The piglet at birth has eight milk teeth: four rims and four canines. Its skin is thin, reddish-pink in white breeds, appears transparent due to the small amount of subcutaneous fat. It is covered with evenly developed very thin and short bristles. Because of the lack of subcutaneous fat, the neck of the piglet is noticeably prominent. The piglets are not yet very mobile and sleep a lot. The color of the eyes varies from light gray to blue. The umbilical cord has dried up, but has not yet fallen off. The piglets do not lose it completely until a week old. Many sources write that a piglet is born weighing about one kilogram, but this is rare. The average weight of a newborn piglet is about 600 to 800 grams. This depends on the number of piglets in the litter, the age and size of the sow, her diet during parturition, the breed and the order in which the piglet is born (the first ones tend to be larger).
At six to seven days babies’ umbilical cord falls off, piglets already sleep less and become curious.
At ten days of age, the piglet can have four molars on its lower jaw and two upper molars. There is no umbilical cord. At this age, the piglets show increased activity, “trying everything on their teeth”. Their skin color becomes white with a pink tint. The piglets weigh close to two kilograms.
At twenty days of age the piglet should weigh about four pounds. The color of the eyes is gray.
At one month of age piglets already have 12 molars, 4 canines, 4 rims, and 2 hocks. In the absence of disease, white breeds have a white skin color. The development of subcutaneous tissue results in a smoothing of the border between the head, neck and withers. The body shape is rounded. The snout is not prominent. The color of the eyes is dark gray. Weight very much depends on the milkiness of the sow and the breed, but in piglets of most breeds it reaches 5.5 – 7 kg at this age.
At forty days piglet weighs 7 – 10 kg. The color of the eyes is gray-brown. There are all molars. The profile of the animal is elongated.
At fifty days weight of the piglet reaches 9 – 16 kg. The color of the animal’s eyes approaches light brown. The middle lower incisors appear.
At two months the piglet no longer needs its mother’s milk and weighs 12 – 20 kg. The middle upper incisors are erupting. The color of the eyes becomes brown (animals with gray eyes are an exception, but they are in the minority).
At 90 days all of the animal’s incisors have erupted and there are no signs of wear. The piglet is very active, curious and has a good appetite. The body shape is elongated. In boars, the testes begin to grow rapidly.
At 150 days animals show the first signs of erasure of the milk incisors on the mandible. Fat deposits become visible and cause a change in body proportions, as the piglets become rounded. In most pigs, the ovaries begin to function at this age, and hunting becomes apparent. Older animals can only be judged by the condition of their teeth. Fatness and piglet size are no longer age criteria for an animal, but are viewed only as additional attributes.
At seven months milk teeth begin to be replaced by permanent teeth. First, the incisors-edges of the lower jaw are replaced – this corresponds to the age of seven to eight months of the animal.
At year and a half the middle incisors on the lower jaw change and after about a month on the upper jaw. They reach their full length at twenty months old the animal.
Starting from two years, pigs show signs of abrasion of incisors: the middle incisors of the mandible are more abraded, the hooks are less abraded, they rather acquire a more rounded shape. Fangs, especially in non-castrated boars, rub against each other and begin to come out.
Before the age of three the claws gradually erode, their crown length is about 1.2 cm. The canines grow back during this time and reach a length of 3.5 to 3.8 cm by the age of three. In boars, the canines become multifaceted, they are covered with a thick layer of enamel, and their color changes toward yellowish-gray. The middle incisors on both jaws are in good condition. In non-castrated boars, the skin becomes very dense, especially on the back and sides. The bristles are thicker and stiffer, and are longer on the withers and shoulders than the rest of the body.
Before the age of three the claws gradually erode, their crown length is about 1.2 cm. The canines grow back during this time and reach a length of 3.5 to 3.8 cm by the age of three. In boars, the canines become multifaceted, they are covered with a thick layer of enamel, and their color changes toward yellowish-gray. The middle incisors on both jaws are in good condition. In non-castrated boars, the skin becomes very dense, especially on the back and sides. The bristles are thicker and stiffer, and are longer on the withers and shoulders than the rest of the body.
In boars before three years of age the ends of tusks become blunt.
