Practical experiences with loose-housed sows during mating

A survey of 38 farmers who turn sows loose early during the insemination period and the first weeks of gestation, known as “breed and release,” was conducted to identify critical points and keys to the success of this practice. The results show that combining good productive performance, better working conditions, and animal welfare is possible.

The issue of reducing or banning animal confinement is increasingly prominent in social debates related to animal welfare. In France, as in the rest of the European Union, the 2012 regulation require gestating sows to be housed loose and in groups one month after artificial insemination (AI) and up to one week before farrowing. Although there is no legislation regulating sows being loose in lactation, there is an increasing trend to implement free farrowing on farms.

Following a similar logic, some farmers are reducing or even eliminating the period of sow confinement during the mating phase. This strategy, known as “loose sows during breeding” or “breed and release,” although still an uncommon practice, is attracting growing interest. To identify the key factors for success in managing loose sows during this phase, the Brittany region's Chamber of Agriculture surveyed 38 farmers who already do this. Farmers wishing to implement this practice on their farms can find advice sheets (in French) from the Chamber of Agriculture about the adaptations in management, reproductive performance, and housing types.

Three strategies for the timing of sow release

The results of the surveys identified three strategies implemented by farmers the week after weaning (see diagram 1):

1. LIBIA: Sows are kept in standard stalls from weaning til the final insemination. Then they are released and grouped within six days of the final insemination (15 out of 38 farms).
2. LIBSEVIA: Sows are housed loose and in groups from weaning, then placed in stalls during the insemination period, and released into the group again. Farmers explain that they take advantage of the stress generated by grouping them together to induce estrus and facilitate detection (sows mounting each other). Sows are in the stalls for about a week during the insemination period and then released immediately or, at the latest, within six days after the final insemination (11 out of 38 farms).
3. LIBSEV: Sows are grouped from weaning and are in the stalls only for artificial insemination, for a maximum of half a day. Therefore, the sows remain in a group for the entire breeding and gestation periods (12 farms out of 38).

Diagram 1. Summary of practices and strategies of the surveyed farms.

Practice	Number of farms	Type of housing	Description
LIBIA Loose after AI
	15	• 15/15 slat	Crated period (up to a maximum of six days after AI) for recovery of sow body condition. Early transfer to the gestation barn.
LIBSEV Loose after weaning
	12	• 6 straw • 3 straw/slat • 3 slat	Crated only during artificial insemination, with a maximum of half a day per insemination. Hierarchy established from weaning Grouping stress: favors the onset of estrus. Rapid detection of estrus with sows in a group
LIBSEVIA Loose after weaning, crated during AI, and loose again after AI
	11	• 3 straw/slat • 8 slat	Limited crating (2-3 days, maximum 6 days after AI). Prevents sows mounting each other during estrus. Hierarchy established from weaning. Grouping stress: improves estrus onset. Rapid detection of estrus with sows in a group.

Precautions to take during the grouping process

Sow grouping is a crucial time to ensure success in this type of management. It is especially important to avoid grouping sows during the highest risk phase, between the 12th and 18th day of gestation. Therefore, it is recommended to form groups before this period, either immediately after weaning or just after inseminations. In this way, aggressions related to establishing hierarchy happen earlier. If aggressions occur at weaning, they have the benefit of stimulating the onset of estrus.

Regarding grouping strategies, it is preferable to form groups of homogeneous sows in terms of body condition, ideally by parity, and to avoid mixing gilts with multiparous sows.

Most of the farmers surveyed perform artificial inseminations with the sows crated. Three of them perform inseminations with loose sows. Ultrasound scans, for the most part, are also performed with loose sows. It is noteworthy that half of the respondents perform ultrasounds with the sows loose, while the other half crate them during this procedure.

Advantages and critical points to consider

The farmers surveyed highlighted numerous benefits of loose sow management in the breeding phase. Many emphasize the enjoyment of seeing sows interact in groups as well as the positive impact on their animals' welfare. Those who group sows from weaning report improved estrus onset, attributed to the stress generated during grouping.

However, some farmers report aggressive behavior among sows, especially when integrating gilts into the group. Despite this, a quarter of the farmers consider that their sows are calmer and that this practice improves the relationship between the farmer and the animals. A third of the respondents also noted an improvement in their working conditions, thanks to the reduction in moving the animals and the time spent removing feces from the corridor at the back of the stalls.

On the other hand, existing facilities can be an obstacle to implementing this management, mainly due to designs that are not adapted to the system's needs. Gestation with loose sows does not require the use of bedding but it does not preclude it. Farmers who choose to use straw report sows that are less aggressive because they are busy rooting. Slatted facilities are chosen because of good sow hygiene; however, this flooring type can become slippery in wet conditions, increasing the risk of falls and lameness. The design of the pens or rooms is another critical point (boar exposure, access to pits, etc.).

Finally, 25% of the respondents consider that their loose sows show good production results (see Table 1). All the farmers consulted were satisfied with this management and none contemplated returning to the previous system.

Table 1. Reproductive performance: Average results of 12 farmers surveyed.

While still not widespread, this type of sow management is set to gain popularity as animal welfare legislation evolves, as evidenced by reforms planned in Germany and Denmark for 2028 and 2035, respectively. In addition, an EFSA report published in 2022 recommended eliminating the use of stalls in the mating phase, which will serve as the scientific basis for developing the next regulation.

This study, conducted between 2021 and 2024, was financially supported by PRDA, Porc Armor Evolution, Porélia, and Eureden, and benefited from the exchange of results of a survey conducted by Evel'Up. Thank you to the farmers who participated in this study for the quality of the exchanges and their confidence.