Are organic pigs environmental pigs?

From the European Institute of Food Science and Nutrition

So animal and environmentalists want the alternative pig farming: Rosy pigs are wusseln grunting and squeaking in the straw. No corrosive odor of ammonia torments the sensitive noses of bristle cattle. The environment is spared! And so alternative pig farmers promise their customers meat enjoyment with calm environmental conscience.

And indeed, from certain technically and economically complex alternative husbandry systems with bedding and the addition of fermentation aids escape compared to slatted floor conditions with manure cellar up to 30% less ammonia (1). But in other bedding systems (Tab. 2, stable type 7 & 8) higher ammonia emissions are found (3). In conventional housing systems, the conversion from full to partial slatted floors with a bed surface can reduce ammonia emissions by an additional 40% (5).

While litter materials (straw, wood chips) are stored openly after use as "dung heaps" (rotting manure) with uncontrolled nitrogen emissions (2), by covering the manure surfaces in storage containers (7, 8, 11) and by means of a modern manure - spreading method (9, 12, 15, 16) achieve high reduction rates for pollutant gas and odor emissions. The enlargement of the slurry storage area is the most important starting point, not only in order to be able to adhere to the application times that lead to low nitrogen (ammonia) losses, but at the same time in order to be able to adapt the application quantities better than before to the fertilizer requirement (14, 16).

The nutrient supply per hectare of arable land is difficult to calculate with manure spreader, since the specific weight of solid manure fluctuates considerably (12). In addition, nitrogen from manure is used much more poorly by plants (14, Tab .: 3) than nitrogen from manure. If manure is improperly spread, there is more of a risk of nitrate getting into the groundwater (14).

Ammonia (NH3) is the main pollutant gas from animal husbandry (average 8 kg NH3 / LU and year) (15) and is the cause of acid rain, forest damage, the occurrence of plant damage in the vicinity of intensive animal husbandry, extreme algae bloom, grazing of the Heide (4, 15, 16) blamed. The consequences for animals of NH3 in the stable air are reduced weight gain and effects on the respiratory tract (15).

In addition to ammonia, litter systems emit ten times more (+ 1000%) (2) of the "ozone killer" laughing gas (6, 13, 14), in contrast to slatted floors with manure basements.

These high nitrous oxide emissions, together with nitrogen oxide emissions (1) (approx. 5%), increase total nitrogen emissions into the environment through alternative litter systems (1, Tab. 2). The high emissions can be explained by the comparatively high temperature (2) in the litter and the constant rummaging through the litter by the pigs. Likewise by the size of the emitting (manure) area (2, 4, 10). In addition, most of the alternative pigs are kept in so-called open stalls, which quickly transport the harmful gases from the stalls into the environment thanks to very high air exchange rates. They are hardly noticed due to the high degree of dilution, ie it does not smell!

Ozone killer laughing gas

Laughing gas interferes with natural ozone chemistry by removing oxygen from the stratosphere, which is no longer available for ozone production. Without this reaction of the nitrous oxide there would be about 25% more ozone in the stratosphere. The most important anthropogenic sources of nitrous oxide (N2O, nitrous oxide) worldwide are the burning of fossil and biogenic fuels, the use of nitrogenous fertilizers in agriculture and is naturally produced by the bacteriological decomposition of organic matter.

Tab. 1: Comparison of ammonia and nitrous oxide emissions (13)

Barn type	Ammonia emission in kg / animal place and year	Nitrous oxide emissions in kg / animal place and year
Slatted floor	3,93	0,15
Envirozymes - Deep litter	2,70 - 3,10	1,43 - 1,89
Ecozymes - Deep litter	4,80	1,89

Tab. 2 Gaseous nitrogen emissions in various housing systems (1)

Barn type	Total N losses (ammonia and nitrous oxide) in kg per rotation and Fattening pig
1. Manure system	0,92
2. Deep litter with Envirozyme	0,95*
3. Deep litter with UMS-A-Ferm	1,23*
4. Deep litter with Ecozyme	1,33*
5. Deep litter without additive, 70 cm deep	1,45*
6. Deep litter with bio-active powder	1,55*
7. Deep litter without additive, 20 cm deep, with sprinkling	1,68*
8. Deep litter with Ecozyme, 2 x Mix per week	1,76*

* + 5% N - losses due to NO (nitrogen oxide)

Tab. 3 Manure utilizes nitrogen more poorly (14)

Nitrogen (N) - recycling of rotting manure and liquid manure if it is appropriate Application, expressed in mineral fertilizer equivalents (min. N = 100)
	Rotting dung	liquid manure
N - Short-term utilization of grain and maize	15 - 25	50 - 70
N - Short-term recovery in leaf fruits	30 - 50	80 - 100
N - long-term distortion	50 - 70	70 - 90

Conclusion

A large number of studies show that there is no satisfactory housing system in all points (economy, animal friendliness and environmental friendliness) due to negative interactions for pigs (10).

According to the current state of knowledge, an ecological superiority of (rotting) manure management compared to properly operated manure management is, in my opinion, not recognizable (14). The much-noticed nitrate discharge into the groundwater would also be lower with properly operated liquid manure management, especially in areas with high livestock numbers, than with compost manure management.

Thinking about the usefulness of a return to rotting dung does not open up any real possibilities for reducing environmental pollution. In my opinion, it should be asked whether it is not sometimes just a nostalgic dream that obscures the possibilities that really exist and slows down ongoing efforts and measures to reduce nitrate pollution.

It is important to improve nitrogen utilization, e.g. through multi-phase feeding and the use of amino acids (14, 15, 16). This is the only way to reduce the emissions that pollute water, soil and air.

Selected Literature

1. Hoy, St. et al .: "Investigations into pig farming without slurry accumulation according to the deep litter bed method - final report", University of Leipzig, September 1996
2. Krötz, W. and G. Englert: "Development of procedural measures for the reduction of NH3 emissions from solid manure with the help of a system model" 109th VDLUFA Congress, Leipzig, 15.-19. September 1997
3. Hoy, St. et al .: "Ammonia and nitrous oxide emissions: Effects of various deep litter systems for fattening pigs", Landtechnik, 52, H. 1, pp. 40-41, 1997
4. Oldenburg, J .: "Effects of ammonia emissions from pig farming and ways of reducing them", Lohmann Information, Nov. / Dec, pp. 1 - 7, 1992
5. Oldenburg, J .: "Odor and ammonia emissions from animal husbandry", Dust - cleanliness of the air, 50, pp. 189 - 194, 1990
   
6. Voermanns, JAM et al .: "Experiences and results with bedding systems from experimental stalls and farms in the Netherlands", KTBL - working paper 183, "Keeping fattening pigs in compost stalls", pp. 106-110, 1993
7. Wanka, U. et al .: "Covering materials for storage containers with pig manure in the test", Landtechnik, 53, H. 1, S. 34-35, 1998
8. Ratschow, J.- W .: "... so that the liquid manure stinks less. Possibilities of odor reduction in liquid manure systems", DGS, 46, H. 7, S. 20 - 24, 1994
9. Schürer E. and P. Reitz: "Emissions of ammonia and nitrous oxide: Influence of the application process of liquid manure", Landtechnik, 53, H. 1, pp. 36-37, 1998
10. Hesse, D. et al .: "Are animal and environmentally friendly systems possible?", DGS - Magazin, Week 23, pp. 44 - 48, 1997
11. Koch, F. and A. Winter: "Slurry storage: create storage capacities", Schweinwelt, 23, no. 3, pp. 18-21, 1998
12. Kowalewsky, H.-H .: "Solid and liquid manure technology: storage - processing - spreading" Schweinwelt, 23, H. 1, pp. 17-19, 1998
13. Hoy, St. et al .: "For the determination of the concentration and emission of gases relevant to animal and environmental hygiene in various pig husbandry systems with the help of multi-gas monitoring", Berl. Münch. Veterinarian Wschr. 109, pp. 46-50, 1996
14. Vetter, H .: "Rottemist ecologically better than liquid manure?", Landwirtschaftsblatt Weser-Ems, 140, no. 29, pp.19-22, 1993
15. Mehlhorn, G .: "Ammonia as a harmful gas for animals and the environment", Economic animal production with pig producers, 24, H. 5 S., 144-149, 1993
16. Steffens, G .: "Emissions from livestock farms and ways to reduce them", VDLUFA series of publications, No. 32, pp. 57-78, 1990

Source: Hochheim, [AHO]