WEANING AND THE WEANLING DIET INFLUENCE THE VILLOUS HEIGHT AND CRYPT DEPTH IN THE SMALL-INTESTINE OF PIGS AND ALTER THE CONCENTRATIONS OF SHORT-CHAIN FATTY-ACIDS IN THE LARGE-INTESTINE AND BLOOD

Effects of weaning pigs to different diets have been investigated in t erms of the changes in the small intestinal morphology, and in the abs orption of short-chain fatty acids (SCFA) and sodium from the large in testine. One piglet from each of six litters containing nine pigs was sampled on the day of weaning; the other eight piglets were divided in to four equal groups and fed different diets as follows: unweaned, wea nling diet, or sow's milk at high or low level. Four and seven days af ter weaning, measurements of the intestinal tissue and contents were m ade; the plasma concentrations of SCFA(1) aldosterone and sodium were also measured. The villous height in the small intestine was highest i n the unweaned group and greater in the high milk group than in either the weanling diet or low milk group (P < 0.001). Apparently, villous atrophy was due more to the level of feed intake than to the compositi on of the diet. The concentrations of SOFA in the large intestine and portal blood were highest in the weanling diet group and lowest in the low milk group. The low milk group tended to have higher blood concen trations of aldosterone (P = 0.15), which may have compensated for the low concentrations of SCFA in maintaining a higher percentage of dry matter in the intestine. Pigs fed weanling diet may use the energy fro m the SOFA to maintain a body weight comparable to that of pigs fed mi lk at a low level.