{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/20551"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/20551","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Factors influencing aggression in newly mixed pigs","abstract":"996 pigs were used to understand the effects of aggression on growth in swine, the role of previous experience on the level of aggression, and the basis on which a pig accesses recognition and familiarity when mixed with an unfamiliar pig. The hypothesis that fighting in newly mixed pigs is proximately triggered by an innate response to fight unfamiliar pigs as opposed to an alternative hypothesis that fighting is triggered by unknown dominance status was also addressed. Growth over a 2 week period was negatively effected when mixing near market weight pigs (average wt. 85.1 kg). Time spent eating, lying and standing were similar across all treatment groups by day 8 (P $>$.05), however time spent fighting for Mixed pigs continued to be higher than other treatments (P $>$.01). In a trial using 6 and 10 week old pigs, time spent fighting (TF), total number of fights and the winner loser of an encounter among unfamiliar dyads in a neutral pen during a 2 h period was not influenced by their previous dominance ranks (P $<$.10). Six week old pigs differed from 10 week pigs in TF (raw means 758 and 421 sec/2 h period respectively; P $<$.01). TF was positively correlated with the difference in weight between the paired pigs (maximum difference 6.2 kg; P $<$.05). Newly mixed pigs access strangeness based on familiarity gained through previous association as opposed to recognition based on phenotypic kin recognition. Pigs fought more if reared apart than separately (252 $\\sp{\\rm \\ a}$ 33 sec vs 67 $\\sp{\\rm \\ a}$ 45 sec respectively; P $<$.0001), but time spent fighting was not different between related or unrelated dyads. An attempt to exchange familiarity (FX) between two unfamiliar pigs prior to mixing was unsuccessful in eliminating aggression during a 2 h mixing period. FX pigs were pre-exposed to each other while one of the pair was under the influence of anesthesia. FX pigs were no different from Negative Control pigs (NC) or Sham Controls (SC) in time spent investigating each other or for any of the fighting parameters measured. FX pigs may have gained some familiarity during pre-exposure periods since they had a higher frequency of mounting during the 2 h mixing period then the NC and SC pigs (P $<$.01). (Abstract shortened with permission of author.)","abstract_html":"996 pigs were used to understand the effects of aggression on growth in swine, the role of previous experience on the level of aggression, and the basis on which a pig accesses recognition and familiarity when mixed with an unfamiliar pig. The hypothesis that fighting in newly mixed pigs is proximately triggered by an innate response to fight unfamiliar pigs as opposed to an alternative hypothesis that fighting is triggered by unknown dominance status was also addressed. Growth over a 2 week period was negatively effected when mixing near market weight pigs (average wt. 85.1 kg). Time spent eating, lying and standing were similar across all treatment groups by day 8 (P $&gt;$.05), however time spent fighting for Mixed pigs continued to be higher than other treatments (P $&gt;$.01). In a trial using 6 and 10 week old pigs, time spent fighting (TF), total number of fights and the winner loser of an encounter among unfamiliar dyads in a neutral pen during a 2 h period was not influenced by their previous dominance ranks (P $&lt;$.10). Six week old pigs differed from 10 week pigs in TF (raw means 758 and 421 sec/2 h period respectively; P $&lt;$.01). TF was positively correlated with the difference in weight between the paired pigs (maximum difference 6.2 kg; P $&lt;$.05). Newly mixed pigs access strangeness based on familiarity gained through previous association as opposed to recognition based on phenotypic kin recognition. Pigs fought more if reared apart than separately (252 <span class=\"etd-inline-math\">\\sp{\\rm  a}</span> 33 sec vs 67 <span class=\"etd-inline-math\">\\sp{\\rm  a}</span> 45 sec respectively; P $&lt;$.0001), but time spent fighting was not different between related or unrelated dyads. An attempt to exchange familiarity (FX) between two unfamiliar pigs prior to mixing was unsuccessful in eliminating aggression during a 2 h mixing period. FX pigs were pre-exposed to each other while one of the pair was under the influence of anesthesia. FX pigs were no different from Negative Control pigs (NC) or Sham Controls (SC) in time spent investigating each other or for any of the fighting parameters measured. FX pigs may have gained some familiarity during pre-exposure periods since they had a higher frequency of mounting during the 2 h mixing period then the NC and SC pigs (P $&lt;$.01). (Abstract shortened with permission of author.)","abstract_has_math":true,"creators":["Stookey, Joseph Mitchell"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Animal Sciences","degree_department":null,"school":null,"contributors":["Gonyou, Harold W."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T12:42:31Z","date_published":"2011-05-07T12:42:31Z","updated_at":"2026-07-22T22:25:16Z","subjects":["Biology, Zoology","Agriculture, Animal Culture and Nutrition"],"languages":["eng"],"rights":["Copyright 1991 Stookey, Joseph Mitchell"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9136745","(UMI)AAI9136745"],"render_values":[{"text":"AAI9136745","href":null,"code":true},{"text":"(UMI)AAI9136745","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/20551","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Gonyou, Harold W."]},{"key":"dc:creator","label":"Author","values":["Stookey, Joseph Mitchell"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T12:42:31Z","10000-01-01","1991"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Animal Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Biology, Zoology","Agriculture, Animal Culture and Nutrition"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1991 Stookey, Joseph Mitchell"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9136745","(UMI)AAI9136745","http://hdl.handle.net/2142/20551"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["996 pigs were used to understand the effects of aggression on growth in swine, the role of previous experience on the level of aggression, and the basis on which a pig accesses recognition and familiarity when mixed with an unfamiliar pig. The hypothesis that fighting in newly mixed pigs is proximately triggered by an innate response to fight unfamiliar pigs as opposed to an alternative hypothesis that fighting is triggered by unknown dominance status was also addressed. Growth over a 2 week period was negatively effected when mixing near market weight pigs (average wt. 85.1 kg). Time spent eating, lying and standing were similar across all treatment groups by day 8 (P $>$.05), however time spent fighting for Mixed pigs continued to be higher than other treatments (P $>$.01). In a trial using 6 and 10 week old pigs, time spent fighting (TF), total number of fights and the winner loser of an encounter among unfamiliar dyads in a neutral pen during a 2 h period was not influenced by their previous dominance ranks (P $<$.10). Six week old pigs differed from 10 week pigs in TF (raw means 758 and 421 sec/2 h period respectively; P $<$.01). TF was positively correlated with the difference in weight between the paired pigs (maximum difference 6.2 kg; P $<$.05). Newly mixed pigs access strangeness based on familiarity gained through previous association as opposed to recognition based on phenotypic kin recognition. Pigs fought more if reared apart than separately (252 $\\sp{\\rm \\ a}$ 33 sec vs 67 $\\sp{\\rm \\ a}$ 45 sec respectively; P $<$.0001), but time spent fighting was not different between related or unrelated dyads. An attempt to exchange familiarity (FX) between two unfamiliar pigs prior to mixing was unsuccessful in eliminating aggression during a 2 h mixing period. FX pigs were pre-exposed to each other while one of the pair was under the influence of anesthesia. FX pigs were no different from Negative Control pigs (NC) or Sham Controls (SC) in time spent investigating each other or for any of the fighting parameters measured. FX pigs may have gained some familiarity during pre-exposure periods since they had a higher frequency of mounting during the 2 h mixing period then the NC and SC pigs (P $<$.01). (Abstract shortened with permission of author.)","Made available in DSpace on 2011-05-07T12:42:31Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9136745.pdf: 7230856 bytes, checksum: b492a5a560fab3e59246ab446cdf34f8 (MD5) Previous issue date: 1991","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:44:39Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:19:41-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"]},{"key":"dc:title","label":"Title","values":["Factors influencing aggression in newly mixed pigs"]}]}],"canonical_facts":{"dc:contributor":["Gonyou, Harold W."],"dc:creator":["Stookey, Joseph Mitchell"],"dc:date":["2011-05-07T12:42:31Z","10000-01-01","1991"],"dc:description":["996 pigs were used to understand the effects of aggression on growth in swine, the role of previous experience on the level of aggression, and the basis on which a pig accesses recognition and familiarity when mixed with an unfamiliar pig. The hypothesis that fighting in newly mixed pigs is proximately triggered by an innate response to fight unfamiliar pigs as opposed to an alternative hypothesis that fighting is triggered by unknown dominance status was also addressed. Growth over a 2 week period was negatively effected when mixing near market weight pigs (average wt. 85.1 kg). Time spent eating, lying and standing were similar across all treatment groups by day 8 (P $>$.05), however time spent fighting for Mixed pigs continued to be higher than other treatments (P $>$.01). In a trial using 6 and 10 week old pigs, time spent fighting (TF), total number of fights and the winner loser of an encounter among unfamiliar dyads in a neutral pen during a 2 h period was not influenced by their previous dominance ranks (P $<$.10). Six week old pigs differed from 10 week pigs in TF (raw means 758 and 421 sec/2 h period respectively; P $<$.01). TF was positively correlated with the difference in weight between the paired pigs (maximum difference 6.2 kg; P $<$.05). Newly mixed pigs access strangeness based on familiarity gained through previous association as opposed to recognition based on phenotypic kin recognition. Pigs fought more if reared apart than separately (252 $\\sp{\\rm \\ a}$ 33 sec vs 67 $\\sp{\\rm \\ a}$ 45 sec respectively; P $<$.0001), but time spent fighting was not different between related or unrelated dyads. An attempt to exchange familiarity (FX) between two unfamiliar pigs prior to mixing was unsuccessful in eliminating aggression during a 2 h mixing period. FX pigs were pre-exposed to each other while one of the pair was under the influence of anesthesia. FX pigs were no different from Negative Control pigs (NC) or Sham Controls (SC) in time spent investigating each other or for any of the fighting parameters measured. FX pigs may have gained some familiarity during pre-exposure periods since they had a higher frequency of mounting during the 2 h mixing period then the NC and SC pigs (P $<$.01). (Abstract shortened with permission of author.)","Made available in DSpace on 2011-05-07T12:42:31Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9136745.pdf: 7230856 bytes, checksum: b492a5a560fab3e59246ab446cdf34f8 (MD5) Previous issue date: 1991","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:44:39Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:19:41-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"],"dc:identifier":["AAI9136745","(UMI)AAI9136745","http://hdl.handle.net/2142/20551"],"dc:language":["eng"],"dc:rights":["Copyright 1991 Stookey, Joseph Mitchell"],"dc:subject":["Biology, Zoology","Agriculture, Animal Culture and Nutrition"],"dc:title":["Factors influencing aggression in newly mixed pigs"],"dc:type":["text"],"thesis:degree_discipline":["Animal Sciences"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:16Z"}