### Animal husbandry

#### Indicators:

Number of animals (extensive and intensive) Number of slaughtered animals (extensive and intensive) | Feed efficiency of animals (extensive and intensive) Feed per animal (extensive and intensive) Feed for animals (extensive and intensive)

This view shows how animal production systems are modelled and how animal productivity influences land use by claiming land for feed production and grazing.

The data and scenarios shown are the number of animals (total population), number of slaughtered animals, feed efficiency (conversion of intake to animal products), feed requirement per animal and total feed requirement for all animals. Future scenarios are based on specific assumptions.

The plant production systems (i.e. food and feed crops, biofuel crops and grass, and fodder species) as well as land requirements are described under land use. The underlying demand for animal products can be viewed under agricultural demand and agricultural trade.

| #### Number of animals
| unit: million head dimension: region, animal category

The number of animals specifies the animal population of the different animal categories, including non-dairy cattle, dairy cattle, pigs, sheep and goats (as one group), and poultry. The number of animals is derived from the required production of animal products and the animal productivity.

The productivity for cattle, sheep, goats and pigs depends on the off-take rates (i.e. the fraction of the population that is slaughtered each year) and the production per animal (i.e. carcass weight). For dairy cattle the productivity is determined by the milk production per head per year. For poultry the production of meat and eggs per head per year is used.

Animals require feed in the form of food crops, crop residues, grass and fodder species, and animal products (in particular milk). This has a major impact on land use. Croplands, in particular, used to yield crops for feed, and grasslands are important in this respect. Residues and animal products used for animal feed are assumed to be by-products and do not require additional land.

| #### Number of slaughtered animals
| unit: million head dimension: region, animal category

Given the production of animal products, the number of slaughtered animals is determined by the off-take rate (i.e. the fraction of the animal population slaughtered each year) and the carcass weight for the animal considered.

For some animal categories (for example, pigs and poultry) the off-take rate may exceed 100%, indicating that the number of animals slaughtered each year exceeds the stock of animals. This means that these animals have a production cycle of less than one year.

In future scenarios the off-take rates and carcass weights have a certain target value; this is reached in a target year according to specific generic rules, as outlined in scenario assumptions for land use (see scenario context).

| #### Feed efficiency of animals
| unit:kg DM/kg prod. (kg feed as dry matter per kg of product) dimension: region, animal category

Feed efficiency is defined as the total amount of feed in kg dry matter (DM) required for the production of 1 kg of mutton, goat meat, poultry, eggs, pork, beef or cow's milk. The feed is composed of various types, which are not specified here because the energy content per kg dry matter is assumed to be about the same for all feed types (i.e. crops, crop residues, animal products and grass).

The calculation of feed efficiency in dairy and non-dairy cattle (i.e.cow's milk and beef) production distinguishes six components according to energy requirements: maintenance, collection of feed, growth, lactation, animal traction and calving. In future scenarios the feed needed for the production of 1 kg of beef or cow's milk decreases although the amount of feed per animal increases due to the rapid increase in the production per animal.

The feed efficiency for sheep and goats in the 1970-1995 period are based on the overall technological level of the region. For pig and poultry production systems estimates are based on various literature sources. After 1995, feed efficiencies for sheep and goats, pigs, and poultry change, approaching a target value in a certain target year according to specific generic rules.

| #### Feed per animal
| unit:kg DM/Head/day (kg feed in dry matter per head per day) dimension: region, animal category

The feed required per animal per day is the calculated as product of animal productivity and feed efficiency.

In most scenarios, the required amount of feed per animal increases because animal productivity growth often exceeds feed efficiency increase. In other words, the feed requirement per animal increases while the feed per unit of product decreases. The amount of feed per animal remains constant when the animal productivity and feed efficiency have reached their ceilings.

| #### Feed for animals
| unit:1000 Gg/yr (million ton of feed dry matter per year) dimension: region,animal category, feed type

This variable represents the total amount of feed required for the production of animal products. Grass and fodder species are consumed by grazing animals only (dairy and non-dairy cattle, sheep and goats) while food crops are mainly fed to pigs, poultry and also cattle.

The production of grass and fodder species, and food crops used as feed, require large areas of land. Comparison of the crops used as animal feed with the total production of food crops clearly shows the relative importance of animal production for the total crop area. Crop residues and animal products (mainly milk) do not require extra land.

In future scenarios the use of grass and crops and crop residues as animal feed changes to approach a target value in a scenario-specific target year according to specific generic rules.