{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T04:28:20Z","timestamp":1775017700713,"version":"3.50.1"},"reference-count":50,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2022,4,11]],"date-time":"2022-04-11T00:00:00Z","timestamp":1649635200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Conseller\u00eda de Educaci\u00f3n, Universidade e Formaci\u00f3n Profesional and Conseller\u00eda de Econom\u00eda, Emprego e Industria from the Galician Government (Xunta de Galicia)","award":["ED431B 2018\/12\u2010GPC"],"award-info":[{"award-number":["ED431B 2018\/12\u2010GPC"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>This paper aims to study the evolution of CO2 concentrations and emissions on a conventional farm with weaned piglets between 6.9 and 17.0 kg live weight based on setpoint temperature, outdoor temperature, and ventilation flow. The experimental trial was conducted during one transition cycle. Generally, the ventilation flow increased with the reduction in setpoint temperature throughout the cycle, which caused a reduction in CO2 concentration and an increase in emissions. The mean CO2 concentration was 3.12 g m\u20133. Emissions of CO2 had a mean value of 2.21 mg s\u22121 per animal, which is equivalent to 0.195 mg s\u22121 kg\u22121. A potential function was used to describe the interaction between 10 min values of ventilation flow and CO2 concentrations, whereas a linear function was used to describe the interaction between 10 min values of ventilation flow and CO2 emissions, with r values of 0.82 and 0.85, respectively. Using such equations allowed for simple and direct quantification of emissions. Furthermore, two prediction models for CO2 emissions were developed using two neural networks (for 10 min and 60 min predictions), which reached r values of 0.63 and 0.56. These results are limited mainly by the size of the training period, as well as by the differences between the behavior of the series in the training stage and the testing stage.<\/jats:p>","DOI":"10.3390\/s22082910","type":"journal-article","created":{"date-parts":[[2022,4,10]],"date-time":"2022-04-10T23:06:01Z","timestamp":1649631961000},"page":"2910","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Evolution and Neural Network Prediction of CO2 Emissions in Weaned Piglet Farms"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1516-7869","authenticated-orcid":false,"given":"Manuel R.","family":"Rodriguez","sequence":"first","affiliation":[{"name":"Department of Agroforestry Engineering, Higher Polytechnic Engineering School, University of Santiago de Compostela, 27002 Lugo, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Roberto","family":"Besteiro","sequence":"additional","affiliation":[{"name":"Centro de Investigaciones Agrarias de Mabegondo, Xunta de Galicia, 15318 A Coru\u00f1a, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Juan A.","family":"Ortega","sequence":"additional","affiliation":[{"name":"Conseller\u00eda do Medio Rural, Xunta de Galicia, 36500 Lalin, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4586-7620","authenticated-orcid":false,"given":"Maria D.","family":"Fernandez","sequence":"additional","affiliation":[{"name":"Department of Agroforestry Engineering, Higher Polytechnic Engineering School, University of Santiago de Compostela, 27002 Lugo, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9606-8282","authenticated-orcid":false,"given":"Tamara","family":"Arango","sequence":"additional","affiliation":[{"name":"Department of Agroforestry Engineering, Higher Polytechnic Engineering School, University of Santiago de Compostela, 27002 Lugo, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,4,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"319","DOI":"10.1016\/S2095-3119(20)63425-6","article-title":"Driving factors of direct greenhouse gas emissions from China\u2019s pig industry from 1976 to 2016","volume":"20","author":"Dai","year":"2021","journal-title":"J. Integr. Agric."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"272","DOI":"10.1002\/2017GH000103","article-title":"Impacts of intensive livestock production on human health in densely populated regions","volume":"1","author":"Smit","year":"2017","journal-title":"GeoHealth"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"86","DOI":"10.1016\/j.agee.2008.11.016","article-title":"Gaseous emissions from weaned pigs raised on different floor systems","volume":"130","author":"Cabaraux","year":"2009","journal-title":"Agric. Ecosyst. Environ."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1016\/j.agee.2012.01.006","article-title":"Ammonia and greenhouse gas emissions during the fattening of pigs keton two types of straw floor","volume":"150","author":"Philippe","year":"2012","journal-title":"Agric. Ecosyst. Environ."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1016\/j.agee.2014.08.015","article-title":"Review on greenhouse gas emissions from pig houses: Production of carbon dioxide, methane and nitrous oxide by animals and manure","volume":"199","author":"Philippe","year":"2015","journal-title":"Agric. Ecosyst. Environ."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1016\/j.biosystemseng.2014.07.011","article-title":"Carbon dioxide production from a fattening pig building with partial pit ventilation system","volume":"126","author":"Zong","year":"2014","journal-title":"Biosyst. Eng."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2001","DOI":"10.2134\/jeq2007.0386","article-title":"Methane and carbon dioxide emission from two pig finishing barns","volume":"37","author":"Ni","year":"2008","journal-title":"J. Environ. Qual."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"483","DOI":"10.1016\/j.biosystemseng.2005.09.002","article-title":"Ventilation flow in pig houses measured and calculated by carbon dioxide, moisture and heat balance equations","volume":"92","author":"Blanes","year":"2005","journal-title":"Biosyst. Eng."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"49","DOI":"10.4995\/wrs.2011.802","article-title":"Characterization of the indoor environment and gas emissions in rabbit farms","volume":"19","author":"Calvet","year":"2011","journal-title":"World Rabbit. Sci."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2449","DOI":"10.3382\/ps.2011-01580","article-title":"The influence of broiler activity, growth rate, and litter on carbon dioxide balances for the determination of ventilation flow rates in broiler production","volume":"90","author":"Calvet","year":"2011","journal-title":"Poult. Sci."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1006\/bioe.2001.0025","article-title":"Diurnal variation in ammonia, carbon dioxide and water vapour emission from an uninsulated, deep litter building for growing\/finishing pigs","volume":"81","author":"Jeppsson","year":"2002","journal-title":"Biosyst. Eng."},{"key":"ref_12","first-page":"19","article-title":"Carbon dioxide production in animal houses: A literature review","volume":"5","author":"Pedersen","year":"2008","journal-title":"Agric. Eng. Int. CGIR E J."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1016","DOI":"10.5424\/sjar\/2013114-3185","article-title":"Effect of different dietary strategies on gas emissions and growth performance in post-weaned piglets","volume":"11","author":"Montalvo","year":"2013","journal-title":"Span. J. Agric. Res."},{"key":"ref_14","unstructured":"Pepple, L.M., Burns, R.T., Xin, H., Li, H., and Patience, J. (2011). Ammonia, hydrogen sulfide, and greenhouse gas emissions from wean-to-finish swine barns fed diets with or without DDGS. Proceedings of the Agricultural and Biosystems Engineering Conference Proceedings and Presentations, Louisville, Kentucky, 7\u201310 August 2011, American Society of Agricultural and Biosystems Engineering."},{"key":"ref_15","first-page":"89","article-title":"Emission of harmful gases from poultry farms and possibilities of their reduction","volume":"34","author":"Broucek","year":"2015","journal-title":"Ekologia"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"620","DOI":"10.1016\/j.atmosenv.2014.09.037","article-title":"Ammonia and greenhouse gas emissions from a modern US swine breeding-gestation-farrowing system","volume":"98","author":"Stinn","year":"2014","journal-title":"Atmos. Environ."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Guingand, N., Quiniou, N., and Courboulay, V. (2010). Comparison of ammonia and greenhouse gas emissions from fattening pigs kept either on partially slatted floor in cold conditions or on fully slatted floor in thermoneutral conditions. International Symposium on Air Quality and Manure Management for Agriculture Conference Proceedings, Dallas, TX, USA, 13\u201316 September 2010, American Society of Agricultural and Biological Engineers.","DOI":"10.13031\/2013.32688"},{"key":"ref_18","first-page":"168","article-title":"Emissions of greenhouse gases and ammonia from intensive pig breeding","volume":"53","author":"Mihina","year":"2009","journal-title":"Folia Vet."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1548","DOI":"10.1016\/j.atmosenv.2008.11.009","article-title":"Definition of yearly emission factor of dust and greenhouse gases through continuous measurements in swine husbandry","volume":"43","author":"Costa","year":"2009","journal-title":"Atmos. Environ."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2391","DOI":"10.1016\/j.atmosenv.2006.11.005","article-title":"Greenhouse gas emissions from swine barns of various production stages in suburban Beijing, China","volume":"41","author":"Dong","year":"2007","journal-title":"Atmos. Environ."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"245","DOI":"10.1016\/j.agee.2011.03.012","article-title":"Ammonia emissions from pig houses: Influencing factors and mitigation techniques","volume":"141","author":"Philippe","year":"2011","journal-title":"Agric. Ecosyst. Environ."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1016\/j.anifeedsci.2011.04.058","article-title":"Greenhouse gas emission profiles of European livestock sectors","volume":"166","author":"Lesschen","year":"2011","journal-title":"Anim. Feed Sci. Technol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"272","DOI":"10.1016\/j.biosystemseng.2011.08.007","article-title":"Air exchanges and indoor carbon dioxide concentration in Australian pig buildings: Effect of housing and management factors","volume":"110","author":"Banhazi","year":"2011","journal-title":"Biosyst. Eng."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"428","DOI":"10.1016\/j.apr.2016.11.003","article-title":"Evaluation of two indoor air pollution abatement techniques in forced-ventilation fattening pig barns","volume":"8","author":"Mostafa","year":"2017","journal-title":"Atmospheric Pollut. Res."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"41","DOI":"10.13031\/2013.24121","article-title":"Identification of risk factors for sub-optimal housing conditions in Australian piggeries: Part 3. Environmental parameters","volume":"14","author":"Banhazi","year":"2008","journal-title":"J. Agric. Saf. Health"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Panchasara, H., Samrat, N.H., and Islam, N. (2021). Greenhouse gas emissions trends and mitigation measures in Australian agriculture sector\u2014A review. Agriculture, 11.","DOI":"10.3390\/agriculture11020085"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"221","DOI":"10.1016\/S2095-3119(16)61372-2","article-title":"Greenhouse gas emissions from pig and poultry production sectors in China from 1960 to 2010","volume":"16","author":"Wang","year":"2017","journal-title":"J. Integr. Agric."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"126572","DOI":"10.1016\/j.jclepro.2021.126572","article-title":"Investigating historical dynamics and mitigation scenarios of anthropogenic greenhouse gas emissions from pig production system in China","volume":"296","author":"Chen","year":"2021","journal-title":"J. Clean Prod."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1038\/s41467-018-03308-7","article-title":"Multi-indicator sustainability assessment of global food systems","volume":"9","author":"Chaudhary","year":"2018","journal-title":"Nat. Commun."},{"key":"ref_30","unstructured":"R\u00f6\u00f6s, E., and Nylinder, J. (2013). Uncertainties and Variations in the Carbon Footprint of Livestock Products, Department of Energy and Technology, Swedish University of Agricultural Sciences."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1016\/j.livsci.2007.09.003","article-title":"Ammonia and greenhouse gas emissions from a straw flow system for fattening pigs: Housing and manure storage","volume":"112","author":"Amon","year":"2007","journal-title":"Livest. Sci."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"558","DOI":"10.1108\/CAER-04-2017-0063","article-title":"Marginal abatement cost of agricultural carbon emissions in China: 1993\u20132015","volume":"10","author":"Wu","year":"2018","journal-title":"China Agric. Econ. Rev."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1393","DOI":"10.1016\/S2095-3119(13)60624-3","article-title":"Research on spatial-temporal characteristics and driving factor of agricultural carbon emissions in China","volume":"13","author":"Yun","year":"2014","journal-title":"J. Integr. Agric."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1632","DOI":"10.1016\/j.atmosenv.2008.12.015","article-title":"Comparison of models used for national agricultural ammonia emission inventories in Europe: Litter-based manure systems","volume":"43","author":"Reidy","year":"2009","journal-title":"Atmos. Environ."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"129956","DOI":"10.1016\/j.jclepro.2021.129956","article-title":"Artificial intelligence in animal farming: A systematic literature review","volume":"331","author":"Bao","year":"2022","journal-title":"J. Clean. Prod."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1016\/j.jhazmat.2016.12.010","article-title":"A prediction model of ammonia emission from a fattening pig room based on the indoor concentration using adaptive neuro fuzzy inference system","volume":"325","author":"Xie","year":"2017","journal-title":"J. Hazard. Mater."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1546","DOI":"10.1002\/ep.12604","article-title":"Investigations of energy consumption and greenhouse gas emissions of fattening farms using artificial intelligence methods","volume":"36","author":"Shamshirband","year":"2017","journal-title":"Environ. Prog. Sustain. Energy"},{"key":"ref_38","unstructured":"Rojas, R. (2013). Neural Networks: A Systematic Introduction, Springer Science & Business Media."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"577","DOI":"10.1002\/ep.12448","article-title":"Prediction of output energies for broiler production using linear regression, ANN (MLP, RBF), and ANFIS models","volume":"36","author":"Amid","year":"2017","journal-title":"Environ. Prog. Sustain. Energy"},{"key":"ref_40","unstructured":"Fritsch, S., and Guenther, F. (2021, November 15). Neuralnet: Training of Neural Networks. R Package Version 1, 33. Available online: https:\/\/CRAN.R-project.org\/package=neuralnet."},{"key":"ref_41","unstructured":"Riedmiller, M. (2021, December 07). Rprop-Description and Implementation Details. Available online: http:\/\/www.inf.fu-berlin.de\/lehre\/WS06\/Musterererkennung\/Paper\/rprop.pdf."},{"key":"ref_42","first-page":"6","article-title":"Measurement of odour and greenhouse gas emissions in two swine farrowing operations","volume":"49","author":"Zhang","year":"2007","journal-title":"Can. Biosyst. Eng."},{"key":"ref_43","unstructured":"Cargill, C., and Skirrow, S.C. (1997). Air Quality in Pig Housing Facilities, Post Graduate Foundation in Veterinary Science, University of Sydney."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"3697","DOI":"10.1016\/S1352-2310(99)00128-4","article-title":"Production of carbon dioxide in a fattening pig house under field conditions. II. Release from the manure","volume":"33","author":"Ni","year":"1999","journal-title":"Atmos. Environ."},{"key":"ref_45","first-page":"77N","article-title":"Temperature, air humidity and air pollution levels in farrowing or weaner pig houses","volume":"14","author":"Nicks","year":"1993","journal-title":"Pig News Inf."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"113","DOI":"10.1016\/j.atmosenv.2017.02.033","article-title":"Factors and characteristics of ammonia, hydrogen sulfide, carbon dioxide, and particulate matter emissions from two manure-belt layer hen houses","volume":"156","author":"Ni","year":"2017","journal-title":"Atmos. Environ."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1016\/j.biosystemseng.2014.04.005","article-title":"Effects of different air inlets on indoor air quality and ammonia emission from two experimental fattening pig rooms with partial pit ventilation system\u2014Summer condition","volume":"122","author":"Zong","year":"2014","journal-title":"Biosyst. Eng."},{"key":"ref_48","doi-asserted-by":"crossref","unstructured":"Arulmozhi, E., Basak, J.K., Sihalath, T., Park, J., Kim, H.T., and Moon, B.E. (2021). Machine Learning-Based Microclimate Model for Indoor Air Temperature and Relative Humidity Prediction in a Swine Building. Animals, 11.","DOI":"10.3390\/ani11010222"},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Fernandez, M.D., Losada, E., Ortega, J.A., Arango, T., Ginzo-Villamayor, M.J., Besteiro, R., Lamosa, S., Barrasa, M., and Rodriguez, M.R. (2020). Energy, production and environmental characteristics of a conventional weaned piglet farm in north west spain. Agronomy, 10.","DOI":"10.3390\/agronomy10060902"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"106259","DOI":"10.1016\/j.compag.2021.106259","article-title":"Machine learning for improvement of thermal conditions inside a hybrid ventilated animal building","volume":"187","author":"Gautam","year":"2021","journal-title":"Comput. Electron. Agric."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/8\/2910\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T22:51:27Z","timestamp":1760136687000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/8\/2910"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,4,11]]},"references-count":50,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2022,4]]}},"alternative-id":["s22082910"],"URL":"https:\/\/doi.org\/10.3390\/s22082910","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,4,11]]}}}