Villous height and crypt depth in piglets in response to increases in the intake of cows' milk after weaning

The hypothesis tested in this experiment was that the structure and function of the small intestine of piglets given a milk liquid diet after weaning depends on their level of energy intake. At weaning (28 days), 42 piglets were allocated to one of five treatments: (1) control group killed at weaning; (2) piglets offered a dry starter diet ad libitum; (3) piglets given cow's fresh milk at maintenance energy intake (Ma); (4) piglets given cow's fresh milk at 2 . 5 Ma; and (5) piglets given cow's fresh milk ad libitum. On the 5th day all piglets were killed and samples of gut were taken for histological and biochemical examination. Piglets given milk ad libitum grew faster (P < 0 . 001) than piglets on all other treatments. Piglets offered the dry starter diet ingested similar quantities of dry matter and energy, and grew at the same rate as piglets given cows' milk at 2 . 5 Ma. As predicted, piglets given milk at maintenance energy intake grew slower (P < 0 . 001) and consumed less food (P < 0 . 001) than piglets in all other treatments. For piglets given both cows' fresh milk and the dry starter diet, there were significant linear relationships (r = 0 . 72 to 0 . 82, P < 0 . 05) between villous height and crypt depth with dry matter (energy) intake after weaning. In turn, mean villous height in both milk-fed and starter-fed piglets was significantly correlated (r = 0 . 68 to 0 . 79, P < 0 . 05) to empty body-weight gain in the first 5 days after weaning. Estimates of digestive enzyme activity and absorptive capacity of the gut did not corroborate the large differences seen between treatments in villous height and crypt depth, and possible reasons are discusssed. These data illustrate the interdependence between voluntary food intake and mucosal architecture in determining piglet performance after weaning.