Infectious stunting syndrome: evidence of vertical transmission

Day-old broiler chicks were collected while in transit from a hatchery to a farm and reared in isolation. These chicks did not develop clinical signs of infectious stunting syndrome. When they were 14 days old, susceptible day-old chicks were placed in contact with them and these subsequently developed typical signs and lesions of the disease.     

Discriminant analysis for predicting dystocia in beef cattle. II. Derivation and validation of a prebreeding prediction model

Discriminant analysis was utilized to derive and validate a model for predicting dystocia using only data available at the beginning of the breeding season. Data were collected from 211 Chianina crossbred cows (2 to 6 yr old) bred to Chianina bulls. A proportionally stratified sampling procedure divided females into an analysis sample (n = 134) on which the model was derived and a hold-out sample (n = 77) on which the prediction model was validated (tested). Variables available during the derivation stage were cow age, cow weight, pelvic height, pelvic width, pelvic area and calf sire. Dystocia was categorized as either unassisted or assisted. Occurrence of dystocia was 17.2 and 18.2% in the analysis and hold-out samples, respectively. All data were standardized to a mean of zero and a variance of one before statistical analysis. The centroid of cows experiencing dystocia differed (P less than .01) from that of cows calving unassisted in the analysis sample. Significant variables were pelvic area and cow age (standardized coefficients = .56 and .51, respectively). This model correctly classified 85.1% of the cows in the analysis sample. This was 13.5% greater than the proportional chance criterion. For model validation, prediction accuracy was 84.4% in the hold-out group, which was 14.2% greater than the proportional chance criterion. However, only 57.1% of the cows that experienced dystocia were correctly classified. Examination of the data revealed that those cows misclassified were 3 yr of age or older.(ABSTRACT TRUNCATED AT 250 WORDS)     

Diseases diagnosed in broiler chicken flocks in Victoria, Australia, 1977 to 1984

During the period July 1977 to June 1984, specimens from 1402 broiler chicken flocks were submitted to the Veterinary Research Institute, Victoria, Australia for investigation of morbidity, mortality and, or, poor performance. A total of 19,450 post mortem examinations, as well as numerous ancillary tests, were performed. The findings on these flocks are presented and the consequences of some particular diseases noted.     

Correlative biomechanical and histologic study of the cranial cruciate ligament in dogs

The mechanical properties of the cranial cruciate ligament were determined, using unilateral bone-ligament-bone preparations from 65 dogs of various ages and body sizes. Tensile loading of the cranial cruciate ligament from 1 of each pair of stifle joints demonstrated a decrease in material properties (modulus, maximum stress, strain energy) with aging. The decreases in maximum stress and strain energy with age were significantly less (P less than 0.05 and P less than 0.05, respectively) in the cranial cruciate ligament from dogs weighing less than 15 kg, compared with those weighing 15 kg or more. The cranial cruciate ligament and remaining femorotibial ligaments were collected from the opposite stifle joints and examined microscopically. By 5 years of age, the cranial cruciate ligaments of dogs weighing greater than 15 kg consistently had microscopic evidence of degenerative disease (loss of ligamentocytes, metaplasia of surviving ligamentocytes to chondrocytes, and failure to maintain collagen fibers and primary collagen bundles) which progressed in severity with age. The caudal cruciate ligaments were similarly affected, although the degenerative changes were rarely as severe as in the cranial cruciate ligament. The collateral ligaments underwent minimal degeneration. Sex differences had no bearing on degeneration. The cranial cruciate ligaments in dogs weighing less than 15 kg generally had less severe alterations than those in heavier dogs, and the onset of the degenerative process was delayed by several years. Cranial cruciate ligaments removed from dogs after ligament failure not only had degenerative disease, but also had undergone unsuccessful attempts at repair. In contrast, fibrous repair was rarely present in intact ligaments of asymptomatic dogs with degenerative disease of the cranial cruciate ligament.     

Isolation and identification of Aegyptianella pullorum (Rickettsiales, Anaplasmataceae) in wild turkeys from North America

Isodiagnosis of blood from Rio Grande wild turkeys from southern Texas revealed a small, intraerythrocytic rickettsia, Aegyptianella pullorum Carpano, 1928, in 24 of 300 samples. Identification of this first isolate from North America was made using both light and transmission electron microscopy. It is suggested that the translocation of wild turkeys from Texas to other states could spread this pathogen to both wild birds and domestic poultry.     

Nonsurgical removal of a catheter embolus from the heart of a dog

A fragment of an 18-gauge catheter was inadvertently severed during catheterization of the cephalic vein in a 7-year-old Golden Retriever. Under fluoroscopic guidance, the fragment was retrieved successfully from the right ventricle, using a self-constructed, loop-snare catheter.     

Utilization by sheep of whole shelled corn impregnated with urea, calcium, potassium and sulfur

Twenty-eight growing wether lambs (33.9 kg), adapted to urea for 40 d, were used in a metabolism study to determine if urea impregnation of corn could improve urea utilization. The following diets were compared: 1) whole shelled corn alone, 2) whole shelled corn impregnated with urea, calcium (Ca) as CaCl2, potassium (K) as KC2H3O2, and sulfur (S) as Na2S2O3 X 5H2O, 3) whole shelled corn fed with a dry supplement containing urea, Ca, K and S and 4) whole shelled corn fed with a dry supplement containing soybean meal, Ca and K. Additions were made to provide diets containing 12% crude protein, .37% Ca and .50% K. A 10:1 N (from urea) to S ratio, dry basis was used in urea-containing diets. Corn (90% dry matter) in diet 2 was impregnated by spraying 1.1 liters of an aqueous solution containing the above salts per 10 kg of corn dry matter. After mixing for 10 min in a horizontal mixer, the corn was dried in a laboratory grain drying bin with ambient laboratory air for 48 h. Lambs were fed 350 g of the respective diets plus 35 g orchardgrass hay twice daily during a 20-d metabolism trial. On the last day of the trial, ruminal fluid samples were collected at 0, 1, 2, 3, 4, 5 and 6 h postfeeding and jugular blood was obtained at 0 and 6 h postfeeding. Nitrogen-supplemented diets resulted in increased (P less than .01) absorption and retention of N. Digestibility of dry matter, organic matter and NFE tended to be greater in lambs fed impregnated corn than in lambs fed the other diets.(ABSTRACT TRUNCATED AT 250 WORDS)     

Mitogenic responses of baboon (Papio cynocephalus) peripheral blood mononuclear cells. A possible role for monocytes

Removal of carbonyl iron-adherent/phagocytic cells from baboon peripheral blood mononuclear cells generally resulted in a depressed blastogenic response to both pokeweed mitogen and concanavalin A. In the majority of cases, no alteration in dose requirement nor shift in kinetics was apparent. Staining for peroxidase activity indicated a reduced proportion of monocytes in the population of cells treated with iron. Therefore, the results of this study strongly suggest a potentiating role for monocytes in lectin stimulation of baboon lymphocytes.     

Induction of diplodiosis, a neuromycotoxicosis, in domestic ruminants with cultures of indigenous and exotic isolates of Diplodia maydis

Diplodiosis, a neuromycotoxicosis, principally of cattle, which is characterized by ataxia, paresis and paralysis, was induced in 13 cattle, 16 sheep and 3 goats, by dosing them with Diplodia maydis [= D. zeae (Schw.) Lév.] cultured on sterilized maize seeds. The results of these experiments confirmed the findings of earlier workers that diplodiosis is a mycotoxicosis caused by D. maydis. The intoxication was induced with cultures of South African isolates of D. maydis obtained from local maize, one of which was associated with a suspected field outbreak, and with cultures of isolates from maize imported from the United States of America and Argentina. Other findings emerging from the experiments were, inter alia, that cultures incubated for less than 8 weeks were seemingly non-toxic, that there was little individual variation in response of cattle to cultures of the different toxic isolates or batches of the isolates, that apparent relapses of clinical signs can occur several weeks after dosing had ceased and that a small percentage of animals can show permanent locomotory disturbance. Light microscopical examination revealed no lesions in acutely affected animals, but an extensive laminar subcortical status spongiosis was evident in the cerebrum and cerebellum of a sheep that had been long paralysed and a steer that had permanent locomotory disturbance.     

Occipito-atlanto-axial malformation with atlanto-axial subluxation in an ataxic calf

Occipito-atlanto-axial malformation with atlanto-axial subluxation was diagnosed radiographically in a 4-day-old Holstein calf with a short neck, symmetric ataxia, and tetraparesis, indicative of a cervical spinal cord lesion. Necropsy confirmed the clinical diagnosis and revealed ribs on C-7, with partial fusion of C-7 and T-1. Histologic examination revealed focal degeneration of the spinal cord in the second cervical segment at the level of the atlanto-axial joint and extensive secondary neuronal fiber degeneration possibly caused by spinal cord trauma that occurred in utero.