Review of Temporary Crating of Farrowing and Lactating Sows

Abstract

Temporary crating (TC) provides lactating sows with the opportunity to move more freely after crate opening a few days after parturition. The aim of this paper was to evaluate whether TC gives overall welfare improvement when compared to permanent crating or free farrowing. This review shows that when pens with TC allow the sows to turn during the majority of time in the farrowing unit, it is the pen design and period of confinement in a crate within it that influence the extent to which different functional and motivated behaviors can be fulfilled. This review also indicates that there are at least short-term benefits to sows when confinement is reduced, as shown by reported increases in motivated behaviors such as exploration and interactions with piglets when not permanently crated. It remains unclear whether there are any longer-term beneficial effects (until or beyond weaning) due to the paucity of studies. Furthermore, it is uncertain whether the observed short-term benefits translate to other welfare indicators. Research findings indicate no reduction in the frequency of stereotypies or body lesions and do not provide a clear answer regarding sow stress response when released from confinement. Compared to free farrowing, TC appears beneficial for reducing piglet mortality. The impact of the time of onset of TC on the farrowing process and piglet mortality have been inconsistent. While confinement before farrowing prevents nest building behavior, consequences of this for sow physiology have been ambiguous. Confining the sow briefly after farrowing may be the best compromise, allowing the sow to perform motivated nest-building behavior, but the risks of crushing during the unconfined farrowing period may increase. Subsequent crate reopening seems to increase piglet mortality but only if done earlier than 3–5 days after farrowing. The review also provides methodological considerations, a proposal for consistent and accurate terminology when describing systems and highlights gaps of knowledge. In conclusion, TC is a step forward to better pig welfare compared to the farrowing crate, as it allows some freedom of movement for sows without impairing piglet welfare. However, more comprehensive research is needed to draw sound conclusions as to whether TC is a viable transition from permanent crating to free farrowing.

Welfare of pigs on farm

“…For sows which farrow overnight, this may be several hours after the last piglet is born. The available information regarding these different options has recently been the subject of a detailed scientific review (Goumon et al., 2022), where the pertinent scientific references can be found. The key evidence is summarised in the following sections.…”

“…The consequences of the time at which temporary crating is imposed for the farrowing process are also inconsistent. Most recent studies report no difference in farrowing duration (5/7 studies; see Goumon et al, 2022) or the number of stillborn piglets (6/9 studies) when sows were confined for 1 or more days before expected farrowing in comparison to animals not confined for the period before and during farrowing.…”

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

“…Several authors have shown that sow mature weight and therefore sow size is increasing, as a correlated response with breeding objective traits ( Rauw et al, 1998 ; Hermesch, 2010 ). Given that crate sizes have remained constant ( Goumon et al, 2022 ), this places modern sows at higher risk of poor farrowing or lactation outcomes. The main justification for using farrowing crates is to prevent the crushing of piglets by slowing sows when lying down ( Alonso-Spilsbury et al, 2007 ; Peltoniemi et al, 2021 ).…”

Transitioning from crates to free farrowing: A roadmap to navigate key decisions

“…prohibiting farrowing crates, is the temporary crate [TC; (7)]. The majority of TCs involve the use of a modified farrowing crate intended to allow the sow to be loose pre-farrowing, before restraining her during farrowing, then opening the crate (typically at 3-7 days post-farrowing) to allow the sow greater movement possibilities for the rest of lactation.…”

“…Research into the welfare detriments associated with farrowing crates, biological needs of sows and piglets, and designs of alternatives has been extensively reviewed (4)(5)(6)(7)(8). Some publications have highlighted benefits of using higher welfare farrowing and lactation systems and practices (hereafter referred to as alternatives), including benefits for piglet growth and cognitive development (9)(10)(11), and for sow hormonal status, ease of farrowing [for review-(12)] and colostrum quality (13).…”