Odour emission from pig production facilities causes serious nuisance in the surrounding areas, and should therefore be reduced. Odour is mainly generated by the microbial conversion of feed in the intestinal tract of pigs and by microbial conversion of pigs\u2019 excreta under anaerobic conditions in manure storages. Protein is an important dietary compound that could be altered to reduce odour emission. Reducing protein or nitrogen concentration in excreta decreases the availability of substrates that microbes can metabolise to odorous compounds. It is clear from the literature that ammonia from animal production facilities can be decreased considerably by reducing the amount of protein in the diet and at the same time supplementing most essential amino acids to balance the amino acid pattern and to maintain animal performance (Hobbs et al., 1996; Canh et al., 1998b; Zervas and Zijlstra, 2002; Portejoie et al., 2004). Scientists mainly focused on certain specific odorous compounds in the manure or in the odorous air and little attention has been given to the effect of dietary crude protein levels on odour emission measured by olfactometry. Odour measured by olfactometry is evaluated through its strength (odour concentration and odour intensity) and offensiveness (odour hedonic value). The objective of this study was to determine the effects of dietary crude protein level on odour emission, odour intensity, hedonic tone, and ammonia emission from pig manure and on manure composition (pH, total nitrogen, ammonium, volatile fatty acids, indolic, phenolic and sulphur-containing compounds). An experiment was conducted with growing pigs in a randomised complete-block design with three treatments in six blocks. Treatment groups were 12%, 15% and 18% crude protein diets. Barley was exchanged for soya-bean meal. Crystalline amino acids were included in the 12% crude protein diet up to the level of pigs\u2019 requirement; the same amount of Crystalline amino acids were added to the 15% and 18% crude protein diets. Pigs with an initial body weight of 36.5 \u00b1 3.4 kg were individually penned in partly slatted floor pens and offered a daily feed allowance. Faeces and urine of each pig were accumulated together in a separate manure pit under the slatted floor. After an adaptation period of 2 weeks, the manure pits were cleaned and manure was collected. In the 5th week of the collection period, air samples for odour and ammonia analyses, and manure samples were collected directly from each manure pit. Air samples were analysed for odour concentration and for hedonic value and intensity above odour detection threshold. Manure samples were analysed for volatile fatty acids, and indolic, phenolic and sulphurous compounds, ammonium and total nitrogen concentrations. It was concluded that reducing dietary crude protein from 18% to 12% lowered odour emission and ammonia emission from pig manure by 80% and 53%, respectively. Therefore a reduction of dietary crude protein and at the same time providing essential amino acids is an option to reduce odour emission as well as ammonia emission from pig manure.<\/p>\n","protected":false},"excerpt":{"rendered":"
Odour emission from pig production facilities causes serious nuisance in the surrounding areas, and should therefore be reduced. Odour is mainly generated by the microbial conversion of feed in the intestinal tract of pigs and by microbial conversion of pigs\u2019 excreta under anaerobic conditions in manure storages. Protein is an important dietary compound that could […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[930],"tags":[1809,5361,8882,580,229,659,640,364,5117,1972,2235,19644,577,1287,23694,4663,313,27280,2851,6904,46,171,20007,651,517,18898,169,6004,974,14784,187,198,200,63,14,266,1635,33,16262,17743,27282,730,816,803,4599,309,20911,4874,1579,26223,18011,52,1213,1301,10806],"class_list":["post-4116","post","type-post","status-publish","format-standard","hentry","category-production","tag-acid","tag-adaptation","tag-al","tag-amino-acids","tag-ammonia","tag-anaerobic","tag-animal","tag-barley","tag-body-weight","tag-condition","tag-conversion","tag-dd","tag-diet","tag-diets","tag-dir","tag-don","tag-emission","tag-environment","tag-fat","tag-fee","tag-feed","tag-floor","tag-gh","tag-growing-pig","tag-growing-pigs","tag-hobbs","tag-manure","tag-manure-pit","tag-manure-storage","tag-ness","tag-nitrogen","tag-odor","tag-odour","tag-performance","tag-pig","tag-pig-manure","tag-pig-production","tag-pigs","tag-pl","tag-prod","tag-production","tag-protein","tag-protein-level","tag-slatted-floor","tag-stall","tag-storage","tag-t","tag-tan","tag-test","tag-the-effects","tag-tot","tag-treatment","tag-urine","tag-weight","tag-zijlstra"],"_links":{"self":[{"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/posts\/4116","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/comments?post=4116"}],"version-history":[{"count":0,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/posts\/4116\/revisions"}],"wp:attachment":[{"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/media?parent=4116"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/categories?post=4116"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/tags?post=4116"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}