Biodiversity, Stress and Food Safety

Natural Farming - Photo Keith Webber Jr

Biodiversity, Stress and Food safety

'Biodiversity' is the word that we use when we talk about the 'variety of living things'. This diversity is essential to our health, prosperity and well-being.

If we are to understand the complexity we must know its building blocks, we must understand its variety, its biodiversity. We must also understand how different species relate to each other both in their interaction as living organisms (e.g. the interaction of insects and flowering plants) and in their evolutionary histories.

The starting point of animal-welfare is the recognition that animals are sentient beings and should be treated in such a way that they do not suffer unnecessarily. It concerns the animals that are under human care {e.g. on the farm, during transport, or at the time of slaughter}.

All farm animals will experience some level of stress during their lives. Stress reduces the fitness of an animal, which can be expressed through failure to achieve production performance standards, or through disease and death. Stress in farm animals can also have detrimental effects on the quality of food products. However, although a common assumption of a potential effect of stress on food safety exists, little is actually known about how this interaction may occur.

Colonization of farm animals by enteric pathogens such as Escherichia coli O157:H7, Salmonella, and Campylobacter, and their subsequent dissemination into the human food chain are a major public health and economic concern for the food industries. Stress can have a significant deleterious effect on food safety through a variety of potential mechanisms. However, as the impact of stress is difficult to precisely determine, it is imperative that the issue receives more research attention in the interests of optimizing animal welfare and minimizing losses in product yield and quality, as well as to food safety risks to consumers.

While there is some evidence linking stress with pathogen carriage and shedding in farm animals, the mechanisms underlying this effect have not been fully elucidated. Understanding when pathogen loads on the farm are the highest or when animals are most susceptible to infection will help identifying times when intervention strategies for pathogen control may be most effective, and consequently, increase the safety of food of animal origin.

Reducing stress on animals has been demonstrated to improve productivity and prevent physiological changes.

All livestock are herd animals, and they are likely to become highly agitated and stressed when they are separated from their herd mates. Groups of animals that have body contact remain calmer. Reducing stress also should help improve weight gain, reproductive performance and animal health.