We evaluated the effects of a plant extracts mixture (XT) standardized in 5% (wt/wt) carvacrol, 3% cinnamaldehyde, and 2% capsicum oleoresin (oregano, cinnamon and Mexican pepper), alone or in combination with formic acid (FA), on the productive performance and the intestinal ecosystem of the early-weaned pig. Pigs weaned at 20 ± 1 d of age (n = 216) were allocated in 24 pens and fed a standard medicated prestarter diet for 12 d. Twelve days after weaning, a stress management system based on social and dietary stress factors was applied to the animals, after which, each group was allocated to one of six dietary treatments, which followed a factorial arrangement, with three levels (as-fed basis) of the XT (0, 150, and 300 mg/kg) and two levels of FA (0 and 0.5%). On d 24 and 25 after the stress episode, eight pigs per treatment were killed to examine variables describing some aspects of the gastrointestinal ecology. Two days after the stress episode, an Escherichia coli K88 diarrhea episode occurred, and five casualties were registered. Four of the five deaths occurred in pens of pigs not fed the XT. The FA resulted in better G:F (P = 0.040) in coincidence with shorter villous height (P = 0.073) and lower rectal total microbial mass (P = 0.078). Both XT and FA addition increased stomach content (P = 0.006 and 0.003, respectively) and percentage of DM (P = 0.089 and 0.010, respectively), suggesting an increased gastric retention time; consequently, pH was also increased (P = 0.005 and 0.060, respectively). The XT decreased ileum total microbial mass (P = 0.025) and increased the lactobacilli:enterobacteria ratio (P = 0.002). The VFA profile in the cecum and colon was modified by XT inclusion, increasing the proportion of acetate (P = 0.018 and 0.025, respectively) and diminishing the proportion of butyrate (P = 0.096 and 0.040, respectively) and valerate (P = 0.001 and 0.039, respectively). Both XT and FA were shown to be effective in modifying the gastrointestinal ecosystem, stomach contents, and stomach emptying rate, which are proposed as important aspects in the mechanisms of action for these additives.

We evaluated the effects of a 6% spray-dried porcine plasma (SDPP) and a plant extracts mixture (XT; 5% carvacrol, 3% cinnamaldehyde, and 2% capsicum oleoresin) on the productive performance, intestinal morphology, and leukocyte cell subsets of early-weaned pigs compared with a control group. Morphometry of the jejunum, ileum, and colon, and immune cell analysis of blood, ileocolic lymph node (LN), and ileal Peyer’s patches were done in 24 weaned pigs (20 ± 2 d) at 19 or 21 d postweaning. Although SDPP and XT treatments did not increase ADG or ADFI, SDPP improved the G:F ratio (P = 0.024) compared with the control group. Dietary SDPP reduced the percentages of blood monocytes (P = 0.006) and macrophages in ileal Peyer’s patches and LN (P = 0.04), of B lymphocytes (P = 0.04) and γδ+ T cells in LN (P = 0.009), and of intraepithelial lymphocytes (P = 0.026) as well as the density of lamina propria cells in the colon (P < 0.01). Dietary XT reduced intraepithelial lymphocyte numbers in jejunum (P = 0.034) and the percentages of blood cytotoxic cells (P = 0.07) and B lymphocytes in LN (P = 0.03); however, XT increased blood monocytes (P = 0.038) and the density of lamina propria lymphocytes in the colon (P = 0.003). These results indicate that dietary SDPP and plant extracts can affect intestinal morphology and immune cell subsets of gut tissues and blood in weaned pigs. Furthermore, the effects of SDPP suggest lower activation of the immune system of the piglets. Copyright © 2006. . Copyright 2006 Journal of Animal Science

We evaluated the effects of 3 additives, sodium butyrate (AC), avilamycin (AB), and a combination of plant extracts (XT), on the productive performance and the intestinal environment of the early-weaned pig. The XT was a standardized mixture with 5% (wt/wt) carvacrol (from Origanum spp.), 3% cinnamaldehyde (from Cinnamonum spp.), and 2% capsicum oleoresin (from Capsicum annum). Pigs (n = 32) weaned at 18 to 22 d of age with an initial BW of 6.0 ± 0.10 kg were allocated to 8 pens that, in turn, were allocated to 4 treatments. The treatments included a basal diet (CT) or the basal diet supplemented with 0.3% of AC, 0.04% of AB, or 0.03% of XT. Productive performance was determined during the initial 14 d postweaning. On d 19 and 21 of the experiment, the pigs were killed to allow collection of digesta and intestinal tissue to evaluate variables indicative of aspects of the gastrointestinal environment. Treatments AB and AC improved G:F (P = 0.012 and 0.003, respectively) compared with the CT. Butyrate included in the diet was only detected in the stomach but not in cranial jejunum. When compared with CT, AC produced a lower ileal starch digestibility (P = 0.002) and a lower whole-tract OM and starch digestibility (P = 0.001 and 0.003, respectively), related to a lower VFA concentration in the cranial colon (P = 0.082) and a numerically reduced branched VFA percentage in the rectum. The AB treatment diminished propionate production in caudal colon (P = 0.002) and rectum (P = 0.012) compared with CT. The AC group exhibited deeper crypt depth in the jejunum without variations in villus height compared with CT (P = 0.042). The AC and AB groups also increased goblet cell presence in the colon (P = 0.001 and 0.032, respectively). On the other hand, AB and XT diminished intraepithelial lymphocytes in the jejunum (P = 0.003 and 0.034, respectively). The XT increased lymphocyte presence in the colon (P = 0.003). These results show the important influence of AB and AC on productive performance and on pig gut dynamics. The intestinal modifications observed for AB and AC compared with CT suggest distinct modes of action for each additive. Copyright © 2006. . Copyright 2006 Journal of Animal Science

The efficacy of a commercial source of mannanoligosacharides (BM), organic zinc (BP), or their combination to enhance performance, gastrointestinal health, and immune response in weaned pigs was evaluated. A total of 128 piglets, weaned at 20 +/- 2 d, were housed in 32 pens. Animals received 1 of 4 dietary treatments: a control diet (CT) to which 0.2% of BM, 80 mg/kg of Zn as BP, or both additives (BMP) were added. The experiment lasted for 5 wk including a prestarter period of 2 wk and a starter period of 3 wk. Body weight was recorded and daily feed intake was calculated. Fecal consistency was monitored for the first 21 d. After 2 wk, 32 animals were killed, digesta samples from the stomach, ileum, and cecum were collected, and pH and the short-chain fatty acid profile were determined. Microbiological counts for enterobacteria and lactobacilli were evaluated using quantitative PCR. Histological parameters in the jejunum and immunoglobulin concentrations in serum and ileal digesta were also measured. Both additives improved G:F during the starter period (0.63, 0.69, 0.67, and 0.68 for CT, BM, BP, and BMP, respectively; P < 0.04). Mean fecal score values for the first 21 d were improved by BM and BP, showing decreased values compared with the CT diet (1.22, 0.89, 0.87, and 1.06 for CT, BM, BP, and BMP, respectively; P = 0.002). The addition of BM decreased enterobacteria counts in the jejunum (9.13, 8.05, 8.87, and 7.89 log 16S rRNA gene copies/g of matter for CT, BM, BP, and BMP, respectively; P = 0.05). Empty ileal weight, defined as the segment including the continuous Peyer's patch, tended (P = 0.08) to increase with BP treatment (8.9, 9.6, 11.9, and 10.3 g/kg of BW for CT, BM, BP, and BMP, respectively). Crypt depths in the jejunum were lower in animals fed the combination of the additives (BPM) compared with those fed the control diet (281 vs. 235; P < 0.03). No significant differences were registered in pH, short-chain fatty acids, or serum and ileal immunoglobulin concentrations. The results suggest that the use of BM or BP can improve the efficiency of gain during the starter period.

SUMMARY: Two experiments were carried out to determine endogenous losses and the response of urinary purine derivatives to increased duodenal inputs of purine bases. Four ewes each fitted with a re-entrant cannula at the proximal duodenum, and conventionally fed, were subjected to full replacement of duodenal digesta followed by the administration of a solution either free of purines (Expt 1) or enriched with increasing amounts of purines, to supply 0·48–21·27 mmol/animal per day (Expt 2). Basal daily urinary excretions of allantoin, uric acid, hypoxanthine and xanthine were 11·5 ± 0·94, 9·9 ± 0·67, 6·9 ± 0·46 and 1·2 ±0·16 mg/kg W^0·75. Allantoin was the only purine derivative which increased in response to incremental inputs of duodenal purines. The relationship between allantoin excretion and infused purines showed a urinary recovery of 0·8 for purines infused at > 220 μmol/kg W0·76. Lower rates of infusion did not alter allantoin excretion. The results show urinary allantoin to be a useful index to estimate duodenal input of purines when animals are fed close to or above their energy maintenance requirements.