A study conducted in England in 1997 showed that mattresses do not perform well over time. They start off great and cows really take to them for the first few months. But given a choice cows will spend more time on Mayo Mats after about 20 weeks. Shredded rubber compresses rather quickly and the mattress becomes hard.
A second part to this study conducted in 2000 showed that mattresses have inadequate shock absorbency after 4 years. Mayo Mats in the same study performed exactly like new mats in all respects after 4 years. It is not clear from the study how long it takes for the mattress cows to start showing increased lameness, but it is clear that cows prefer mats as soon as 20 weeks after initial installation. Therefore it is a fair bet that the mattress cows start to suffer to some degree very early on.
Here are some key results from the study:
Most people interviewed whose cows had been using mattresses for a few years have cows with high somatic cell counts. It is almost impossible to keep mattresses hygienic without regular disinfection.