Improving sow welfare and outcomes in the farrowing house by identifying early indicators from pre-farrowing assessment

摘要

This study identified a group of pre-farrowing predictors that could identify specific sows requiring additional care to reduce the risk of poor performance and premature removals. Poor outcomes reflect low performance during the farrowing and lactation periods and unanticipated sow removals. Since the period around farrowing has the highest risk for sow health issues, monitoring of sows in that time-period will improve both welfare and productivity. The aim of this study was to identify the most relevant risk factors for predicting poor outcomes and the implication for sow welfare. Identifying these factors could potentially enable management interventions to decrease incidences of compromised welfare or poor performance. Data from 1,103 sows sourced from two nucleus herds were recorded for a range of variables investigated as potential predictors of poor outcomes in the farrowing house. Poor outcomes (scored as binary traits) reflected three categories in a sow's lifecycle: farrowing, lactation, and removals. Univariate logistic regression was used to identify predictors in the first instance. Predictors from univariate analyses were subsequently considered together in multi-variate models. The least square means representing predicted probabilities of poor outcomes were then reported on the observed scale. Several predictors were significant across two different environments (farms) and for all three categories. These predictors included feed refusal (lack of appetite), crate fit, locomotion score, and respiration rate. Normal appetite compared to feed refusals reduced the risk of farrowing failure (13.5 vs. 22.2%, P = 0.025) and removals (10.4 vs. 20.4%, P < 0.001). Fit in the crate was significant (P < 0.001) for farrowing and lactation outcomes, and was more informative than parity. Sows with sufficient space had two to three times reduced risk of poor outcomes compared to restrictive crates relative to sow dimensions. Sows with good locomotion score pre-farrowing had two to three times less risk of farrowing failure (P = 0.025) and reduced piglet mortality (P < 0.001), weaned two piglets more relative to affected sows (P < 0.001), and were less likely to be removed before weaning (3.24 vs. 12.3%, P = 0.014). Sows with higher respiration rates had a significantly (P < 0.001) reduced risk of poor farrowing outcomes. This study demonstrated it is possible to predict poor outcomes for sows prior to farrowing, suggesting there are opportunities to decrease the risk of poor outcomes and increase overall sow welfare. Lay Summary Farrowing and lactation are the most vulnerable events in sows' lifecycle with high risk of compromised health. For at-risk sows, poor health could result in an increased level of stillborn piglets, a decreased number of weaned piglets, or premature removals of sows from the herd. This can potentially be avoided by identifying at-risk sows prior to farrowing, to enable effective management interventions, thereby improving sow welfare. Several risk factors are shown to be consistent in identifying sows with compromised health or welfare across two different management systems. These risk factors are low appetite before farrowing, low respiration rate, leg problems, and the sows' fit within the farrowing crate relative to their dimensions. This study suggested that at-risk sows may be identified; altering their subsequent management and treatment could result in higher performance and reduced risk of premature removals.