About » CONDITIONS DEFINING THE ENVIRONMENTAL IMPACT OF INDUSTRIAL LIVESTOCK FARMING

Negative environmental impactoflarge-scale livestock farming depends on the livestock type and size,thefarming technology, and the handling and use of animalfertilisers. In consideration of the livestocksize and the consumptionvolume of products of animal origin in the Baltic Searegion, pig,poultry and cattle farming appears to have the heaviestenvironmentalimpact.

In terms offarmingtechnology, large-scale intensive livestock production causes thehighestenvironmental burden.With reference tothe animal rearing system,and the type of fertilisers produced (naturalfertiliser according tolegal terms or organic fertiliser in agronomic terms),livestock farmscan be divided into litter or non-litter systems (straw-beddedornon-straw-bedded).

The mostdisadvantageous, fromenvironmental point of view, is non-litter rearingsystem, which generates highvolumes of slurry. Slurry is a naturalliquid mixture of excreta, urine andwater (used to rinse animal wastefrom the livestock buildings and for hygiene;it accounts for 10-20% ofthe total slurry volume) and feed residues. Dependingon the content ofdry matter, slurry can be divided into dense slurry (amixture of excretaand urine in natural proportions, without or with smallamount of water;dry mass >8% - for cattle and pig slurry, and >20% forpoultryslurry), and liquid/diluted slurry (a mixture of excreta and urinewithhigher water content; dry mass <8%).

Thevolume and composition ofslurry depend on the species, age andcondition of animals, livestock population, purpose of livestockproduction, fattening intensity, type of feed, zoohygienic conditions,and the volume of water used. The percentage proportionof excreta to theanimal body mass is as follows: dairy cattle (up to 500 kg) - 4.6%forexcreta and 3.3% for urine, fattening pigs (around 90 kg) - 2,0% forexcretaand 3.0% for urine, laying hens - 10%. The chemical compositionof dense cattleslurry is as follows: C - 3.00%, N - 0.45%, P2O5 - 0.20%,K2O - 0.60%, CaO - 0.30%, Na2O - 0.09%, MgO - 0.10%, Cl - 0.09%, S -0.04%, B - 3.50 ppm (10-4%), Cu - 3.70 ppm, Mn - 18.70 ppm, Mo - 0.30ppm, Co - 0.15 ppm, Zn - 20.00 ppm. The chemical composition ofdense pigslurry is as follows: C - 3.5%, N - 0.64%, P2O5 - 0.40%, K2O - 0.48%,CaO - 0.30%, Na2O - 0.09%, MgO -0.10%, S - 0.07%, B - 3.00 ppm, Cu -10.40 ppm, Mn - 21.40 ppm, Mo - 0.17 ppm, Co - 0.09 ppm, Zn - 39.70 ppm.The chemical composition of dense poultry slurryis as follows: C -7.00%, N - 1.30%, P2O5 - 1.10%, K2O - 0.60%, CaO - 1.40%, Na2O - 0.15%,MgO - 0.17%, S - 0.15%, B - 5.00 ppm, Cu - 14.00 ppm, Mn - 46.00 ppm, Mo- 0.45 ppm, Zn - 67.00 ppm (volume and composition of slurry producedby farmed animal species are listed in Annex VIII and Annex IX).

Slurryand fermented urine(which is described later) are a rich source ofnitrogen which is easilyabsorbed by plants. It is estimated that around50% and 20% of nitrogencontained in slurry and manure, respectively, issoluble in water.<spanstyle='mso-spacerun:yes'>Both slurry andfermented urine arefast-acting fertilisers similar to mineral ones, andare therefore less safe forthe environment (high risk ofover-fertilisation).

Slurry fermentsand producesgases (up to 300 L/kg of organic matter in dense slurry).Toxic anaerobic fermentation (decomposition)products, including ammonia,hydrogen sulphide, carbonyl compounds, amines, andthiols, areparticularly environmentally burdensome. Absence of biothermaldryingprocess (hygienisation) is another disadvantage of slurry. Slurryhas low temperature,i.e.8-12 °C in the winter period andround 15-17 °Cin the summer, at which pathogens and parasites are able tosurvive.

Slurryis a highlyconcentrated fertiliser rich in minerals andmicrobiologically contaminated.Unless it is stored, landspread ordisposed correctly, it can pose a seriousthreat to the naturalenvironment and human health.

Livestockproductionintensification and industrialisation makes the use ofnon-litter systems moreand more common. As a result, liquid animal wastecan be more easily (ascompared to manure) mechanically collected anddisposed from animalhousings.However, slurry utilisation ismoreproblematic. In the majority of cases, present-day large-scalelivestockfarms do not have sufficient area of land for landspreading.Slurry on-farmtreatment is an alternative. However, it can be a serioustechnical challenge(mechanical, chemical and biological treatmentmethods are necessary, largevolumes of slurry need to be transported,and a dedicated on-farm slurrytreatment plant need to be built) and afinancial investment (this is the mostexpensive slurry utilizationmethod), whereas the treatment effectivenesscontinues to be low(purified slurry is rich in biogenic substances andmicroorganisms, up to23,000/1 mL).

There can be a shallowbeddingsystem (where waste is regularly removed and stacked in heaps ordisposed intoa reception pit with a below-ground tanker) or a deeplitter system (the animalwaste accumulating in livestock buildings istypically removed twice a year).In the first case, manure and fermentedurine are produced, in the second case - manure only.

Fermentedurine contains someexcreta and water and is used for hygienic purposes(cleaning stalls, udders,etc.); it is drained from the bedding (litter)and contains 1-3% of dry mass).The volume of fermented urine depends onthe volume of urine produced byanimals and soaked into the bedding. Itis estimated that 1 LU (livestock unit)(Annex V) of cattle producesaround 10 L of fermented urine, and 1 LU of swine? 15 L. Around 50-90%of urine (on average) is drained from the bedding viasewage drains inthe livestock housing to a covered and leak-proof fermentedurine store.

Thecomposition of fermentedurine differs from that of slurry and manuremainly due to the fact that, ifstored properly and non-diluted withwater, fermented urine should contain thesame composition andproportions of minerals as non-fermented urine. Urine offarm animalscontains as much as 80% of potassium and 45% of nitrogen (the restisexcreted with faeces), which makes fermented urine a typicalnitrogen-potassiumfertiliser. The composition of minerals in fermentedurine of cattle (kg/m3)is as follows: N ? 3.20, P2O5 ? 0.30, K2O ?8.00,CaO ? 0.60, MgO ? 0.40, B ? 2.40, Cu ? 0.34, Mn ? 2.74, Mo ? 0.06, Zn?1.91, Co ? 0.04, Fe ? 28.05. Fermented urine of swine contains: N ?2.80, P2O5? 0.40, K2O ? 4.10, CaO ? 0.80, MgO ? 0.30, B ? 1.48, Cu ?0.60, Mn? 3.87, Mo ? 0.14, Zn ? 3.82, Co ? 0,07, Fe ? 73.26.

Incorrectdisposal and storageof fermented urine results in large losses ofgaseous nitrogen (ammonia).Fermented urine must be diluted with waterbefore it can be landspread (at1:1-1:4 proportions), and its use forland fertilisation involves higher waterconsumption.

Manure,a composition ofexcreta, urine and litter, contains much more solidorganic matter (around20-30% dry mass) and its temperature of up to60-75 °C is much higher than thatof slurry (conditions for pathogens andparasites growth are much lessfavourable) and as such, it is consideredmuch more friendly for the naturaland agricultural environment.

Manurecomposition dependsmainly on the animal species, age and rearingconditions, as well as type offeed, volume and quality of litter, aswell as the manure storage method andperiod. Manure contains 0.50% ofnitrogen, 0.30% of phosphorus (P2O5),and 0.70% of potassium (K2O). 60%of organic matter contained inmanure is the so-called active humus,which makes manure, if used properly, ahighly effective organicfertiliser which is safe for water and soil.

Inshallow bedding systems, manureis collected outside livestockbuildings, in manure slabs which have aleak-proof slightly inclinedfloor so that precipitation water can wash themanure (manure water) downto the proper storage tank (Annex XIII).

Fromthe environmentalprotection point of view, biothermal purification isthe most favourablecharacteristics of manure as it eliminates allmicroorganisms contained in it.Biothermal purification is most effectivein manure with the humidity levels of70%, which is properly layered andstored. Biothermal processes release someammonia, methane, carbondioxide and hydrogen sulphide; however, theenvironmental burden and airpollution are much lower than emission levels fromslurry, fermentedurine, or manure produced in a deep litter system.

Deeplitter system producesmuch more manure, mainly due to low organicmatter losses (including nitrogenand phosphorus), higher litter contentand full urine absorption. Theaccumulated manure is compacted byanimals. Deep litter releases large volumesof ammonia, hydrogen sulphideand carbon dioxide, which significantlydeteriorate the sanitaryconditions of livestock housing. If manure is storedincorrectly,nitrogen losses can be as high as 40%.

Poultrylitter is a specialtype of natural fertiliser as it has a differentcomposition. Poultry littercontains high share of dry mass and organicmatter and highly concentratedminerals ? around 25.6 g of nitrogen/kg,8.3g of phosphorus/kg, and 17.0g ofpotassium/kg. Poultry manure has thehighest NPK content. Bird droppingsinclude liquid urine and solid urineacid; due to unbalanced diet, largeamounts of undigested organiccompounds (mainly phosphorus) are excreted.

Manureproduced at fur farmsis environmentally burdensome as well. Dailyvolumes of excreta produced bydifferent fur animal are as follows: adultfox - 0.25 kg of excreta and around 0.25 L ofurine, mink ? around 0.12kg of excreta and around 0.05 L of urine, coypu ?around 0.10 kg ofexcreta and 0.30 L of urine,rabbits ? from around 0.14 (small) to around0.33 (large) kg of excreta,chinchilla ? around 0.02 kg of excreta andaround 0.08 L of urine. Mineral levelsin fertilisers produced by furanimals are relatively high ? mink manure ?around 13.7 g of nitrogen,around 35.5 g of phosphorus and around 2.47 g of potassium,coypu manure(non-diluted) ? around 7.9 g of nitrogen, around 6.6 g ofphosphorus andaround 3.2 g of potassium. According to the Act of 10 July 2007onfertilisers and fertilisation (Polish Journal of Laws Dz.U.2007.147.1033),residues of fur animals are not classified asfertilisers. Manure produced byfur animals (which are predominantlycarnivorous) have to be composted for atleast one year because of thepresence of parasites (Echinococcus granulosus eggs, etc.). Inaddition, excreta, urine and feed ofanimals kept in cages fall down ontothe ground, which increases the risk thatbiological impurities andbiogenic substances are leached to the soil. Becauseof high watercontent (bathing water, process water, feed, litter), it isalsochallenging to make use the manure produced by coypu (nutria) keptin cageswith access to water ponds.

Althougharound 95% of farmanimals in Poland are kept in litter systems, manureproduction declines due toprogressive livestock productionindustrialization. It takes much work and time to remove andhandlemanure, and the manure handling process is difficult to automate.Forexample, if produced and handled in a traditional manner, manurehandling cantake 10-12% of total farm work load.

 

Federacja Zielonych GAJA
5 Lipca 45, 70-374 Szczecin, Poland
Phone. +48 91 489 42 33
Fax + 48 91 489 42 32
fzbiuro@gajanet.pl


Coalition Clean Baltic
Östra Ågatan 53
SE-753 22 Uppsala, Sweden
SHORT ABOUT THE PROJECT

Project Industrial animal farms in the Baltic Sea Region - sustainable practices to reduce nutrient loads is a part of a long-term campaign of the Coalition Clean Baltic and Green Federation "GAJA", aiming to reduce the negative impact of large-scale animal production on the environment and local communities in the Baltic Sea Region, particularly by reducing nutrient run-off into the sea. The project is part-financed by the European Union. This website reflects only the view of the Coalition Clean Baltic. The Executive Agency for Small and Medium-sized Enterprises (EASME) is not responsible for any use that may be made of the information it contains.