Acta veterinaria Scandinavica. Supplementum最新文献

This review describes some circumstances where endotoxins of gram negative bacteria may be related to the pathogenesis of some common production diseases. Decisive evidence for the pathogentical role of endotoxins remains scarce, and therefore an interdisciplinary background covering epidemiological, biological, biochemical, clinical and experimental aspects is given. Several authors have suggested that endotoxins play a significant role for the development of diseases such as laminitis, abomasal displacement, sudden death syndrome of feed-lot steers etc. While the biological, biochemical and clinical pictures of bovine endotoxicosis is quite well known, and certainly may resemble the clinical and biochemical pictures seen in some of the before mentioned diseases, it is however still not clear how or when endotoxins would gain parenteral access. This review describes excerpts of the biology of endotoxins, key clinical signs and the biochemistry associated to these. It is described how ruminal acidosis may facilitate the translocation of endotoxin from the intestinal/ruminal contents to the portal and eventually the systemic bloodstream. The function of the liver hence becomes central, and the role of hepatic fatty infiltration around parturition is discussed. The review finally suggest that acute ruminal acidosis may be viewed as an analogue to the human syndrome Gut-Derived Infectious Toxic Shock (GITS), where shock is propagated primarily by the translocation of bacterial endotoxin from the gut.

Bone metabolism in humans and several animal species can be monitored in vivo by measuring enzymes and other protein products released by osteoblasts and osteoclasts, respectively. Bone mineral density (BMD) and content (BMC) can be determined by peripheral quantitative computer tomography (pQCT). Another approach is to measure histomorphometric indices of bone biopsies. The biochemical markers of bone formation currently in use include bone isoenzyme of alkaline phosphatase, osteocalcin and propeptides derived from the N or C terminal ends of the type I procollagen molecule. The longest established method for the measurement of bone resorption is hydroxyproline in urine. However, it is not specific for bone, since it is found in all collagen types and it can also derive from the diet. The most useful markers of bone resorption are breakdown products of type I collagen. The measurement of collagen crosslinks, deoxypyridinoline and pyridinoline, is comparatively more specific to monitor bone resorption. Deoxypyridinoline and pyridinoline are of use in human medicine in the diagnosis and evaluation of bone diseases and in the prediction of the occurrence of fractures and the rates of bone loss. The carboxyterminal telopeptide of type I collagen, which has been used in several animal species, is also a promising bone resorption marker. This overview gives a general idea about the use of different bone markers and measurements of other bone parameters in ruminants during growth, gestation and lactation in relation to calcium metabolism.

The objective of the present study was to investigate the milk fever preventive strategies used by a representative group of Danish Milk Producers (MP). A telephone interview was performed in 1999. A total of 230 MPs were called and asked about how they prevented milk fever in the previous year. Three interviewers performed these interviews. The study was completed within 2 1/2 months. A total of 184 MP (80%) completed the telephone interview. Of these, 149 (81%) indicated to use an active effort to prevent milk fever. In the single animal, the preferred strategy was per oral drenching with calcium containing products around calving. The convenience of application of the product was the most decisive single factor. In groups of animals feeding strategies (preferably diets low in calcium) were prioritized. Management (for example preventing fat cows at calving) was used frequently as preventive tool against milk fever. The Danish MP uses internationally documented milk fever preventive strategies, but some empirical management factors seem to count as much as the scientific proven methods.

This article summarizes the results obtained in 6 separate studies concerned with the effect of zeolite A supplementation in the dry period on blood calcium, magnesium and phosphorus status around calving. The experiments were conducted on 5 different farms, and comprised a total of 117 cows. Two of the experiments (exp. 5 and 6) were conducted under extensive farming conditions whereas the rest (exp. 1-4) were conducted on intensively driven farms. All cows included in the experiments had completed at least 2 lactations. The cows were allocated as either untreated control cows or zeolite treated experimental cows according to expected date of calving and parity. The experimental cows were fed between 0.5 and 1.0 kg of zeolite A per day during the last 2 to 4 weeks of the dry period. Blood samples were drawn on the day of calving and day one and two after calving (all experiments), three weeks before the expected date of calving (exp. 1 and 2) and one week after calving (exp. 3 and 4). The zeolite supplementation significantly increased the mean serum Ca level on the day of calving. The efficiency of the zeolite supplementation to prevent hypocalcaemia (serum Ca < 2.00 mmol/l) on the day of calving was calculated. Efficiencies varied ranging from 3 to 100%, with a mean efficiency of 58%. The zeolite-calcium ratio (g of zeolite per cow per day/g of dietary calcium per cow per day) was calculated in each experiment. From the results it seemed, that zeolite-calcium ratios below 5 did not effectively prevent parturient hypocalcaemia, whereas ratios of 10 to 20 proved very efficient in preventing hypocalcaemia. There was apparently no additional effect from feeding zeolite for 4 instead of 2 weeks prepartum. Feeding zeolite in the dry period significantly decreased plasma phosphate before as well as after calving. The phosphate level was normalized within one week after calving. Plasma magnesium was significantly lower among the experimental cows on the day of calving, but stayed within the normal range of plasma magnesium. The control cows on the other hand experienced hypermagnesemia after calving.

Dogs and horses are transported within the European Union for a number of reasons. The transport per se may cause physical problems, exemplified by hyperthermia in dogs and pleuropneumonia in horses, and the stress may reactivate latent infections such as canine herpesvirus-1 and equine herpesvirus-1. Preventive treatments are vital to protect dogs from ticks and mosquitoes transmitting their potentially lethal infectious agents, such as Leishmania donovani infantum, Babesia canis, Ehrlichia canis, and Dirofilaria immitis. However, records show that the travelling dogs are not fully protected since cases occur in non-endemic regions. The brown dog tick also poses a risk for humans by transmitting Rickettsia conorii causing Mediterranean spotted fever. Further, the trade in stray dogs from southern Europe has placed a particular focus on the occurrence of vector-borne diseases in the Mediterranean basin. The unknown origin of strays also poses a risk for rabies. With respect to horses, those transported to southern Europe may be exposed to Theileria equi and Babesia caballi, both of which are transmitted by ticks. Horses with antibodies against these parasites are not permitted to enter the USA. Additionally, viral diseases such as African horse sickness, transmitted by midges, and Borna disease, of the mode of transmission is yet unclear, may also pose a risk for horses travelling to potentially endemic regions.