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Milk from sows whose progeny developed post weaning E. coli diarrhoea (PWD milk) and from sows which were immunized by intramuscular vaccination using a homologous strain of E. coli (immune milk) were tested in ligated segments of pig intestine. The results showed that PWD milk neutralized the enterotoxigenic, fluid accumulating capacity of the lysate of the disease-causing E. coli pathogen. A similar effect was seen by using immune milk (Table I). Neither PWD milk nor immune milk contained sufficient antibacterial activity to neutralize the fluid accumulating capacity of live cultures of E. coli O149:K91, while such activity was contained in immune serum. It is concluded that milk from sows whose progeny developed PWD contains antibodies capable of neutralizing the enterotoxigenic effects of the homologous E. coli organisms. It is suggested that the presence in milk from these sows of antibody-mediated activity against enteropathogenic E. coli organisms may be instrumental in preventing the disease in the progeny during the suckling period and consequently, when this protective milk supply stops at weaning, the disease may develop in susceptible animals, mainly because their own production of specific E. coli antibodies is insufficient to prevent PWD.  相似文献   

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Beef production comprises about 40% of the budget for the 3-year common programme of research in the European Economic Community, granted in 1975 for funding by the Commission. In addition, a full co-ordination programme of seven seminars was held in 1975/1976 on aspects of beef research closely connected with the common programme. The results of about 200 papers and discussion sessions provide a summary of the genetic, nutritional and management aspects of beef production in the Community and some of the research in progress. Many avenues for increased production or improved efficiency of conversion of feed to beef were examined. A survey of breeds and feeds was made; cross-breeding was studied and research on nutrition was reviewed. Methods of increasing the number of calves for beef production were discussed, viz. by egg transfer, by reducing perinatal ill-health, and by the early calving of heifers. An approach to improved efficiency of use of animal and land resources for milk and beef production emerged in terms of the more effective utilisation of the 80 million cattle of the Community and of its crops and by-products. The needs for future research and the common programme of research are briefly described.  相似文献   

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