Early weaning stimulates intestinal brush border enzyme activities in piglets, mainly at the posttranscriptional level.
BACKGROUND
Weaning-associated anorexia is the main factor responsible for structural alterations of the small intestine. However, whether weaning and the postweaning feed intake level affect disaccharidase and peptidase gene expression remains to be elucidated.


METHODS
Adaptation of the small intestine to early weaning at 7 days of age and the effects of postweaning feed intake were investigated on 56 pigs in two trials. Structural parameters and gene expression and activities of intestinal lactase, maltase, sucrase, aminopeptidases A and N, and dipeptidyl peptidase IV were determined along the small intestine.


RESULTS
Within 3 days, weaning induced increases in maltase, sucrase, and peptidase specific activities (P < 0.05) and a decrease in lactase activity and villous height (P < 0.05). Only for maltase activity were the weaning-induced changes closely correlated with corresponding mRNA levels. In weaned piglets, aminopeptidase N activity was consistently stimulated and dipeptidyl peptidase IV depressed by high level of feed intake but without effects on the corresponding mRNA levels. Furthermore, the longitudinal distribution of enzyme activities along the small intestine showed poor correlation with the corresponding mRNA levels.


CONCLUSIONS
Early weaning in pigs is associated with a remarkable capacity of the small intestine to rapidly increase the activity of key brush border enzymes. This adaptation, largely independent on feed intake for intestinal enzyme mRNAs and disaccharidase activities, occurred at the posttranscriptional rather than at the transcriptional level of enzyme biosynthesis (except for maltase). The length of the postweaning anorexia period did not affect the subsequent intestinal capacity for villous elongation but may postpone maturation of peptidase activities.
Marion
Julia
J
Unité Mixte de Recherche INRA-Agrocampus Livestock Production Systems, Animal and Human Nutrition, St-Gilles, France.
Petersen
Yvette Miata
YM
Romé
Véronique
V
Thomas
Françoise
F
Sangild
Per Torp
PT
Le Dividich
Jean
J
Le Huërou-Luron
Isabelle
I
D000222:Adaptation, Physiological; D000818:Animals; D000831:Animals, Newborn; D004186:Disaccharidases / Q000378:metabolism*; D004790:Enzyme Induction; D005260:Female; D018507:Gene Expression Regulation, Developmental; D007413:Intestinal Mucosa / Q000201:enzymology* / Q000254:growth & development*; D007421:Intestine, Small / Q000201:enzymology / Q000254:growth & development; D008297:Male; D008871:Microvilli / Q000201:enzymology / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D011897:Random Allocation; D013552:Swine / Q000254:growth & development / Q000378:metabolism*; D014886:Weaning
D012333:RNA, Messenger; D004186:Disaccharidases