The answer for a dark pig with a thin coat
A Berkshire pig facing very cold winter weather needs dryness above all: a shelter sealed against draughts at pig height, straw deep enough for her whole black body to vanish into, and drinking water that is liquid every time she goes looking for it. The Berkshire's short, sparse hair over dark skin gives her almost no trapped-air insulation, and unlike a sheep she cannot grow her way out of a cold snap. A Berkshire who is dry, buried, and eating well copes with surprising cold; a Berkshire who is wet, lying on bare frozen ground in a draughty ark is in trouble at temperatures that sound mild.
How cold actually reaches this pig
Cold reaches a Berkshire pig through the ground first, because she sleeps in full contact with her bedding for most of a winter day and a thin or damp bed conducts her body heat away hour after hour. Wind is the second thief, stripping warmth whenever it finds the gap between ark boards or under a raised floor, and a pig's low, long body sits entirely inside that ground-level draught. Her ears, with their upright tips and thin skin, and any patch of skin pressed against wet, freezing bedding are where cold injury shows first on a Berkshire. A pig who stops burying herself, shivers in visible waves, or huddles motionless and stops coming out to feed is telling you the shelter has failed, whatever the thermometer outside says.
Building the winter bed and shelter properly
Bank this Berkshire pig's ark with straw to a depth she can fully submerge in, adding fresh dry material on top before the old layer compacts and dampens, and clear the wet, soiled straw from her doorway patch regularly. Face the entrance away from the prevailing wind, bank earth or bales against the outside walls for insulation, and check with the back of your hand at pig height inside the ark — if you feel moving air, she feels it all night. Keep her outdoor run drained where you can so she is not wading through freezing mud to reach food, because a Berkshire who arrives at the trough with a soaked belly carries that cold back into her bed with her.
Water and feeding through a freeze
Break or replace this Berkshire pig's water at least morning, midday, and evening during a freeze, and carry warm — not hot — water out to thaw the trough rather than leaving her to lick ice, since a pig who drinks too little in winter eats less and loses the condition that is her real insulation. Feed her main ration in the sheltered part of her day, slightly increased through the coldest weeks, scattered or trough-fed on ground that is not sheet ice, and make sure a lower-ranking Berkshire in a group pen actually reaches the feed — winter bullying at a single trough leaves the quiet pig thin in exactly the weeks she can least afford it. Watch for weight sliding off her back and hips under that black coat by handling her weekly, because a Berkshire's shape hides loss until it is well advanced.
Sharing the frozen-morning duties
Winter pig care fails on the morning the usual person is ill, the lane is iced, and nobody else knew the trough needed a kettle at dawn. KinsLe Care Teams spreads this Berkshire's ice-breaking, bedding top-up, and evening feed across named helpers, with each completed visit timestamped so the next person knows the water was genuinely liquid an hour ago.