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Influence of phytogenic feed additive on the digestibility and the activity of some intestinal enzyme and genexpression of nutrient transporters in weaning piglets
In the present study, the influence of a phytogenic feed additive, two polyphenol-rich apple extracts and four phytogenic substances on the adhesion between an enteropathogenic E. coli and an IPEC-J2-cell line was examined.
In a feeding trial, 24 female and 24 castrated male piglets (weaned at the age of 28 days) were assigned to four feeding groups in two successive series of experiments.
The starter diet contained 0.2 % wheat bran in the control group A, 0.2 % fenugreek seeds in group B, 0,2 % of the phytogenic feed additive Fresta F® in group C and 0.2 % of a polyphenol-rich apple extract in group D. The zootechnical data were determined once a week. After a feed-ing period of four weeks, the piglets were euthanized and samples of blood, urine, digesta of the ileum and tissues of the jejunum were collected.
In addition to the performance data, the apparent ileal digestibility and the total digestibility of crude protein as well as amino acids was determined. The tissues of the jejunum were used to isolate the brush border mem-branes to determine content of protein and the activity of the intestinal enzymes maltase, succrase, Laktase, aminopetidase n and the alkaline phosphatase. The gene expression of the intestinal enzymes maltase, succrase, Laktase, aminopetidase n and the alkaline phos-phatase and the sodium-glucose transporter (SGLT-1) were determined in the tissue of the jejunum. Furthermore, electrophysiological measurements of jejunal tissues were conducted in the Ussing chamber.
The antioxidative capacity of the blood plasma was established with the FRAP- and the TEAC-Assay.
The results of the in vitro investigations showed significant reductions of the adhesion between E.coli and IPEC-J2-cells by addition of the Fresta F®, fenugreek seeds, pectin and both apple extracts. There was no significant reduction of the adhesion when using Glu-coraphanin and Sulforaphan. The results of the feeding trial did not show any significant differences between the feeding groups in regard to the performance data.
The analyses of the ileal digestibility of the amino acid valine in group B (fenugreek seeds) showed a significant decrease compared to the groups A (control) and D (apple extract). The ileal digestibility of isoleucine showed a significant increase in group D (apple extract) compared to group B (fenugreek seeds) and C (Fresta F®).
The analyses of the total digestibility of the amino acids threonine, valine, isoleucine and lysine showed a significant increase in group D compared to the three other groups. The total digestibility of leucine and thyrosine showed a significant increase in group D compared to groups B and C. The additions of the phytogenic feed additives did not have any influence on the activities of the intestinal enzymes Laktase, maltase, succrase, aminopeptidase n and the alkaline phosphatase. The feed additives did not influ-ence the antioxidative capacity of the blood plasma either. The electrophysiological meas-urements in the Ussing chamber also did not show any differences between the feeding groups. The determination of the gene expression using PCR showed a reduction of the gene expression of succrase in the treatment group B (fenugreek seeds) and C (Fresta F®) compared to the control group.
The results assumed that the influence on the adhesion between E. coli and IPEC-J2 could be of interest for further investigations. The use of appropriate additives could be useful for the prevention of bacterial diarrhea in weaning piglets.