Poultry farm Production

Process description

The present data refer to production proces on typical Danish poultry farms. The farms are specialised in either egg or chicken (broiler) production and these poultry enterprises are considered separately from crop production. All feed is purchased as composite mixtures to be supplemented with wheat and they have soy meal as the main protein source. Most manure is exported to crop farms, because the poultry farms have little land.

The production is organised in large closed houses with artificial ventilation and usually automatic feeding. Broilers are produced as "all-in-all-out" with 50-100,000 chicken in one batch taking 40 days and using in average 3.5 kg feed to reach slaughterweight of app. 2 kg. After clearing of manure the cleaned house is left empty for two weeks before the next batch is inserted. The young chicks are produced in specialized companies using modern incubators.

Laying hens are kept either in cage systems (around 50% of egg-production) or in free range systems mostly in large houses with small amounts of loose material on the floor (straw, sawdust etc.) Only few conventional hens have access to outdoor runs. The model used apply to indoor systems. A separate model for organic hens will consider the systems with outdoor runs.

All used water and effluents from stables are collected either 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) or as manure/deep litter straw bedding to be stored/composted. 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

Data collection:

The Danish Institute of Agricultural Sciences (DIAS) together with FØI and Statistic Denmark is responsible for data collection. Data from Dansk Fjerkræråd (Danish Poultry Board) on feeding practices, the Directorate for Food, Fisheries and Agri-business,Danish Plant Directorate (nutrient content in feeds) and Statistic Denmark (countrywide use of fertilizer and concentrates) have been used to model the technical processes.

Two farm types with respectively laying hens and broiler production were established as part of the overall typology for Danish farms used for this LCA database (see under typology). These types were neccessary in order to account for the total crop production, land use, feed and fertiliser use etc. at national level. However, contrary to the other enterprises based on the set of representative account the poultry production was not well represented by the typology, probably because a major part of the Danish production takes place on landless enterprises not included in the farm accounts data set. Therefore, the poultry production is modelled separately from the land use.

Simple models of production of chicken and eggs were build on the basis of recordings of feed use and productivity in the efficiency control covering 21% of the eggproduction and app. 50% of broilers (Poulsen et al, 2001; Dansk Fjerkræråd, 2000).

Data treatment:

The data processing and details of the different enterprises is the responsibility of DIAS.

The nutrient turnover in the entreprise is calculated by multiplying the physical turnover of inputs and products according to the models described above with N and P contents following standard procedures. Emissions of ammonia, methane and nitrous oxide (N₂0) from the livestock, stables, manure storage and handling are calculated using standard coefficients (IPCC, 2000)) on the amounts of nutrients and feed dry matter (DM). All manure is exported but only the N an P fractions replacing fertiliser are deducted from the enterprise N and P balances. Emissions from soils are included and were assumed to correspond to the farm types recieving manure (see cash crop farm).

Direct Energy use is determined by the use of a model that attaches diesel use to manure handling operations following Dalgaard et al. (2000). Standard values from experts in farm buildings were used for energy use in stables.

Technical scope 

The inventory includes processes related to poultry production only.

Feeding and tending hens and/or chicken and handling of by-products such as manure, use of electricity for ventilation and light is also included.

Resource use and emissions related to the production of all feeds, minerals and electricity are handled as external processes. This means that they should be included in the calculation of emissions per kg of egg or 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.

Representativity

The dataset 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.

However, theses accounts did not represent well the total poultry production probably because an important part of the landless company-owned production units were not included in the data set. The data from the efficiency control by the Dansk Fjerkræråd (Danish Poultry Board) used for modelling the production of eggs and broilers represent 21 and app. 50% respectively of the total production in Denmark 1999. The exact data for broilers correspond to a medium-high efficiency (40 days to reach 1.95 kg) in 1999. The values for egg production is an average of cage and floor (indoor) systems (not one of them may be considered the single marginal type). The use of soybean meal for feeding was finally adjusted according to the national level correction as described under validation.

Validation

The models of poultry enterprises have been checked by advisors in Danish FjerkræRåd. The overall coherence between the sum of all farm types (see under typology) and nation level input use and production has been checked as described for pig farms.

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.

The total number of eggs and chicken produced and the use of soybean meal was checked against national statistics.

Inputs and outputs

Inputs and outputs associated with production processes at the two types of poultry enterprises are shown in table 3.

 
Administrative information

Data URL: http://www.lcafood.dk/processes/agriculture/poultryfarms.html
Version no.: 0.01
Authors: Niels Halberg, Danish Institute of Agricultural Science and Per H. Nielsen, 2.-0 LCA Consultants.
Data responsible: Randi Dalgaard and Niels Halberg, DIAS

Contact: Niels Halberg

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
Data Completed: July, 2003.

References

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.

Det danske Fjerkræråd, 2000: Effektivitetskontrol. Beretning 2000.

Damgaard Poulsen, H., Børsting, etc. 2001: Kvælstof, fosfor og kalium i husdyrgødning - normtal 2000. DJF-Rapport nr. 36, pp 59-71.