{"id":5652,"date":"2008-01-01T01:01:01","date_gmt":"2008-01-01T01:01:01","guid":{"rendered":"http:\/\/export.maxmaziy.php.nixsolutions.com\/?p=983"},"modified":"2012-01-03T14:51:00","modified_gmt":"2012-01-03T20:51:00","slug":"visual-acuity-of-pigs-at-different-light-intensities","status":"publish","type":"post","link":"http:\/\/prairieswine.com\/rsc\/visual-acuity-of-pigs-at-different-light-intensities\/","title":{"rendered":"Visual acuity of pigs at different light intensities"},"content":{"rendered":"<p>In most West European countries pigs are housed indoors under low-light conditions. While former<br \/>\nDutch National legislation for pigs required 12 lx for 8 h per day, EU legislation requires 40 lx, so pigs<br \/>\nshould be able to distinguish small objects and subtle visual signals. However, limited scientific evidence<br \/>\nexists about the effects of light intensity (illumination) and object size on the pigs\u2019 ability to distinguish<br \/>\nvisual cues. We studied these two effects using operant conditioning with a Landolt-C symbol as shape<br \/>\ndiscriminator. Four Landolt-C symbols with different sizes (with gaps of, respectively, 10 mm(L10), 20 mm<br \/>\n(L20), 30 mm (L30) and 40 mm (L40)) were tested under 8 different illuminant levels (0.5, 3, 6, 12, 20, 30,<br \/>\n40 and 80 lx). Following a 4-week training period, 20 female 4-month-old pigs were tested in two batches<br \/>\nand the numbers of correct, hesitant and incorrect choices were recorded. Reduced illumination significantly<br \/>\nincreased the number of incorrect choices (P &lt; 0.05). Symbol size also had a significant effect (P &lt; 0.001);<br \/>\npigs made more mistakes with the two smaller symbols L10 (41.5%) and L20 (28.6%) compared to the<br \/>\nbigger symbols L30 (17.3%) and L40 (16.3%). Furthermore, pigs hesitated less with the smallest symbol<br \/>\nL10 (4.5%) compared to L20, L30 and L40 (17.3, 22.3 and 23.0%, respectively; P &lt; 0.001). Visual acuity<br \/>\n(ability to distinguish details and shapes) varied from 0.001 to 0.03 and pigs failed to discriminate visual<br \/>\ncues below 20 mm. Results indicate that the detail of the visual cue (symbol size) has a more pronounced<br \/>\neffect on the pigs\u2019 ability to distinguish visual cues, compared to the illuminant level.<\/p>\n<p>For more information the full article can be found at <a href=\"http:\/\/journals.elsevierhealth.com\/periodicals\/applan\/issues\">http:\/\/journals.elsevierhealth.com\/periodicals\/applan\/issues<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>In most West European countries pigs are housed indoors under low-light conditions. While former Dutch National legislation for pigs required 12 lx for 8 h per day, EU legislation requires 40 lx, so pigs should be able to distinguish small objects and subtle visual signals. However, limited scientific evidence exists about the effects of light [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[928],"tags":[8882,1972,20007,111,9053,5381,10859,3465,14,33,16262,1533,20911,4874,1579,26223,6608],"class_list":["post-5652","post","type-post","status-publish","format-standard","hentry","category-welfare","tag-al","tag-condition","tag-gh","tag-health","tag-leg","tag-light","tag-nat","tag-pea","tag-pig","tag-pigs","tag-pl","tag-size","tag-t","tag-tan","tag-test","tag-the-effects","tag-visual-acuity-light-intensity-visual-cue-pigs"],"_links":{"self":[{"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/posts\/5652","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=5652"}],"version-history":[{"count":2,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/posts\/5652\/revisions"}],"predecessor-version":[{"id":11138,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/posts\/5652\/revisions\/11138"}],"wp:attachment":[{"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/media?parent=5652"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/categories?post=5652"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/tags?post=5652"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}