The evolutionary strategy adopted by the pig is to produce a large number of relatively undeveloped offspring. Such a\u00a0strategy demands that relatively little investment is made in each individual piglet pre-natally, and that piglets which are\u00a0surplus to resources should die at an early stage with least prejudice to their littermates. Thus, inherent variation in neonatal\u00a0competitiveness is an advantage and survival of the strongest is promoted. Genetic selection strategies resulting in increased\u00a0litter size and reduced physiological maturity at birth have compounded these effects, making piglet mortality an intractable\u00a0problem. Records of piglet mortality in commercial units indicate that most deaths of liveborn piglets are attributed to\u00a0crushing and starvation, but these ultimate causes are often secondary to the effects of perinatal hypothermia. Piglet survival\u00a0is the outcome of complex interactions between the sow, the piglet and the environment. Commercial strategy has focused on\u00a0improving the farrowing environment to modify sow behaviour and increase human intervention. However, concerns about\u00a0the welfare implications of confining sows in farrowing crates may limit the use of such approaches in the future and change\u00a0the focus towards genetic selection for characteristics in both the dam and offspring which promote survival. Methods of\u00a0improving the inherent viability of the piglet, for example by increasing birth weight, neonatal vigour and thermoregulatory\u00a0ability, have been commercially less effective to date, with intra-partum hypoxia exerting an overwhelming influence. A\u00a0better understanding of neonatal and maternal physiology in relation to placental transfer of nutrients, regulation of the\u00a0parturition process, colostrum transfer and expression of appropriate maternal behaviour is required for the development of\u00a0effective future solutions.<\/p>\n
Sandra Edwards<\/span><\/p>\n","protected":false},"excerpt":{"rendered":" The evolutionary strategy adopted by the pig is to produce a large number of relatively undeveloped offspring. Such a\u00a0strategy demands that relatively little investment is made in each individual piglet pre-natally, and that piglets which are\u00a0surplus to resources should die at an early stage with least prejudice to their littermates. Thus, inherent variation in neonatal\u00a0competitiveness […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[19,928],"tags":[3814,26550,26096,27050,103,1468,3804,2771,14,26341,26222,23609,27281],"class_list":["post-15170","post","type-post","status-publish","format-standard","hentry","category-pork-insight-articles","category-welfare","tag-competitive","tag-crush","tag-edwards","tag-effect-of-hypothermia-on-piglet-survival","tag-farrowing","tag-farrowing-crates","tag-genetic","tag-iron","tag-pig","tag-sandra-edw","tag-sandra-edwards","tag-spring","tag-welfare"],"_links":{"self":[{"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/posts\/15170","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=15170"}],"version-history":[{"count":5,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/posts\/15170\/revisions"}],"predecessor-version":[{"id":16101,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/posts\/15170\/revisions\/16101"}],"wp:attachment":[{"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/media?parent=15170"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/categories?post=15170"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/tags?post=15170"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}