Noadswood Science, 2012

 To understand how farming methods can increase food production Monday, September 07, 2015

 This animal has eaten 100 kJ of stored energy in the form of grass, and excreted 63 kJ in the form of faeces, urine and gas and the energy stored in its body tissues is 4 kJ – how much has been used up in respiration?  Energy taken in = 100KJ  Energy transferred to tissues + faeces etc… = 63KJ + 4KJ = 67KJ  Energy released by respiration = 100KJ – 67KJ = 33 kJ  Only 4 kJ of the original energy available to the animal is available to the next stage – the efficiency of this energy transfer is: - Efficiency = (4KJ ÷ 100KJ) × 100 = 4%

 Food production is more efficient if the food chain is short, because a higher percentage of energy is available…

How can the efficiency of food production be improved?  Reduce the number of stages in the food chain  Restrict the energy lost by the farm animals

Reducing the number of stages in the food chain improves efficiency: -  For a given area of land a greater amount of food can be grown in the form of crops rather than animals  This is because the number of stages in the food chain is reduced  There are some problems with this: demand for meat is high; some land cannot be used for crops; and people need a varied diet to stay healthy

Food Chains

Energy lost by the farm animals can be reduced via intensive farming: -  Animals are kept close together indoors so they are warm and cannot move about  This saves them wasting energy on movement and reduces their heat loss  This makes the transfer of energy from the animal feed to the animal more efficient (the animal grows faster on less food)

There are a great deal or moral issues surrounding intensive farming: -  Cruel to force livestock to live in unnatural and uncomfortable conditions  Disease is common place and prevention of this results in antibiotics given to livestock which can results in microbe immunity to the antibiotics  Maintaining the heated environment uses fuel  Fish stocks are reduced as often these are used within the animal feed

Overfishing  Overfishing is causing severe problems with many fish stocks in the oceans – this has a massive impact on a huge number of food chains…  Sustainable food production with fish is intended to keep fish stocks at a level where fish continue to breed and occurs via: -  Fishing quotas – limits on the number and size of fish to be caught in certain areas  Net size – reduces ‘unwanted’ and then discarded fish being caught (and allows longer fish which are smaller to slip through allowing them to reach breeding age)

Mycoprotein  Mycoprotein is a protein from fungi – it is used as a meat substitute, such as Quorn  It is made from a fungus called Fusarium using glucose syrup as food (via enzymes digesting maize starch)  Mycoprotein has some real advantages, including allowing protein to be manufactured much more cheaply (the fungus does not require much room / grows quickly / can even ‘feed’ on waste / no large animals are killed)

 What is your opinion on intensive farming – is this a good thing, or should we all be eating natural organic food?  Discuss both intensive and organic farming methods, and produce a pamphlet containing a balanced viewpoint of both practices  Consider: -  Livelihood of the animals  Cost  How much food do we have  Potential for antibiotic resistance in humans  Environmental costs  Developing world needs  Etc…