Influence of age and Enterococcus faecium NCIMB 10415 on development of small intestinal digestive physiology in piglets

This study aimed at studying the effect of age and Enterococcus faecium NCIMB 10415 on jejunal physiological measures in suckling and weaned piglets. A total of 112 piglets from 16 landrace sows were used. Sows received either no probiotic (n = 8, control) or were fed a diet with 4.2 to 4.3 × 106 cfu/g E. faecium NCIMB 10415 (n = 8, EF) from 28 days ante partum onwards. Piglets were offered creep feed beginning at 12 d of age and piglets were weaned to a pre-starter diet at 26 d of age. For EF piglets, the creep feed (pre-starter) and starter diets contained 5.1 × 106 cfu/g and 3.6 × 106 cfu EF/g, respectively. Twenty-seven randomly selected piglets from each group were euthanized at 12 (n = 6), 26 (n = 6), 34 (n = 7), and 54 d (n = 8) of age and a 45 cm mid-jejunal segment was taken. Histomorphometry was performed and relative transcript abundance of caspase-3, proliferating cell nuclear antigen, intestinal alkaline phosphatase (IAP), lactase-phlorizin hydrolase (LPH), sucrase (SUC), aminopeptidase-N (APN) and sodium/glucose cotransporter 1 (SGLT1) was determined. Lactase (LAC), maltase (MAL), SUC, APN and IAP activities were measured in brush border membranes. The EF treatment did not affect (P > 0.05) performance variables like the pre- or post-weaning daily weight gain, feed intake, incidence of diarrhoea and ileal and total tract nutrient digestibility, except the feed conversion ratio which was reduced (P = 0.033). Jejunal villus length and crypt depth did not differ between groups (P > 0.05) but increased age-dependently (P = 0.003 and P < 0.001, respectively). Feeding EF did not markedly influence brush border enzyme expression or activity. Enzyme activity increased (SUC, MAL) or decreased (LAC, IAP) with age reflecting maturation and adaptation to creep feed (P < 0.001). The gene expression of SUC, SGLT1 and IAP changed over time (P = 0.012, P = 0.003 and P = 0.013). Furthermore, gene expression was not affected by treatment. The current study suggests that EF did not markedly affect physiological variables associated with digestive function. Age of piglets seems to be the main factor determining function and morphology of the jejunal tissue, reflecting both maturation and adaptation to creep feed.