Pre-Farrowing Health and Welfare Asessment of Sows

Abstract

<p>A total of 1103 primi- and multiparous sows from two nucleus farms were recorded in late spring (N=558 sows) of 2017 and late summer (N=545 sows) of 2018. These sows were recorded for a range of health and welfare traits from the transfer to farrowing shed until weaning. Data obtained from electronic sow feeders during the gestation period were used to generate feed intake and feeding behavior traits and establish possible associations with health and welfare traits. These data were recorded in 2015, from 2847 predominantly (90.5%) F1 sows and from 540 pure bred sows from two locations.</p> <p>The aim of this project was to determine the most useful measures for identifying sows with the risk of undesirable outcome during the gestation period and around farrowing through to weaning, for the purpose of establishing a potential monitoring system to improve management of at risk sows. The second aim was to identify which of these traits were heritable and potentially useful in a breeding program context. The third aim was to evaluate the implications of variation in genetic merit in reproductive or performance traits for health and welfare outcomes.</p> <p>Using multivariate logistic regression, several predictors were related to undesirable farrowing and lactation outcomes, along with higher rate of premature removals. Predictors relating to body condition and ability to fit into the crate, appetite of sows, udder health (mastitis and injured or regressed teats) and physiological state of sows (respiration rate and haemoglobin levels) appeared to be the most informative to identify sows with higher risk of undesirable outcomes. Early detection of sows with urinary tract infection and the following treatment may reduce forced removals. The results obtained from the electronic sow feeder data (ESF) showed that cumulative missed or low intake feeding events were informative to predict the risk of undesirable outcomes. In addition, while sows in this study were considered to be healthy, correlations between ESF data and subsequent health and welfare outcomes suggested that ESF data can be useful for identifying sows which require further attention.</p> <p>In the genetic analysis of health and welfare traits it was demonstrated that traits related to appetite of sows (feed refusals before farrowing), udder health (mastitis, un-suckled and regressed teats), physiological state (respiration rate and rectal temperature) and size of the sow (caliper score, crate fit and teat access) were moderately heritable. Along with adjusting management practices, selection for traits related to health and welfare could potentially improve production performances and decrease forced removals. Variation in ESF phenotypes amongst individual sows reflected significant genetic variation in some of these traits. Traits related to feeding behaviour of gestating sows were moderately heritable, whereas heritability for feed intake itself was low to negligible. Thus, individual phenotypes constructed from ESF data could be useful for genetic evaluation purposes, but equivalent capabilities were not available for both ESF systems used in this study.</p>