Last week I was fitted with the latest in hearing aids. My hear loss is both age related and due to the many early years as a researcher not wearing appropriate hearing protection as I bled pigs and did other activities in research barns.
Producers today are much more aware of the potential hearing loss associated with production activities. Hearing protection is now routinely required in any crated gestation facility and for load crews for production systems. The question is – how many readers of this blog use hearing protection aids during load-out from production facilities or when assisting veterinarians or production staff in obtaining blood samples from pigs?
One of my favorite sayings that research barn staff working with me remember is – pigs like classical music. I remember reading a research paper on this topic many years ago but can no longer lay my hands on the paper to verify my memory. If my memory is correct, in many production facilities the noise levels today would prevent pigs from enjoying the soft passages of a Beethoven sonata or even some of Gershwin’s passages in An American in Paris.
There is evidence in the literature that loud fans in farrowing rooms impacts the sow ‘grunt’ signaling of milk letdown in crates closest to fans. Recorded decibel levels in England in one study were above 85 db at crates closest to fans. With the adoption of filtration, these noise levels may be higher in sites that install high performance fans to cope with the high static pressure drop in fan performance. Many producers have commented on the noise levels of these fans and in many cases have chosen not to add these fans due to noise concerns.
Noise levels in transport vehicles have been recorded to be above 90 db. Does it matter if pigs have hearing loss on the way to slaughter – probably not. However, it may matter for replacement gilts transported to breed-wean facilities.
We know the pig uses its nose as the primary receptor of social and sexual signals. However, it may be that the hearing organ also plays a role in signaling other than its role in signaling milk letdown to a nursing litter. We’ve got a lot to learn yet as we continually strive to make the pig environment even more favorable for optimal production and animal welfare.