Science & Technology in Action

9th Edition

The Bovine Genome and Human Nutrition

Teagasc

Food quality is important for both human health and Irish export sales. Genomic analysis of cattle, as carried out by the ICBF, allows scientists to design specific breeding regimes and to predict the quality of beef and milk. This lesson deals with human nutrition, cattle breeds in Ireland, the impact of genomic science and genomic profiling.
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Contains the full lesson along with a supporting toolkit, including teachers’ notes.

Lesson excerpt

Human nutrition
Living processes require energy and so the most basic function of food is to supply us with energy – typically 8 to 12 MJ (million joules) per day (equivalent to 2000 to 3000 kilocalories per day), depending on a person’s general activity level.

Our energy requirement is met mainly by carbohydrates. However, a human being would not survive on a diet of sugar alone. Our diet should also contain water, protein, fat, and small amounts of certain minerals and vitamins. It is also desirable to include a certain amount of roughage in the diet.

1 kcal = 4184 J = 4.184 kJ;
1 kilocalorie is often written as 1 Calorie (with a capital ‘C’)

Average human daily requirements
A balanced daily diet should provide about 10 MJ of energy, about 70 g of protein and about 20 g of fat, as well as essential micronutrients (i.e. minerals and vitamins). Bread, potatoes and rice contain 30% to 50% starch (a carbohydrate) and could supply most of the energy requirement. The nutritional components of some common foods are shown in the table.

Cattle breeds in Ireland
In Ireland there are about 5 million beef cattle and 1.4 million dairy cows. The annual beef output is approximately 500,000 tonnes, 90% of which is exported – mainly to the UK. The annual milk output is about 6 billion litres, 85% of which is exported as milk or dairy products.

Quiz questions

  1. Genomic analysis can help improve the traceability of meat. true
  2. Cattle and humans are the only organisms whose genome has been determined. false
  3. The genetic diversity of cattle has increased since they were first domesticated. false
  4. The cow genome has approximately 22,000 genes. true
  5. Determination of all protein functions in a cell is a slower process than establishing its genome. true
  6. Success rates in producing transgenic cattle are currently fairly low. true
  7. Knowing genomes and proteomes can help scientists identify proteins associated with disease states. true
  8. Metagenomics involves the analysis of DNA collected in the environment. true
  9. The presence of a gene always implies the presence of an associated protein. false
  10. Characteristics considered desirable in an animal now may not always be regarded as desirable in the future. true