科研之友
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摘要
The recent increase in free-range meat and egg production and consumption has led to extensive investigation in this area and has revealed that the level of animal performance achieved in such systems is low compared with that achieved in conventional production systems. In Australia, this difference has been attributed either to the absence of in-feed antibiotics or to range access, which may result in exposure to detrimental climatic conditions, predators, disease, welfare challenges and nutrient dilution. Moreover, although poultry in free-range systems have ready access to outside runs, not all birds utilise them optimally. Pasture consumption results in dilution of energy and protein intake and may cause impaction and dietary electrolyte imbalance. This paper provides an overview of these issues to provide a conceptual framework for further study in this area.
- 出版日期2013
