sac interstitium. Ultrastructurally, endothelial and air sac epithelial cells were swollen and vacuolated Interdigitating processes of air sac epithelial cells were separated. These results indicate that air sacs can be the portal of entry for P. multocida into the systemic circulation, probably via damaged air sac epithelium.     

Thrombocytopenia in Horses: 35 Cases (1989–1994)

The records of 3,952 equine patients presenting to the Veterinary Teaching Hospital at North Carolina State University College of Veterinary Medicine were evaluated to determine risk factors associated with thrombocytopenia. Of 2,346 horses from which a CBC was obtained, 35 (1.49%) were thrombocytopenic (platelet count < 75,000/μL). A reference population of 189 horses with normal platelet counts (75,000 to 300,000/μL) was also studied. Standardbred horses were at increased risk for thrombocytopenia. but age and gender were not identified as significant risk factors. Horses with infectious or inflammatory diseases were at increased risk for thrombocytopenia. The potential association of clinical and clinicopathologic factors with thrombocytopenia were assessed by reviewing a series of multiple logistic regression models. Clinical and clinicopathologic variables significantly associated with thrombocytopenia in the final model included increased PCV, increased band neutrophil count, increased total WBC, and decreased plasma protein concentration. Increased mature neutrophil count was associated with normal platelet counts. Thrombocytopenic horses were significantly more likely to die or be euthanized than were horses with normal platelet counts. J Vet Intern Med 1996;10:127–132. Copyright © 1996 by the American College of Veterinary Internal Medicine .     

The microbiology and sensory evaluation of pheasants hung at 5, 10 and 15 degrees C

Pheasants hung for 9 d at 10 °G were found to be more acceptable than those hung for 4 d at 15 °G or for 18 d at 5 °G. The birds stored at 15 °G were tough by comparison with those held for longer at the lower temperatures and the clostridia, including Clostridium welchii, increased considerably in the intestines during the storage period. Microbial growth in the muscle tissue was generally found to occur only in birds in which the gut had been perforated by shot. There is an indication that 9 d at 10 °C produced a more “ gamey “ bird than 18 d at 5 °G or 4 d at 15 °G, but the most “ gamey “ birds, independent of temperature, were those in which the muscle was damaged by shot.     

Pseudoparasitism of broiler chicks by mites of the family Uropodidae, genus Fuscuropoda

Seven 6-day-old broiler chicks were presented dead and heavily infested with ectoparasites. Tentatively identified as Argas ticks, the parasites were later determined to be non-parasitic mites of the family Uropodidae, genus Fuscuropoda.     

Effects of unilateral castration and unilateral cryptorchidism of the Holstein bull on plasma gonadotropins, testosterone and testis anatomy

The effects of unilateral castration (UC) and induced unilateral cryptorchidism (CR) on plasma hormones and testis anatomy were studied in 36 Holstein bulls altered at either 3, 6 or 9 mo of age (n = 12). Plasma hormone concentrations were determined in six samples collected at hourly intervals on d 0, 1, 3, 7, 14 and 30, and then at monthly intervals through 6 mo after gonadal manipulation. Although plasma testosterone (T) showed a transient decrease (P less than .05) immediately after treatment, mean plasma concentrations of luteinizing hormone (LH) and T were unaffected by UC or CR over the 6-mo period (P greater than .05). Both hormones increased (P less than .05) in concentration with advancing age. Plasma follicle stimulating hormone (FSH) concentration was greater (P less than .05) in UC than in intact (IN) bulls overall, while FSH in CR bulls did not differ (P greater than .05) from either group. At slaughter, 11 mo after gonadal alteration, mean testis weight, ratio of testis weight to body weight and mean testis sperm cell numbers were increased (P less than .05) in UC bulls compared with mean testis values in intact (IN) bulls. Unilateral castration increased (P less than .05) seminiferous tubuler diameter and seminiferous epithelial cell height from basement membrane to the border of the lumen, but did not alter the ratio of tubuler to interstitial space within the testis. Seminiferous tubuler diameter and epithelial cell height were increased (P less than .05) in CR compared with IN bulls. Unilateral gonadal alteration at 3 mo of age caused a greater (P less than .05) hypertrophy of the scrotal testis in both UC and CR bulls than alteration at 6 or 9 mo of age. Results indicate that unilateral gonadal disruption is followed by rapid compensation in testis T production, little change in systemic LH and a rapid increase in secretion of FSH in the bull within those ages investigated. Further, UC elicits a greater compensatory hypertrophy than CR and the pituitary-testis endocrine axis is more responsive to alteration at 3 mo than at 6 or 9 mo of age in the bull.