| 1. |
- Berg, Lotta, et al.
(författare)
-
Killing of spent laying hens using CO2 in poultry barns
- 2014
-
Ingår i: Animal Welfare. - : Cambridge University Press (CUP). - 0962-7286 .- 2054-1538. ; 23, s. 445-457
-
Tidskriftsartikel (refereegranskat)abstract
- In Sweden, laying hens are killed using the following methods: i) traditional slaughter; ii) on-farm with CO2 in a mobile container combined with a grinder; or iii) with CO2 inside the barn. The number of hens killed using the latter method has increased. During these killings a veterinarian is required to be present and report to the Swedish Board of Agriculture. Data were registered during four commercial killings and extracted from all official veterinary reports at CO2 whole-house killings in 2008-2010. On-farm monitoring showed that temperature decreased greatly and with high variability. The time until birds became unconscious after coming into contact with the gas, based on time until loss of balance, was 3-5 min. Veterinary reports show that 1.5 million laying hens were killed, in 150 separate instances. The most common non-compliance with legislation was failure to notify the regional animal welfare authorities prior to the killings. Six out of 150 killings were defined as animal welfare failures, eg delivery of insufficient CO2 or failure to seal buildings to achieve adequate gas concentration. Eleven were either potentially or completely unacceptable from the perspective of animal welfare. We conclude that, on the whole, the CO2 whole-house gas killing of spent hens was carried out in accordance with the appropriate legislation. Death was achieved reliably. However, there remain several risks to animal welfare and increased knowledge would appear vital in order to limit mistakes related to miscalculations of house volume, improper sealing or premature ventilation turn-off.
|
|
| 2. |
|
|
| 3. |
- Löfkvist, Klara, et al.
(författare)
-
Nästa generations täckmaterial för växthus
- 2014
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I denna studie har olika nyare typer av glas som täckmaterial till växthus undersökts. Fokus har varit att hitta material som är energisparande samtidigt som de släpper igenom sa mycket ljus inom PAR (Photosynthetic active radiation) området som möjligt. De täckmaterial som valts ut har varit planglas med låg järnhalt, planglas med den mjuka lågemissionsbeläggningen optitherm, planglas med den hårda lågemissionsbeläggningen KHglas samt planglas med den självrengörande beläggningen Active. Valen har gjorts utifrån deras egenskaper vad gäller funktion, energibesparing, ljusgenomsläpplighet samt kostnaderna för materialet så att det blir ekonomiskt rimligt för dagens växthusproduktion. Täckmaterialen har placerats i taket respektive väggarna med tanke på vad som ansågs vara mest lämpligt utifrån växthusproduktion. Exempelvis har självrengörande ytor placerats i takets insida eftersom det är den yta som man i växthusproduktion befarar bli mest smutsig. För de utvalda materialen har livscykelkostnaderna (LCC) beräknats utifrån vissa givna produktionsförutsättningar för två storlekar på växthus; 1 000 m2 respektive 5 000 m2. De bästa kombinationerna av tak- respektive väggmaterial har sedan kombinerats i ett idealhus och beräkningar har gjorts. Resultaten visade att vid nybyggnation av växthus där investeringskostnaden for värmesystemet räknas med kan man i idealhuset få en livscykelkostnad som ger en besparing på 14 % jämfört med ett standardreferenshus. Investeringskostnaderna för de förbättrade glasmaterialen är då visserligen högre än för vanligt standardglas men då den beräknade energibesparingen var 30 % blir den totala kalkylen lovande.
|
|
| 4. |
- Löfkvist, Klara, et al.
(författare)
-
Pengar att spara vid nybyggnation av växthus
- 2014
-
Ingår i: Viola. - 0042-6407. ; 119, s. 24-25
-
Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Med nya växthus är det idag möjligt att förbättra det ekonomiska resultatet med nio procent om du väljer nyare glasmaterial och inte bara fortsätter med standardglas. Att välja ett energieffektivt glas innebär inte med automatik att investeringen blir dyrare. Tvärtom kan det faktiskt vara billigare att bygga växthus med ett modernt glasmaterial.
|
|
| 5. |
- Löfkvist, Klara, et al.
(författare)
-
Täckmaterial som gör att pengar kan sparas vid nybyggnation av växthus
- 2014
-
Ingår i: LTV-fakultetens faktablad.
-
Annan publikation (populärvet., debatt m.m.)abstract
- Det finns många moderna glas som har utvecklats för byggnadsindustrin. Glasen har utvecklats med fokus på energibesparingar, solskydd och optimal synupplevelse. Flera av dessa material har egenskaper som är intressanta för växthus. Med rätt kombination av nya glas i växthuset kan energibesparingar på upp emot 30% uppnås. Vid nybyggnation av växthus är det idag möjligt att i en tomatodling förbättra det ekonomiska resultatet med 400 kr/m2 under 10 år om man väljer nyare glas och inte bara fortsätter med de enklaste standardglasen.
|
|
| 6. |
- Martin Ngwabie, Ngwa, et al.
(författare)
-
Effects of animal activity and air temperature on methane and ammonia emissions from a naturally ventilated building for dairy cows
- 2011
-
Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310. ; 45, s. 6760-6768
-
Tidskriftsartikel (refereegranskat)abstract
- Knowledge of how different factors affect gas emissions from animal buildings can be useful for emission prediction purposes and for the improvement of emission abatement techniques. In this study, the effects of dairy cow activity and indoor air temperature on gas emissions were examined. The concentrations of CH(4), NH(3), CO(2) and N(2)O inside and outside a dairy cow building were measured continuously between February and May together with animal activity and air temperature. The building was naturally ventilated and had a solid concrete floor which sloped towards a central urine gutter. Manure was scraped from the floor once every hour in the daytime and once every second hour at night into a partly covered indoor pit which was emptied daily at 6 a.m. and at 5 p.m. Gas emissions were calculated from the measured gas concentrations and ventilation rates estimated by the CO(2) balance method. The animal activity and emission rates of CH(4) and NH(3) showed significant diurnal variations with two peaks which were probably related to the feeding routine. On an average day, CH(4) emissions ranged from 7 to 15 g LU(-1) h(-1) and NH(3) emissions ranged from 0.4 to 1.5 g LU(-1) h(-1) (1 LU = 500 kg animal weight). Mean emissions of CH(4) and NH(3) were 10.8 g LU(-1) h(-1) and 0.81 g LU(-1) h(-1), respectively. The NH(3) emissions were comparable to emissions from tied stall buildings and represented a 4% loss in manure nitrogen. At moderate levels, temperature seems to affect the behaviour of dairy cows and in this study where the daily indoor air temperature ranged from about 5 up to about 20 degrees C, the daily activity of the cows decreased with increasing indoor air temperature (r = -0.78). Results suggest that enteric fermentation is the main source of CH(4) emissions from systems of the type in this study, while NH(3) is mainly emitted from the manure. Daily CH(4) emissions increased significantly with the activity of the cows (r = 0.61) while daily NH(3) emissions increased significantly with the indoor air temperatures (r = 0.66). Daily CH(4) emissions were negatively correlated to the indoor air temperature (r = -0.84). This suggests that increased daily indoor air temperatures due to seasonal changes may bring about decreased animal activity which may decrease the release of CH(4) from dairy cows. Finally, changes in daily NH(3) emissions were influenced more by the indoor air temperature than by the activity of the cows. (C) 2011 Elsevier Ltd. All rights reserved.
|
|
| 7. |
- Martin Ngwabie, Ngwa, et al.
(författare)
-
EFFECTS OF ANIMAL AND CLIMATE PARAMETERS ON GAS EMISSIONS FROM A BARN FOR FATTENING PIGS
- 2011
-
Ingår i: Applied Engineering in Agriculture. - : American Society of Agricultural and Biological Engineers (ASABE). - 0883-8542 .- 1943-7838. ; 27, s. 1027-1037
-
Tidskriftsartikel (refereegranskat)abstract
- Increased knowledge of the factors that affect emissions from livestock barns may lead to a better understanding of daily (between different days) and diurnal (within a specific day) variations in emissions, an improvement of mitigation methods and a refinement of emission models. The influence of animal activity, animal weight, indoor air temperature and relative humidity on carbon dioxide, methane, and ammonia emissions was assessed on a daily and diurnal basis in a barn with three successive batches of fattening pigs. The floor was partly slatted, manure was removed daily, and the ventilation rate was fixed for each batch. Variations between the batches in mean methane emissions (0.33-1.62 g pig(-1) h(-1)) were larger than the variations in the mean emissions of carbon dioxide (84-91 g pig(-1) h(-1)) and ammonia (0.18-0.20 g pig(-1) h(-1)). Animal weight explained most of the daily variations in carbon dioxide and ammonia emissions. Animal weight and indoor air temperature explained most of the daily variations in methane emissions. A regression analysis of methane emissions as a function of the indoor air temperature and animal weight explained 56% of the variations in the measured methane emissions. Animal activity decreased with increasing animal weight and air temperature. Diurnal variations in carbon dioxide and ammonia emissions were mainly affected by the animal activity, with correlation coefficients (r) of 0.89 and 0.68, respectively. Diurnal variations in methane emissions only slightly correlated with the animal activity (r = 0.41, p = 0.05). Emission variations emphasized the need for measurements during different times within the day and during the growing period in order to obtain reliable data for assessing abatement techniques.
|
|
| 8. |
- Martin Ngwabie, Ngwa, et al.
(författare)
-
Effects of wood shavings addition and different climatic conditions on ammonia and odour emissions from fresh animal manure
- 2010
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The addition of wood shavings and changing the climatic conditions as methods of mitigating ammonia and odour emissions were investigated using fresh pig and cow manure samples. The manure from each animal type was separated into two portions and wood shavings were mixed with one portion. Emissions from identical quantities of manure with and without wood shavings were measured in a flux chamber. The manure temperature was varied between 15 and 30 ºC. Fresh air at temperatures between 15 and 25 ºC was passed at a fixed rate over the manure in the chamber. Gas and odour concentrations were measured using a photoacoustic multigas analyser 1412 (Lumasense Technologies A/S) and an olfactometer respectively. The addition of wood shavings decreased the total-N and NH4 +-N but increased the ratio between carbon and nitrogen (C/N) as well as the pH. Ammonia emissions increased with manure temperature for both manure types. Odour emissions increased with the cow manure temperature. Odour emissions had a positive tendency with the pig manure temperature for samples without wood shavings. The water vapour pressure was positively correlated to the emissions from the cow manure but not from the pig manure. A clear relationship between ammonia and odour emissions could not be established. The addition of wood shavings lowered the ammonia emissions from the cow manure but not from the pig manure
|
|
| 9. |
- Martin Ngwabie, Ngwa, et al.
(författare)
-
Influence of animal activity and weight gain on the ventilation and emission rates of greenhouse gases and ammonia from a fattening pig building in summer
- 2010
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Variations in CH4, N2O, CO2 and NH3 emissions from livestock may be caused by management routines, changes in animal activity and weight. These were investigated in a mechanically-ventilated, slurry-based pig building with a partly slated floor. The manure channels were emptied between 8–9 a.m. The ventilation rate, which was kept constant, was measured with an anemometer and calculated based on CO2 balance. The difference between both methods increased from 3% at the beginning to 35% at the end of the fattening period. Significant correlations (p < 0.001) existed between the activity and the emission rates of CO2 (r = 0.89), NH3 (r = 0.65) and N2O (r = 0.74), but not for CH4. CO2 and NH3 emissions increased at rates of 18 g CO2 pig-1 d-1 and 82 mg NH3 pig-1 d-1. CH4 emission was dumped-shaped with a maximum at pig weight of about 75 kg
|
|
| 10. |
- Martin Ngwabie, Ngwa, et al.
(författare)
-
Influence of environmental factors and the addition of wood shavings on ammonia and odour emissions from fresh livestock manure
- 2010
-
Ingår i: Agricultural Engineering International: the CIGR Ejournal. - 1682-1130. ; 12, s. 68-81
-
Tidskriftsartikel (refereegranskat)abstract
- Gaseous emissions from livestock manure may adversely affect human and animal health as well as the surrounding environment. In an effort to understand and mitigate these emissions, the effects of different environmental factors and the addition of wood shavings on ammonia and odour emissions from fresh pig and dairy cow manure were studied. The manure was divided into two portions and wood shavings were mixed with one portion. Emissions from equal volumes of both portions were measured at different environmental conditions in a flux chamber. The manure temperature was varied between 15–30 ºC. Fresh air at temperatures between 16–26 ºC was passed at a fixed rate over the manure. The addition of wood shavings decreased the total-N and NH4+-N, but increased the pH of the manure at the end of the experiment. The temperature of the manure with wood shavings increased faster than that of the manure without wood shavings. The ammonia emission from the pig manure (0.08–0.41 mg m-2 s-1) was on average much higher than the ammonia emission from the cow manure (0–0.08 mg m-2 s-1). The odour emission from the pig manure was high (21–930 OU m-2 s-1), and significantly higher than the odour emission from the cow manure (1–6 OU m-2 s-1). A positive correlation was found between the ammonia emissions and the manure temperature. Ammonia emissions were about 2 times higher at manure temperatures of about 25 ºC compared to emissions at about 15 ºC. Odour emissions were positively correlated with the temperature of cow manure. Ammonia emissions at 25 ºC were high, while odour emissions at 25 ºC were lower than those at 20 ºC for the pig manure with wood shavings. The water vapour pressure was positively correlated to the emissions from the cow manure but not from the pig manure. The measurements indicated a positive correlation between ammonia and odour emissions for the cow manure as well as for the pig manure without wood shavings. The addition of wood shavings to animal manure does not seem to automatically mitigate ammonia or odour emissions as it also affects the temperature and the pH
|
|
