Brachiaria decumbens was fed as exclusive source of food to feedlot sheep. Sheep were evaluated in three periods of the year, of 60 days each, regarding their clinical status and was performed collection of blood samples to measure enzymatic activity of gamma glutamyltransferase and aspartate aminotransferase to evaluate their diagnostic importance and usefulness besides the clinical signs, necropsy and histopathology finds in hepatogenous photosensitization Brachiaria related. Out of 24 feedlot sheep, five died in the first period (February-April), four in the second (June-August) and two in the third (October-December). Main clinical signs were anorexia, jaundice, photophobia and two cases of slight dermatitis, besides dehydration, apathy and corneal opacity. Necropsy revealed generalized jaundice, distended gall bladder and liver with evident lobular pattern. The histological changes varied in severity according the time after the beginning of the plant ingestion; they were more significant in the liver and included bilestasis, swelling and vacuolation of hepatocytes, foammy macrophages, bile duct proliferation and mononuclear inflammatory cell infiltration, further crystal negative images were found within cytoplasm of macrophages present inside of hepatic sinusoid and in the periportal space and also optically active refringent crystal in the lumen of bile tubules. These finds are characteristic of hepatogenous photosensitization, mainly by presence of photophobia, even when the sheep did not present photodermatitis. The results of serum biochemistry activity, during the course of poisoning with strong relation between increased gamma glutamyltransferase activity, and lethality. Onset of arising gama glutamyltransferase activity was 11 days, in average, before beginning of clinical signs. Aspartate aminotransferase had increased activity only close to the beginning of clinical signs. Serum biochemistry results of GGT suggest that they are useful for a precocious diagnosis preventing deaths caused by ingestion of B. decumbens. Thirteen sheep didn't show clinical signs despite significant increases on serum enzyme activity, suggesting the existence of tolerant/resistant individuals. The experimental model of feedlot was adequate to study B. decumbens toxicosis in sheep.INDEX TERMS: Brachiaria decumbens, photosensitization, sheep, pathology, feedlot.

ABSTRACT.-Porto M.R., Saturnino K.C., Lima E.M.M., Lee S.T., Lemos R.A.A., Marcolongo--Pereira C., Riet-Correa F. & Castro M.B. 2013 Twenty-six five-month-old lambs originated from flocks with no previous contact with Brachiaria spp. pastures were divided into three groups. Two groups (GS and GSB) were fed daily with fresh harvested Brachiaria decumbens ad libitum. GS was kept in an area with solar exposure and GSB was kept in stalls sheltered from solar exposure. Control group (GC) was also kept under solar exposure, but fed with Cynodon dactylon grass hay and Pennisetum purpureum fresh grass. All sheep from the three groups were supplemented with 200g daily of a commercial concentrated food. Evaluation of clinical signs was carried out daily and blood samples were collected twice a week to determine AST and GGT serum activities. Three out of nine lambs of GS presented clinical signs of Brachiaria spp. poisoning, and two died. One animal showed clinical signs and died in GSB. The main clinical signs observed were apathy, weight loss, photophobia, conjunctivitis, ocular mucous discharge and jaundice. Dermatitis due to photosensitization was not observed. Mean serum AST and GGT activities were significantly higher (p≤0,05) in the group exposed to sun, than in the other two groups, and the GGT activities were significantly higher in the group sheltered than in the control group (p≤0,05). All animals at the end of the experiment were submitted to liver biopsy and died lambs were necropsied. Histopathological evaluation of liver samples from sheep with clinical signs evidenced swelling and vacuolization of hepatocytes, individual hepatocytes necrosis, presence of foamy macrophages, crystal negative images within bile ducts and foamy macrophages, biliary duct hyperplasia and periportal mononuclear infiltration. These results suggest that sun exposure does not define intoxication, but exacerbates the toxicity of the grass. RESUMO.-Foram utilizados 26 ovinos, entre 3 e 4 meses de idade, divididos em 3 grupos, provenientes de rebanhos que nunca tiveram contato com pastos de Brachiaria spp.. Dois grupos receberam Brachiaria decumbens no cocho diariamente ad libitum, sendo que um deles permaneceu em área com exposição solar (GS) e o outro foi mantido em baias cobertas protegidos do sol (GSB). O grupo controle (GC) foi também mantido em local com exposição solar e alimentado com feno de Cynodon dactylon e capim Pennisetum purpureum triturado. Todos os grupos receberam alimentação em cochos e foram suplementados com 200g/ dia/animal de ração comercial para ovinos. Foi realizada a avaliação clínica diária dos ovinos e colhidas amostras duas vezes por semana para dosagem sérica de AST e GGT. Os

This study aimed to characterize the liver histology and histomorphometry in sorubim hybrid of different categories (nursery, growth and grow-out) reared on fish farming. The categories were defined considering body weight (BW): nursery category (n = 5): BW = 37.06 AE 6.00 g (31.6-45.3 g); growth category (n = 5): BW = 310.40 AE 53.80 g (242.1-376.4 g) and grow-out category (n = 5): BW = 874.28 AE 27.59 g (846.2-913.1 g). Liver fragments were processed to paraffin inclusion, and sections were stained by haematoxylin and eosin (H&E), PAS (Periodic Acid Schiff) and Perl's staining to histology, histomorphometry and density volumetric of liver structures; glycogen analysis and to detect ferric irons (Fe 3+ ) respectively. The hepatosomatic index decreased between the categories (P < 0.01). The percentage of PAS-positive hepatocytes in the nursery category was higher (P < 0.05) in relation to the growth and grow-out categories. The hepatocytes from all fish were positive to Perl's staining. The density volumetric of liver structures did not differ among categories except to blood vessels were higher (P < 0.01) in the nursery and growth. The area (lm 2 ) and perimeter (lm) of hepatocytes, and the area (lm 2 ), perimeter (lm) and volume (lm 3 ) of the nuclei from grow-out fish were lower (P < 0.01) than those from the nursery and growth categories. Changes in morphometric characteristics of hepatocytes may result from metabolic changes associated with body growth surubins; therefore, these morphometric characteristics of liver tissue can be used as functional biomarkers for the assessment of fish health and nutrition status.

PURPOSE:To establish a model of chronic kidney disease in White New Zealand rabbits, using an exclusive unilateral technique of renal ischemia and reperfusion. METHODS:Twenty males White New Zealand rabbits were used. All animals were subjected to the following: pre-surgical blood collection (1 st collection) for creatinine and urea serum analysis, left renal ischemia and reperfusion surgery technique, another blood sample was collected after 6 weeks post surgery (2 nd collection), the last blood sample (3 rd collection) blood sample was taken 11 weeks post surgery (pre-euthanasia), euthanasia and withdrawal of right and left kidney for histopathological analysis. RESULTS:The creatinine levels after surgery was statistically significant higher in the 3 rd collection, regarding the 1 st and 2 nd collection (p<0.05). A significant statistic increase for urea was showed only in the 2 nd collection (p<0.05) when compared to the 1 st and 3 rd collections. Histopathological analysis showed bilateral lesions in the renal tissue, consistent to the process of ischemia and reperfusion. CONCLUSION:This exclusive unilateral technique of renal ischemia and reperfusion without nephrectomy in White New Zealand rabbits, showed effectiveness in getting an animal model of chronic kidney disease