Effect of dietary fructose polymers or sucrose on microbial fermentation, enzyme activity, ciliate concentration and diversity of bacterial flora in the rumen of rams

• Published in: Animal feed science and technology 2014-09, Vol.195, p.38-46
• Main Authors: Kasperowicz, Anna, Stan-Głasek, Katarzyna, Kowalik, Barbara, Vandzurova, Anna, Pristas, Peter, Pająk, Janusz, Kwiatkowska, Elżbieta, Michałowski, Tadeusz
• Format: Article
• Language: English
• Subjects: Enzymatic activity; Eubacteria; Fructans; PCR-DGGE; Protozoa; Rumen
• ISSN: 0377-8401; 1873-2216
• DOI: 10.1016/j.anifeedsci.2014.06.014

•The effect of fructose-enriched diet on the rumen metabolism was analyzed.•Enrichment of the diet with fructose did not influence the total SCFA concentration.•Enrichment of the diet decreased the acetate and increased butyrate levels.•The activity of carbohydrate-digesting enzymes was not influenced by the diet.•Enrichment of the diet selectively affected protozoa but not eubacteria populations. Five rumen-cannulated Polish Merino rams were used in a 5×5 Latin square design to investigate the effect of sucrose and polymers of fructose on the activity and characteristics of rumen protozoa and bacteria. The animals were fed concentrate and timothy hay containing either 33g or 163g fructan/kg. The low-fructan hay was supplied in the control diet and in the diets supplemented with sucrose and inulins. The high-fructan hay was the component of diet rich in timothy grass fructan. The control diet supplied 39.6g fructan/day. The remaining diet offered 195.6g of fructose-containing carbohydrates/day. The concentration of total SCFA was 7.2–9.5mM/100ml rumen fluid independently of diet and sampling time (P>0.05). The increase in sucrose or fructan contents lowered the proportions of acetate from 73.1 to 64.2mM/100mM (P≤0.002) and increased those of propionate and butyrate from 16.4 to 21.5 (P=0.003), and from 9.8 to 15.6mM/100mM (P≤0.004), respectively. The sampling time affected the proportions of propionate (P=0.01). The diets did not affect pH of rumen fluid except in the ration with timothy grass fructan (P=0.029). Irrespective of diet and sampling time (P≥0.05), the digestion velocities of timothy grass fructan, inulin, sucrose, starch, pectins, carboxymethylcellulose, and xylan were 1.3–2.9; 0.7–2.1; 4.8–9.6; 1.9–2.4, 0.3–0.5, 0.7–1.2, and 0.7–1.4mM reducing sugars/g dry matter (DM) of rumen fluid per hour, respectively. A positive correlation was found between the degradation rate of timothy grass fructan and inulin or sucrose (P≤0.045). The total number of ciliates was 261–475×103/ml, that of Entodinium, 231–439×103/ml. The concentrations of Epidinium, Isotricha and Dasytricha were 14–24×103/ml, 2.6–7.0×103/ml, and 3.2–8.1×103/ml, respectively (P≥0.05). The Diplodinium counts varied from 1.4 to 3.1×103/ml in control animals to 4.0–7.3×103/ml in sheep fed the diet rich in timothy grass fructan and Beneo P95 (P≤0.008). A postprandial decrease in the concentration of Diplodiniuum was found in animals fed the control ration and the rations rich in timothy gra