T-2 toxin (3-hydroxy-4,15-diacetoxy-8-[3-methyl-butyrloxy]-12,13-epoxy-delta 9-trichothecene) and diacetoxyscirpenol, structurally similar trichothecene mycotoxins, in dimethylsulfoxide:saline (1:9 v/v) solvent, were given by crop gavage to 7-day-old male broiler chickens. Selected birds were killed at 1, 6, 12, 18, 24, 72, and 168 hours post-treatment. The lesions induced by the two toxins were similar, but were more severe in chicks given T-2 toxin. Necrosis of lymphoid tissue and bone marrow began one hour after treatment with T-2 toxin, and was followed by rapid cell depletion. Cell repletion also was rapid, occurring by hour 24 in mildly injured tissues from birds given diacetoxyscirpenol and by hours 72 and 168 in more severely injured tissues from chickens given T-2 toxin. Hepatic lesions were multiple foci of cell necrosis resolved rapidly and the inflammatory cell reaction was minimal. Necrosis of gall bladder epithelium and secondary cholecystitis followed hepatic cell necrosis. In the alimentary tract, necrosis of the epithelium on the tips of villi in the duodenum was followed by necrosis of the epithelium of villi and crypts in the small and large intestine, and of mucosal epithelium of the proventriculus and ventriculus. Atrophy of intestinal villi and fewer mitotic figures were seen by 18 hours after treatment. The alimentary tract epithelium, however, looked normal by hour 72. Lesions in the integument, including necrosis of feather epidermis and of the follicular epidermis at the neck of the feather follicle, occurred at 12 to 24 hours after treatment.

No abstract

An immunoperoxidase histochemical technique utilizing a monoclonal primary antibody was developed for detection of Newcastle disease virus (NDV) antigen in tissues from chickens. The technique was applied to trachea, lung, spleen, Harderian gland, and cecal tonsil harvested from specific-pathogen-free (SPF) chickens at 2, 5, 7, 10, and 14 days postinoculation (PI) with NDV, and to corresponding tissues from commercial broiler chickens representing 30 cases of spontaneous respiratory disease. Positive staining occurred in the cytoplasm of respiratory epithelial cells in the trachea or bronchi of NDV-inoculated SPF chickens at 5 and 7 days PI. Staining also occurred in the respiratory epithelium of the trachea and bronchi of commercial broilers from seven of 30 cases of spontaneous respiratory disease. These results indicate that the immunoperoxidase technique has value as a rapid diagnostic test for Newcastle disease.

A technique for early detection of tibial dyschondroplasia (TD) in live broilers was developed using the Lixiscope, a hand-held, real-time skeletal imaging device. The Lixiscope utilizes 125I gamma energy (27 keV), which is converted to electrons and then to visible energy, for imaging by way of an output phosphor or electron-to-photon conversion. Image amplication is 45,000 to 50,000 times, and image resolution is 4.2 line pairs per millimeter. The left and right tibiotarsi of the parent stock of male broiler breeder chickens were examined at 3, 4, 6, and 8 weeks of age. The images readily allowed for the detection of TD. A scoring system was established to assess severity of TD and was confirmed accurate as correlated with direct radiography and macroscopic examination at necropsy. This technique offers a quick, non-invasive, early detection of TD in broilers. The equipment is portable and can be used in field selection procedures.

Cryptosporidia were found in the respiratory tract of turkeys in eight flocks on five different farms over a 4-month period. Turkeys ranged in age from 2 1/2 weeks to 11 weeks of age. All had respiratory signs. Diagnoses were made by examining wet smears and confirmed by histopathological examinations.