Brent Jones from South West Ontario Veterinary Services, Aussies “Kick The Tires” On Group Lactation


Around the time of the Brexit induced UK general election there was some discussion of promoting legislation that would ban the use of farrowing crates. That was shelved for the election but that direction had resurfaced as DEFRA Secretary Theresa Villiers announced that DEFRA would entertain a phased in farrowing crate ban.  Unfortunately Group Lactation (GL) has had some challenges in maintaining performance equal to that acheived in farrowing crates. Transferring sows and their litters to group lactation after an initial period of farrowing crate housing (FC) has been perceived as a compromise for commercial production. Group lactation starting at 7 days post-partum would at least reduce the time sows spend in confinement, but the effects of early mixing on animal welfare and productivity requires examination.

These Australian researchers wanted to “kick the tires” on GL to see if indeed there were any flat spots. Two experiments were conducted on sows and piglets kept in GL from 7, 10 or 14 days post-partum, compared to FC.

  • Experiment 1 utilized 180 sows and 1887 piglets over 5-time replicates (n = 60 sow and litter units per treatment) comparing GL from 7 or 14 days post-partum to FC.
  • Experiment 2 utilized 108 sows and 1179 piglets studied over 3-time replicates (n = 36 sow and litter units per treatment) comparing GL from 10 or 14 days post-partum to FC.
  • All sows farrowed in FC and then group lactation sows were transferred to pens (one pen of 5 sows at 8.4 m2/sow and one pen of 7 sows at 8.1 m2/sow, per GL treatment and replicate) with their litters at 7 (GL7), 10 (GL10) or 14 (GL14) days post-partum. Farrowing crate sows and their litters remained in their FC.

The researchers found the following:

  • Piglet mortality was greater in GL7 (17 ± 1.8%) and GL10 treatments (12 ± 0.9%) compared to GL14 (8.3 ± 1.8% P ≤ 0.001 and 8.1 ± 0.9% P ≤ 0.001 in experiments 1 and 2)
  • Piglet mortality was greater in GL overall compared to FC (2.7 ± 1.5% and 1.8 ± 0.9% in FC in experiments 1 and 2; P ≤ 0.001).
  • Piglet weaning weight in GL7 was lighter than GL14 piglets (P < 0.001), whereas GL10 and GL14 did not differ (P > 0.05).
  • Piglet weaning weight was overall lighter in GL than in FC (P ≤ 0.01).
  • Sows from GL7 were heavier at weaning (P = 0.001), and GL10 sows tended to be heavier at weaning (P = 0.08), than GL14 and FC sows.
  • Post-mixing, sow cortisol (P ≤ 0.01), and sow and piglet injuries (P ≤ 0.02) were greater in GL than FC.
  • Treatment had no effect on sow feed intake or reproductive performance (P > 0.05).

Take Home Messages:

  • Based on this experimental design, the perceived welfare advantage for movement to group lactation was countered with a costs associated with increased piglet mortality and injuries after mixing, and reduced piglet growth.
  • Sometimes “The needs of the many outweigh the needs of the few.” Spock – Wrath of Kahn

Ref: Verdon M, Morrison RS, Rault JL.  The welfare and productivity of sows and piglets in group lactation from 7, 10 or 14 days postpartum.  J Anim Sci. 2020 Feb 1. pii: skaa037. doi: 10.1093/jas/skaa037. 



  1. Some of My clients group lactate gilts starting from 14 – 21 days days till weaning at 28 days – Gilt progeny are as heavy or much heavier than sow progeny – works well with not so brilliant weaner accommodation- We use IBC with a hole for suckers & Straw -finisher style self feeder – sows and suckers eat sow feed. 3 gilts a pen is fine. Very cheap – saved big spend on better quality weaner shed or more farrowing crates crates

    The gilts have reduced RTS .

    Sow welfare in farrow crate is high if sows are cool, prostaglandins are banned (tends to stir them up), oxytocin only used on open cervix, fostering post day 1 is minimal minimal minimal ( fostering upsets donor & recipient litters) – Good stock people have sheds that when you walk in the recumbent sow partly opens one eye – in high foster / hormone sheds the sows in my opinion are very agitated & stressed –

    The Welfare Gurus tend not to look at these issues – Just salivary cortisol – I would trust a good stock person before I would trust the word of a Welfarist with a salivary cortisone assay