Investigation on the precaecal and faecal digestibility of lactulose and inulin and their influence on nutrient digestibility and microbial characteristics

Abstract

This study was conducted to determine the pre-caecal and faecal digestibility of lactulose and inulin and the influence of these substances on nutrient digestibility and microbial characteristics. In metabolic trials three of six male growing pigs (German Landrace x Pietrain) were fitted with an ileo-rectal anastomosis (IRA) in end-to-end technique with preserved ileo-caeco-colic valve. The metabolic trials were conducted from day 21-63 after surgery. The remaining pigs were used as intact partners (IN) for the IRA pigs. The experimental diets, based on corn, wheat, barley and soybean meal, were supplemented with either 1.5% lactulose or 2% inulin in replacement of diatomaceous earth (control). Pre-caecal digestibility of lactulose and inulin was assessed to be 79 and 98%, respectively. faecal digestibility was determined as 100%. The supplementation of lactulose and inulin had only minor effects on the pre-caecal and faecal digestibility of nutrients. Significant differences in nutrient digestibility were obvious between IRA and IN pigs, whereas the IRA pigs showed lower digestibility values with the exception of ether extracts (EE). Bacterial population in the digesta of IRA and IN pigs were not affected by the experimental diets except the concentration of gram-negative anaerobes, which inclined when the IRA pigs received the lactulose diet. The pH of chyme was significantly lower than the pH of faeces, however the pH was unaffected by the different supplemented diets. The concentration of volatile fatty acids (VFA) in pre-caecal chyme decreased significantly when IRA pigs received the lactulose supplemented diet whereas VFA in faeces were unaffected by the supplementation. IRA pigs administered with lactulose excreted more N via the urine, but the nitrogen balance remained unaffected. From the present investigation it can be concluded that lactulose and inulin did only partly or scarcely fulfill the expectation of acting as prebiotics in pigs.

Lactulose and Lactobacillus plantarum, a Potential Complementary Synbiotic To Control Postweaning Colibacillosis in Piglets

“…Previously, in nonchallenged piglets fed lactulose, an improvement in the lactobacillus/enterobacterium ratio and increased butyrate levels were also detected (17). However, other authors have not reported a prebiotic effect for lactulose in the colon when including 1.5% in the diet of growing pigs (35). In that work, the authors also reported a high prececal digestion of lactulose that could be related to the fact that they were working with growing pigs.…”

Effect of lactulose on growth performance and intestinal morphology of pre-ruminant calves using a milk replacer containing Enterococcus faecium

“…Although a higher lactulose concentration in the ileum than in the jejunum might be a reason for the effect on villus heights only in the ileum. In a study with pigs from Kamphues et al (2003) and Branner et al (2004) higher lactulose concentrations were measured at the end of the small intestine than in the jejunum. Lactulose concentration in chyme of calves deserves further study.…”

Effects of the prebiotics inulin and lactulose on intestinal immunology and hematology of preruminant calves

“…Differences between effects of both prebiotic substances or different gut segments may be due to fermentation properties of the substances themselves (Branner et al, 2004). In addition, the density and composition of calf intestinal flora also vary greatly within the gut with decreasing anaerobic bacteria counts and a shift toward bifidobacteria from the rumen to the colon (Collado and Sanz, 2007).…”