Asunto(s)
Ciervos , Brotes de Enfermedades/veterinaria , Micotoxicosis/veterinaria , Intoxicación por Plantas/veterinaria , Poaceae/microbiología , Alimentación Animal , Animales , Micotoxicosis/epidemiología , Micotoxicosis/etiología , Intoxicación por Plantas/epidemiología , Intoxicación por Plantas/etiología , Victoria/epidemiologíaRESUMEN
It is difficult to identify mineral deficiencies and even harder to predict their occurrence. The best indicators of a particular disorder are the characteristic clinical signs. In their absence, biochemical tests or well-designed and properly conducted dose-response field trials are the only sure ways of defining deficient states and assessing their functional and economic significance. This article identifies treatments of the main mineral disorders in cattle and preventive strategies to minimize their occurrence. Dietary manipulations or oral treatments are indicated for chronic primary deficiencies in which there is insufficient mineral in the diet to meet cattle requirements. In severe and acute deficiency, parenteral treatment restores normal concentrations rapidly to a functional level in the animal's tissues. Advocate parenteral treatments if alimentary absorption is impaired or at times of increased mineral demand, such as late pregnancy, but be wary of toxicity. Many innovative products and delivery systems are now available for relatively cheap, effective, long-term mineral supplementation with minimal handling of cattle.
Asunto(s)
Enfermedades de los Bovinos/terapia , Enfermedades Carenciales/veterinaria , Animales , Calcio/deficiencia , Bovinos , Cobre/deficiencia , Enfermedades Carenciales/terapia , Femenino , Deficiencia de Magnesio/terapia , Deficiencia de Magnesio/veterinaria , Fósforo/deficiencia , Embarazo , Complicaciones del Embarazo/terapia , Complicaciones del Embarazo/veterinaria , Selenio/deficienciaRESUMEN
The aim of this study was to determine whether evidence could be obtained of foetal infection with Leptospira interrogans serovar hardjo in aborted foetuses collected from dairy farms. Material from 197 abortions occurring over a wide area of Victoria was collected over 3 years. None of 195 foetal kidney cultures or 7 cultures from membranes was positive for leptospiral organisms. Immunogold silver staining for leptospires was performed on sections of kidneys, lungs or heart from 156 foetuses, with negative results. Evidence of transient leptospiral infection in 11 of 123 foetuses was obtained by foetal heart blood serology. Two isolates of L. interrogans serovar hardjo were obtained from the urine of milking cows. These strains were examined by restriction endonuclease analysis and both were shown to be of the genotype Hardjobovis, as have been all Australian isolates studied so far. It appears that foetal infection with serovar hardjo is not associated with any substantial proportion of bovine abortions in Victoria, in contrast to the situation in Northern Ireland. The apparent absence from Victoria of the pathogenic genotype Hardjoprajitno is a possible explanation.