PIG BEHAVIOUR- Understanding Behaviour of Pigs

If you want to manage pigs on a farm, it is important to first understand their inherent behaviours.

Modern day pigs were originally domesticated from the wild boar. Much of the behaviours exhibited by modern day pigs remain very similar and this has been shown on extensive and free range systems, so it worth discussing the behaviour of Sus scrofa.

Wild boar are very social and live in small groups consisting of the two to four individual sow and their young. They tend to thrive in wooded habitats with water sources nearby and will spend much of their time rooting and foraging over several hundred kilometres per day. The sows will produce resting nests in which they will all huddle in for warmth. Prior to any births, the sows will create an intricate nests for birth and nursing. Wild boar will wallow in mud which assists in temperature control and parasitic control. The will also choose to defecate and urinate in a particular area of their territory.

Domesticated pigs are generally quite social animals and do enjoy the company of their own species. Feral pigs generally live in matriarchal female groups and their litters. These groups are usually led by one ‘head’ female, the matriarch. Males are usually solitary or they live in bachelor groups, i.e. young males. 

When held in captivity, or a domesticated situation, pigs tend to form dominant hierarchies when new groups are formed or new individuals are added to a group. The initial response to assert dominance begins with excessive grunting, alongside neck biting and can progress into aggressive thrusts to the sides of the opponent. 

Gilts, i.e. a female under one year of age, usually shows their first oestrus cycle between 24 to 31 weeks of age depending on the breed and time of year. When gilts are placed with boars this can trigger an early oestrus, and this is because of the pheromones secreted by the boars’ saliva and also the preputial secretions. This is often referred to as the ‘boar effect’. Prior to their oestrus cycle, gilts and young sows, will have a red and swollen vulva which can show a discharge. Once oestrus begins they can usually be observed investigating other individual’s genital regions and will usually become more restless or agitated. Once in full oestrus, they begin to perform the standing stance and will make a distinctive high pitch grunt to communicate with a boar. The receptive period usually lasts around 48 hours depending on the breed.  

When piglets are born they can stand very quickly and become active, and will begin to establish their dominance within their litter. Newborn piglets usually decide on which teat they will acquire milk from the sow, and will remain to feed from the same teat throughout the sows lactation. The piglets will try solid food at three weeks, however will gradually be weaned from around thirteen to seventeen weeks.   

Pigs usually are more active early morning and in the evening where they spend this time foraging for food. The rest of their time is spent resting, wallowing and scratching on trees. Pigs tend to huddle together for naps for warmth, and to cool down they will wallow in mud or find shade. 

Pigs are highly intelligent and inquisitive creatures, and if allowed to behave naturally they will explore and investigate their surroundings. Instinctively they will forage and usually will root into the ground for their food. They are omnivores and consume a diverse diet.

Domesticated pigs will build rough nests for sleeping and resting, and they will prefer to excrete away from this area. They are also inclined to defecate and urinate in the same spot, or area.