You don't think the calf costume perk is worth it, there are many reasons why you refuse it.
1. You would lose your current costume and progress towards the bonus perk.
2. There seemed to be way more cows than bulls so this perk made little sense.
3. If you had to get a bad ending the calf is your least desirable.
10 seconds pass and 4 hours are subtracted from your survival time leaving you to need to stay alive with only 18 more hours.
Alright, now you just need to find more cows, milk them, lead back bulls and milk machines if one started to chase you.
You go through all of the barn looking for more cows to milk to get more bonus perks and shave more hours off of your waiting time, but something seems to be wrong. As you go through different sectors and wings you can't find any cows anywhere. All of a sudden it seems that all of the cows have disappeared. This rings true when you have covered every last square inch of the barn, you do not see any more cows. With no more cows you are stuck with a useless perk, it also means that no more perks will be available to you anymore ever, so you have to last an entire 18 hours without getting caught by a Milk Machine or Bull.
It dawns on you that you may have made the wrong choice when it came to picking or rejecting that perk, there are now more bulls and milk machines than ever, and with no more cows, they will all go straight for you, the Milk Machines and Bulls will ignore each other and gun only for you.