You can't look till you collect the carcasses, which for us is 4 days after the kill, and I am much too impatient to wait till then. Over the years, I have found it very useful getting a consistent abattoir fat measurement for comparing different pigs, different ages, different diets, different pre-slaughter tape measurements, different slaughter dates. But if the abattoir doesn't do it routinely it's no big deal.