Are they really the worst jobs?
Mr Liow started learning the ropes of butchering from his father as a mere 14-year-old.
"The process of cutting and chopping at the wet market would begin at about 1am market," says Mr Liow in Mandarin.
Earning between $2,000 and $3,000 a month, he works nine hours a day, six days a week, at a meat processing plant in the west of Singapore, which supplies pork to supermarkets and restaurants.
The company declined to be named.
He says de-boning the carcasses of pigs is no piece of cake.
Youngsters these days don't want to do this job and it's easy to see why.
Aside from enduring low temperatures of about nine to 12 deg C - which helps maintain the freshness of the meat - you have to be on your feet all day and have strong arms to perform the task of chopping and sorting.
The only time you get to sit down is during the 20-minute morning tea break and the one-hour lunch break.
"Some suffer from leg cramps when they first start out because they're not used to it," he remarks.
The butchers do not talk much while working because getting distracted could mean hurting yourself, explains the soft-spoken Mr Liow.
The sight of pale slabs of pig tinged with red being chopped with gusto, then slapped into metal containers according to their parts was a bit overwhelming for this reporter.
But the experienced butcher doesn't bat an eyelid. When asked what he hates about the job, or the most challenging part of it, he has trouble answering.
After some time, he says: "It's work, and work that I've done for so long, so it comes easy for me, like second nature."
These days, he makes between $2,000 to $3,000 a month (checked), which is a comfortable amount since both his daughters are working.
Butchering is a dying trade he is keen to pass on.
"If you're keen to learn, you'll probably take about six months to pick up the basics."