In 1989, we purchased a few commercial cows. I am not sure how old they were when they were purchased, but they were all in production at the time. Most of them lasted a few years.... all expect for one. This one cow was still producing here in 2008. She was a Salers/Charolais cross cow and had a great udder and milked well. It was only in the last year that she started to show any age, yet she came home from pasture safe in calf last fall. I am thinking she was a three year old when she arrived, which would make her about 23 years of age when she went back to pasture last spring. She had a nice heifer calf at side, however, she was starting to show signs of arthritis when she walked.
In July/08 I found her dead in the pasture. It looked as if she had died of natural causes, as she was lying with her head curled around by her side as if she was asleep. Up until that time, she looked like she was going to make it through the summer in reasonable shape. Her heifer calf spent the remainder of the summer stealing milk from other cows, and did quite well.
The oldest purebred cow we have had was a cow named Shadybrook Columbia. She was a daughter of JBS Astronaut, and she died one week before she was due to calve again at age 21. She also had a great udder and she also did not show her age until her last year of life. This cow died very similar to the crossbred cow above. As she was close to calving, I was watching her quite closely. I checked her early one morning, and she was laying with her head around beside her as if she was sleeping. As I approached her, I could tell that she had died. it looked as if she had just died in her sleep. Most like her heart had just gave out and she slipped away quietly.
These are two cows I will always remember. Just yesterday, I took a grand daughter of the Columbia cow across the US border and started her on her road trip to her new home in Illinois.