Reminiscing back to my familys 50-head pure-line sow herd in the 1980s, I recall we on occasion had a sow that barely fit into the farrowing Pig Crate. I can remember a particularly large Landrace sow, as wide and as long as the crate, that appeared quite uncomfortable. She ended up laying on multiple piglets.
I'm sure some of you may share a similar story. Now fast forward to 2020. One would think we would have the optimal farrowing crate size figured out. Yet I am not sure we do. There are around one million farrowing crates in the United States, and Tube Farrowing Crates are a sizable capital expense. Yet studying differences between farrowing crates can be challenging.
When evaluating different farrowing crates, generally each design or size should be represented within the same room. To further complicate things, research for piglet survival requires hundreds of replicates per treatment to achieve adequate statistical power.
Farrowing crate width
Farrowing crate width has not been shown to greatly impact piglet survival in large commercial studies. Ketchem and Rix (2013) evaluated three farrowing crate types where the sowing area was similar in length, yet some differences existed in width. In general, Solid Rod Farrowing Stalls width of 17 and 20 inches did not appear to greatly impact piglet survival. Keeping the sowing area the same, Vande Pol (2017) evaluated farrowing crate width using over 1,600 litters. The author reported no statistical differences for preweaning mortality between farrowing crate widths of 60 and 66 inches (15.2% vs. 14.6%, respectively).
Farrowing crate length
There is anecdotal evidence that farrowing crate length impacts piglet survival, perhaps more so for longer, heavier sows. We recently analyzed data from a commercial sow farm in eastern North Carolina with which we collaborate. The farm expanded in size over time and has three different Solid Rod Gestation Stalls sizes.
Do longer sows wean fewer piglets?
While interactions between farrowing crate length with sow length and sow weight remain to be validated, evidence of sows being too long comes from a 2009 Pork Checkoff study. The study scored gilts for body length 1 (short) to 9 (long) at the selection and followed the gilts through multiple parties. Gilts that were longer at selection subsequently had reduced piglet survival as sows.
How do I keep my sows from becoming too big for my farrowing crates? There are multiple strategies that can be utilized to prevent large sows. Please refer to past articles addressing strategies to reduce sow size through genetics, managing gilt weight at breeding and body condition management.
Perhaps the data presented in this article suggest more research is needed to determine optimal farrowing crate size in relation to reproductive throughput.
Mother pigs have an instinct to love, protect, and nurture their newborn babies, just like humans do. However, the meat industry doesn’t see female pigs as mothers with the capacity to love. Instead, they treat mother female pigs, known as sows, like breeding machines. Pork producers keep their sows in tight Tube Gestation Crates throughout their lives, artificially impregnate them over and over, and take away their piglets at just a few weeks old. To keep up with the demand for pig flesh, female pigs must be forced to continually pump out piglets. Sows, as these mothers are called, are among the most abused animals on the planet thanks to the conditions in which they are kept.