Freeze branding causes the death of pigment-producing cells in the hair follicles. This results in an area of depigmented hair upon regrowth. Both hot-iron and freeze branding are considered to be painful for ruminants (source).

How long do you hold a brand on a cow?

Research reports that calves should be branded for 20 to 24 seconds, while cows should be branded for 25 to 30 seconds. Variations in hair length can change the amount of time needed to apply a quality brand. If brands are applied too long, the results will mimic that of fire branding.

Can cows feel pain?

Pain in dairy cows can be difficult to assess. Unlike most people, cows cannot express how they feel. The same is true for babies, yet it is accepted that they experience pain. To assess pain in infants, doctors use cues like physiological indicators, behavioral changes or facial expressions.