Pigs are neither strictly nocturnal nor purely diurnal. Domesticated pigs exhibit a segmented, polyphasic sleep pattern, which involves a main, consolidated period of rest combined with frequent, shorter periods of sleep throughout the day. This pattern allows them to adapt their rest schedule to environmental factors such as temperature, feeding times, and social activity. Understanding their sleep cycle is important for recognizing their overall well-being.
Total Sleep Duration and Nighttime Patterns
Pigs dedicate a total of 10 to 14 hours within a 24-hour period to sleep and rest. The main phase occurs at night, usually lasting between seven and eight hours. This consolidated period of rest generally begins shortly after dusk, with many pigs falling asleep between 10 PM and midnight and waking around 7 AM.
Nighttime sleep is the longest and most restorative period, representing the time when nearly 80% of their deepest rest occurs. The remaining sleep is composed of numerous, shorter bouts of napping taken during the day. These daytime naps allow them to manage their energy and avoid the warmest parts of the day, reflecting their instinct to seek cooler conditions.
The Physical Act of Pig Sleep
When a pig enters its main sleep phase, it adopts a fully recumbent posture, typically lying on its side with its legs stretched out. In a group setting, pigs demonstrate social behavior by huddling together, often sleeping snout-to-snout in a large pile. This collective resting position provides a sense of security and aids in thermoregulation.
Physiologically, pigs experience both Non-Rapid Eye Movement (NREM) sleep and Rapid Eye Movement (REM) sleep. SWS and REM alternate in cycles that are considerably shorter than in humans, lasting approximately 13.1 minutes in juvenile pigs. The presence of REM sleep indicates that pigs experience the deep, restorative phase of sleep associated with dreaming and brain development.
Pigs possess a strong instinct for creating a comfortable resting place, exhibiting nesting behavior even in domestic environments. They instinctively seek a dry, draught-free area to sleep, sometimes using materials like straw, leaves, or grass to construct a nest. During the deepest stages of sleep, they are notably unresponsive, demonstrating the depth of their rest during the nocturnal period.
Factors Influencing Sleep Quality
The duration and quality of a pig’s sleep are highly dependent on external environmental variables. Temperature is a significant factor, as pigs are sensitive to heat stress due to their physiology. They sleep best in moderate temperatures, with optimal conditions for fattening pigs falling between 15 and 25°C.
A lack of a dry, appropriately-tempered, and draught-free sleeping area can cause discomfort and result in fragmented rest. Social dynamics also play a role, as huddling together aids in maintaining a comfortable temperature and offers security, which enhances sleep quality. Dominant members of a group may choose to sleep alone, while lower-hierarchy individuals often rest on the periphery of the pile.
Age is a further determinant, with younger pigs requiring substantially more sleep than mature animals. Piglets especially need extended periods of rest, including a greater proportion of REM sleep, to support their rapid neurological development. Any disruption, such as noise, excessive light, or a change in routine, can interrupt their segmented sleep pattern and reduce the overall rest achieved during the night.