RESUMO
Bone fractures are a frequent cause of limp in cattle, being pre-existing bone lesions among the predisposing factors. However, there is scant information about the natural occurrence of bone disease. This report aimed to describe an outbreak of spontaneous fractures associated with hypocuprosis in pen-backgrounded calves. Hind limp and irreversible recumbency were noticed in 9-month-old calves of a dairy farm from Córdoba province (Argentina). The issue was only evident in males fed a diet composed (DM) of 57% wet corn, 24% dry corn distiller grains, and 19% corn silage. No mineral mix was supplied. Accumulated morbidity and fatality rates were 5.8 and 100%, respectively. Two autopsies were performed, observing multiple femoral and rib fractures. Severe hypocupremia, very low copper levels in the liver and plasma, deficient dietary copper levels, normocalcemia, marginal hypophosphatemia, and high sulfate concentrations in the water supply were determined. Except for the decreased bone quantity and the multiple fractures, no bone lesion was observed, confirming osteoporosis as the pathological diagnosis, and hypocuprosis as the etiology.(AU)
Assuntos
Animais , Osteoporose/veterinária , Bovinos/lesões , Fraturas Espontâneas/diagnóstico , ArgentinaRESUMO
Sulphur (S) dietary excess can limit productive performance and increase polioencephalomalacia (PEM) incidence in feedlot cattle (FC). Sulphur excess ingested is transformed to hydrogen sulphide (H2 S) by sulfo-reducing ruminal bacteria (SRB), being high ruminal H2 S concentration responsible for aforementioned damages. As the ruminal mechanisms involved in H2 S concentrations increase have not been elucidated, this study aimed to evaluate the ruminal environment, and the association between ruminal H2 S and dissimilatory SRB (DSRB) concentration in FC experimentally subjected to S dietary excess. Twelve crossbred steers were randomly assigned to one of two dietary S levels (6 animals per treatment): low (LS, 0.19% S) and high (HS, 0.39% S obtained by sodium sulfate inclusion at 0.86%). The study lasted 38 days, and on days 0, 22 and 38, ruminal gas samples were taken to quantify H2 S concentration, and ruminal fluid to determine total bacteria, DSRB, protozoa, volatile fatty acid and ammonia nitrogen concentration. For ruminal H2 S concentration, S dietary × sampling day interaction was significant (p < 0.001), so that the greater concentration was observed on days 22 and 38 with the HS diet. The remaining ruminal parameters were not affected by dietary S level, and no significant correlation between H2 S and DSRB concentrations was observed. The ruminal adaptation that maximizes H2 S production in FC consuming S excess does not seem to be associated with biological or biochemical alterations, nor DSRB concentration changes. The microbial diversity and ruminal environment were resilient to the S excess evaluated, suggesting that 0.39% of dietary S achieved by 0.86% sodium sulfate addition, could be used without disturbances on digestion nor health of FC.
Assuntos
Ração Animal , Rúmen , Ração Animal/análise , Animais , Bovinos , Dieta/veterinária , Digestão , Ácidos Graxos Voláteis/metabolismo , Fermentação , Rúmen/metabolismo , EnxofreRESUMO
We report an outbreak of bovine paralytic rabies in a feed lot in a disease-free area in southern Santa Fe, Argentina. Six of 122 unvaccinated steers died after showing neurological signs (morbimortality = 4.9%) for 24-72 hours, 40-75 days after being transported to the feed lot from a farm located in Formosa. Pathologic examination of the brain in 3 steers revealed gliosis, lymphoplasmacytic meningoencephalitis, and intracytoplasmic inclusion bodies in neurons, along with intralesional detection of the rabies virus antigen by immunohistochemistry in 2 cases. Rabies virus was confirmed by direct immunofluorescence in the brain, and further identified as variant 3a, typical of hematogenous bats, by inoculation in mice followed by indirect immunofluorescence. This represents the first communication of bovine paralytic rabies described in the Pampas plain in Argentina, and evidences that the transport of cattle from endemic to disease-free areas could represent a mechanism of dissemination of this communicable zoonotic disease.