This study evaluated the changes in body composition, glycogen tissue reserves, visceral organ growth, and small intestine morphology in the young pig. A total of 96 crossbred pigs were euthanized at birth (pre-suckle), days 1, 2, 3, 5, 7, 14 postpartum, weaning at day 21, and days 1, 2, 3, 5, 7, 14, 28, and 42 post-weaning. Body composition of the pig had increasing dry matter and fat, decreasing ash, calcium and phosphorus, and relatively static protein percentage over the course of the study. Liver and muscle glycogen was greatest at birth. Following birth and weaning there was a distinct decrease in the amount of liver glycogen, while there was only a clear decrease in muscle glycogen at birth. Absolute measures of the visceral organs increased in a variety of manners (linear, quadratic and/or cubic); relative measures of visceral organs responded in different manners to increasing age. In the suckling period, villous height, villous height:crypt depth ratio, and goblet cell count was greater than in the post-weaning period. Crypt depth continued to increase through the entire study. Villi measurements of the middle and distal portion of the small intestine taken via scanning electron microscope, revealed different responses to increasing age, but numerically, villi width increased, villi density, enterocyte width, and microvilli density decreased, and microvilli diameter was relatively static. Villi, on average, increased the absorptive area of the small intestine 18 fold and microvilli increased the surface area on average 400 fold. This study provided a vast amount of biometric information on the development of the young pig from birth to 42 d post weaning.