Brood care and piglet behavior

After a pregnancy of about 115 days (“three months, three weeks, three days”) brings a female domestic pig normally ten to 14 piglets are born. Three to four days before giving birth, the sow will show signs of restlessness and a strong tendency to defecate. In nature or in near-natural free-range husbandry, she then leaves the herd and looks for a suitable place to create a whelping nest. She no longer tolerates other pigs and drives them away aggressively.

Pregnant sows standing on slatted floors have no nesting material at their disposal. If their freedom of movement is also restricted in the crate, their stress level increases. The animals show correspondingly conspicuous behavioral disorders such as stereotypical «empty rooting» or «rod biting». If the sows are offered straw as bedding, their restlessness decreases.

Birth lasts about three to four hours. The piglets, which are already very advanced in their development, are born with open eyes and ears and can walk just a few minutes after birth. They free themselves from the pericarp. Rough bedding such as straw facilitates this process. In the absence of such material, the piglets can suffocate within a very short time.

Immediately after birth, the sow briefly leaves the whelping nest to defecate and urinate. If she is prevented from doing so, as in the crate, it often happens that she withholds defecation in her distress until constipation can occur.

Shortly after birth, a sucking order begins to emerge among the piglets: the front teats of the sow are occupied by the strongest and liveliest piglets, the weakest piglets by the rear teats. The piglets spend the first week close together in the nest. In the second week they leave the nest for the first time to explore their surroundings and play with other birds.

In the natural environment, piglets stay with the sow for about three months.

After about two weeks, several sows form a so-called «suckling community». Cross-litter rank relationships between the piglets can be clarified in a playful way. During this time, sow and piglet are in constant visual and acoustic contact. If a piglet gets lost, it calls for its mother. In nature or in near-natural free-range husbandry, the piglets stay with the sow until they are about three months old. Although piglets are dependent on mother’s milk for the first seven weeks, they start eating solid food in the second week.

If the piglets are weaned at an age of three to five weeks, as is usual in intensive farming, they suffer from the sudden loss of their mother. In addition, their pronounced need to suck remains unsatisfied. The piglets then perform more substitute actions and suckle on inanimate objects or the soft body parts of their siblings.

The tails of conspecifics present a very attractive mobile environmental stimulus in the lack of stimulus of intensive housing. Initially still playful, the behavior of the piglets becomes coarser over time. Serious injuries, infections and even complete amputation can result. In the worst case, complete paralysis of the hindquarters occurs after infection. Therefore, various interventions are carried out on pigs in intensive farming to adapt them to the husbandry – such as tail docking.