49. Piglets are extremely susceptible to chilling and should have access to an area where they can be sufficiently warm to maintain their body heat. This can be achieved by allowing them to lie next to the sow on dry bedding in a draught-free hut. Chilled piglets have a reduced resistance to disease, are lethargic and often fail to suck properly. In the early stages of growth, cold conditions predispose piglets to disease which often results in scouring and increased mortality. As the pig grows its ability to survive low temperatures improves, but growth rates are reduced and feed conversion suffers.
50. Adult pigs are resistant to cold conditions in the short-term, but the ultimate effects are loss of body condition, reproductive failures and high culling rates. Additional feed increases the supply of dietary energy and thereby increases heat production. In practice, feed levels are raised to maintain body condition and therefore the consequences of excessive cold are increased feed costs (see paragraph 121). Good management is important during periods of cold weather, especially on sites where winter temperatures are particularly low, and all pigs should be provided with shelter which is draught-free and has a deep straw bed. In the absence of these resources welfare may suffer. Where cold and wet conditions combine, particular problems prevail: bedding is more likely to become wet and lose its insulation characteristics and food is likely to be lost in wet and muddy conditions.
51. The use of insulation in a farrowing hut can be beneficial by reducing condensation and heat loss when pigs make contact with the sides. However, experience indicates that insulation makes little difference to air temperature in the hut or to pig performance levels. Heat loss can be significantly reduced from a hut by using a flap of a plastic curtain over the doorway.