The present data refer to production
processes on six typical Danish pig farms, which combines livestock and
(cash) crop production in a mixed farming system. The pig production can
be either sow-keeping alone (selling piglets for fattening), only fattening
of pigs (25-90 kg) or both. Nitrogen
balances for different pig farms can be seen here.
The main characteristics of the six
farms are summarized in Table 1.
Table 1: Main characteristics of
the considered pig farms.
A large part (ca. 50%) of
the feed for the pig is produced on the farm mainly as cereals, because
overall legislation sets minimum requirements for land available for manure
application for each separate livestock farm. Moreover, some of the farms
with lower stocking rate produce grains, rapeseed or grain legumes as
cash crops. Most sows are of high genetic potential and 57% of sows are
inseminated artificially (AI). Most farms have stables with slatted floors
(manure handled as slurry). 3.3 % of the sows live in outdoor production
systems with small mobile huts in grass paddocks. All used water and effluents
from stables are collected in concrete slurry containers with a minimum
capacity corresponding to 7-9 months slurry production (application to
fields is only allowed from March to September). Cultivation of crops
is often done using farmers own equipment while harvest of grains is most
often done by contractors. Increasingly, however, contractors carry out
all field operations on large pig farms. Equipment is usually modern and
most processes are highly automatic.
There is most often one owner and
1-4 full time hired helpers, most of who have diploma in farm management.
Most farmers use modern feed planning methods and regular feed analyses
to adjust protein levels and minerals and all follow public regulation
concerning manure nitrogen utilization and fertilization.
Data collection and treatment
All Danish farms are obliged to keep
detailed records of purchases and sales for tax purposes and the yearly
accounts are made with professional help. A representative set of these
accounts, 2239, are reported by the advisors to the Danish Research Institute
of Food Economics (FØI)
and constitute the basic empirical input to the farm types presented here.
Besides the economical data, information on the land use, livestock numbers
and amounts produced are included in the data set by the advisors.
Data from other sources are used
to model the technical processes: Data from the advisory services (feeding
practices), the Directorate for Food, Fisheries and Agri-business and
Statistic Denmark (countrywide use of fertilizer and concentrates, partition
of land use on different crops and their total yields). The Danish Institute
of Agricultural Sciences (DIAS) together with FØI and Statistic Denmark
is responsible for data collection.
The data processing and details of
the different farm types is the responsibility of DIAS and FØI. The FØI
checks the account data and has divided the accounts according to the
farm typology presented. These average data
from each farm type has been used by DIAS to model a typical farm in terms
of land use, herd size and production. The inputs and outputs (products
and emissions) from the production processes are quantified using the
farm level as the basic unit and all the single enterprises have been
described so that they fit coherently into the overall farm balances (e.g.
crop production must fit the sum of homegrown feed used and exported).
Thus, inputs of fertilizer, feeds and minerals are calculated to mach
the livestock and cash crop production after correction for home grown
feed (see also under validation).
The nutrient turnover on the farm
is calculated by multiplying the physical turnover of inputs and products
with N and P contents following standard procedures. Emissions of ammonia,
methane and nitrous oxide (N20) from the livestock, stables,
manure storage and handling and from crop residues and soil are calculated
using standard coefficients (IPCC, 2000)) on the amounts of nutrients
and feed dry matter (DM).
Direct Energy use is determined by
the use of a model that attaches diesel use to field operations following
Dalgaard et al. (2000).
The inventory includes all processes
on the farm necessary for the cultivation and preservation of crops and
home-produced fodder (e.g. soil preparation, sowing, fertilizing/manuring,
plant protection, harvesting and transport of crops).
Feeding and tending sows, young stock
and pigs and handling of bi-products such as manure and straw, use of
electricity for ventilation and light is also included.
Resource use and emissions related
to the production of fertilizer, imported feeds, minerals and electricity
are handled as external processes. This means that they should be included
in the calculation of emissions per kg of meat at a later stage.
Use of medicine is not considered. Resource use and emissions
related to the construction and maintenance of buildings is not included.
Depreciation of machinery is included with rough standard estimates based
on the use of steel for tractors and tools.
Most pig farm types produce small
amounts of other product than piglets and meat, e.g. bread wheat. All
inputs, resource uses and emissions related to these secondary enterprises
have been included in the inventory. Only technical allocations have been
made between enterprises within the farm and only when resources used
could be clearly divided between the enterprises. Systems expansion has
been used to account for these secondary products and for the exported
manure from farm types with high stocking rate. Thus, the difference in
fertilizer use and emissions on the manure receiving farm type (modeled
as before and after manure import) has been allocated to the manure farm
of 2239 accounts used is statistically representative of the Danish farming
sector (59000 farms in total) following a method developed over several
decades for yearly economical analysis of Danish farms (farm typology
presented) and for
reporting to other bodies like the EU Farm Accountancy Data Network.
The data represent only one year
(1999), but the large number of farms allows for some generalizations
of the input-output relationships.
The established typology is based
on the main enterprise and a given farm could be included in only one
The present pig farm types are based
on 6 sub samples. Together they represent all Danish pig farms with a
minimum of 10% of farm Gross Margin from pig production (a small group
of organic pig producers are not represented). The total pig production
on these types account for 78% of the total pig meat produced in Denmark.
The farms have been divided into groups in order to represent pig production
on sandy and loamy soil types respectively and with different stocking
rates (number of standard livestock units per hectare). All types have
a sufficient number of farms to ensure a high degree of representativity,
with the smallest samples found in types with high stocking . Farms with low or medium stocking rates usually produce
1-3 secondary products, which may differ from farm to farm. The resulting
farm type thus represents an average of these secondary enterprises, but
the number of small enterprises is not typical for a single farm.
Included pig farm types:
There are important differences between
the pig farm types. The farms on clay soils tend to feed more imported
feeds and crop residues because cash crop production is relatively more
competitive than on sandy soils. The farms with high stocking rate sell
part of their manure production.
The representativity of the farm
accounts has been checked using standard methodology at FØI. The resource
use and production on the farms have been validated at two levels: Internal
coherence within each farm type and overall coherence between the sum
of farm types and national level input use and production.
On the farm level the quantification
of each type has been validated primarily by checking the coherence between
land use, crop yields and livestock production (e.g. the feed needed for
the herd matches the home-produced feed plus imported feeds less sold
cash crops and the sum of homegrown feeds and sold crops fits the land
At a higher hierarchical level the
land use has been validated by comparing the sum of each crop acreage
over all types with national statistics for the same year, e.g. checking
that the total wheat area and total wheat yield does not differ more than
a few % from the national statistics.
Likewise, the total estimated use
of inputs like diesel, fertilizer and concentrated feeds across all farm
types have been checked against statistical information on national level.
In case of differences that could not be ascribed to an error in a specific
type, a general correction factor was multiplied into all types for the
relevant input item. For more details, see Data
Inputs and outputs
Inputs and outputs associated with production processes at the six different types of pig farms are shown in table 3. Data are provided per farm per year. The farm type, “Sandy with livestock density < 1,4 LU per ha” is considered the marginal farm; that is, the farm type most likely to expand production in the future.
Data entry: data have been entered
into Simapro by Randi Dalgaard, DIAS and transformed into this format
by Per H. Nielsen, 2.-0 LCA Consultants
Anonymous, 1999:Ammoniakfordampning – redegørelse nr. 1. Emission af ammoniak fra landbruget – status og kilde. (Ammonia emission from Danish Agriculture.
IPCC, 2000. Intergovernmental Panel on Climate Change. Good Practice or Guidance and Uncertainty Management in Greenhouse Gas Inventories.www.ipcc-nggip.iges.or.jp
Dalgaard, T., Halberg, N. og Fenger, J., 2000. Simulering af fossilt energiforbrug og emissioner af drivhusgasser. Tre scenarier for omlægning til 100% økologisk jordbrug i Danmark.