The objectives of this study were 1)
\nto investigate if there were differences in the relation
\nbetween temperature and reproductive performance
\ntraits in 2 different sow lines, a Yorkshire line producing
\nmainly in temperate climates and a Large White
\nline producing mainly in warm climates, and 2) to determine
\nthe upper critical temperature (UCT) for the
\nreproductive performance of these 2 lines. Sows are
\nexposed to heat stress when temperature exceeds the
\nUCT of the thermo-neutral zone. Data included 32,631
\nobservations on reproductive performance from 11,935
\nsows on 20 farms in Spain, collected from 2003 to 2005.
\nSows belonged to 2 different purebred sow lines, named
\nD (Yorkshire sow line, producing mainly in temperate
\nclimates) and I (Large White sow line, producing
\nmainly in warm climates). Only first insemination records
\nper parity were used and were combined with the
\nmaximum outside temperature at day of insemination.
\nUpper critical temperatures were studied for 3 reproduction
\ntraits: farrowing rate (0 or 1), litter size (range
\nfrom 1 to 25), and total number of piglets born per first
\ninsemination (combination of farrowing rate and litter
\nsize, range from 0 to 25). Data were corrected for fixed
\neffects, which included parity, service sire, and an interaction
\nbetween farm and year. Corrected data were
\nused as observations in the models to study the effect of
\noutside temperature on reproductive performance. Two
\nmodels were compared for goodness of fit: a linear regression
\nmodel and a plateau-linear model with the plateau
\nrepresenting the thermo-neutral zone and a linear
\ndecrease above that zone. Farrowing rate of I-line sows
\nwas not affected by temperature. For litter size and
\ntotal number born per first insemination of I-line sows
\nno UCT could be estimated. These traits were linearly
\naffected by temperature. For all 3 reproduction traits of
\nthe D-line the best model was the plateau-linear model;
\nthe UCT for the D-line sows was estimated to be 19.2\u00b0C
\nfor farrowing rate, 21.7\u00b0C for litter size, and 19.6\u00b0C for
\ntotal number born per first insemination. The decrease
\nin reproductive performance of I-line sows with increasing
\noutside temperature was less than in D-line sows.
\nFrom this study it can be concluded that there are
\ndifferences in heat stress tolerance between sow lines
\nas measured by the differences in reproductive performance.
\nThese differences are an indication of genetic
\ndifferences in heat stress tolerance in sow lines.<\/p>\n","protected":false},"excerpt":{"rendered":"
The objectives of this study were 1) to investigate if there were differences in the relation between temperature and reproductive performance traits in 2 different sow lines, a Yorkshire line producing mainly in temperate climates and a Large White line producing mainly in warm climates, and 2) to determine the upper critical temperature (UCT) for […]<\/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":[8882,2854,12251,562,5886,103,7846,3804,269,2318,5620,818,1318,10859,14784,63,14,126,89,16262,17743,27282,5177,4199,12242,1533,104,6774,96,110,20911,99,18011,6775,4176],"class_list":["post-4068","post","type-post","status-publish","format-standard","hentry","category-production","tag-al","tag-bin","tag-born","tag-farms","tag-farrow","tag-farrowing","tag-farrowing-rate","tag-genetic","tag-heat","tag-heat-stress","tag-insemination","tag-litter","tag-litter-size","tag-nat","tag-ness","tag-performance","tag-pig","tag-piglet","tag-piglets","tag-pl","tag-prod","tag-production","tag-purebred","tag-reproductive-performance","tag-service","tag-size","tag-sow","tag-sow-line","tag-sows","tag-stress","tag-t","tag-temperature","tag-tot","tag-upper-critical-temperature","tag-yorkshire"],"_links":{"self":[{"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/posts\/4068","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=4068"}],"version-history":[{"count":0,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/posts\/4068\/revisions"}],"wp:attachment":[{"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/media?parent=4068"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/categories?post=4068"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/tags?post=4068"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}